document_title: Emerald ash borer

question_text: where is the emerald ash borer found in the us

text: Emerald ash borer

text: History[edit]

text: The French priest and naturalist Armand David collected a specimen of the species during one of the trips he took through imperial China in the 1860s and 1870s. He found the beetle in Beijing and sent it back to France, where the first brief description of Agrilus planipennis by the entomologist Léon Fairmaire was published in the Revue d'Entomologie in 1888.[2] Unaware of Fairmaire's description, a separate description naming the species as Agrilus marcopoli was published in 1930 by Jan Obenberger.[2]

text: Identification[edit]

text: Adult beetles are typically bright metallic green and about 8.5 millimeters (0.33 in) long and 1.6 millimeters (0.063 in) wide. Elytra are typically a darker green, but can also have copper hues. Emerald ash borer is the only North American species of Agrilus with a bright red upper abdomen when viewed with the wings and elytra spread. The species also has a small spine found at the tip of the abdomen and serrate antennae that begin at the fourth antennal segment.[3] Adults beetles of other species can often be misidentified by the public.[4]

text: Life cycle[edit]

text: The emerald ash borer life cycle can occur over one or two years depending on the time of year of oviposition, the health of the tree, and temperature.[5]

text: After 400–500 accumulated degree-days above 10 °C (50 °F), adults begin to emerge from trees in late spring, and peak emergence occurs around 1000 degree-days. After emergence, adults feed for one week on ash leaves in the canopy before mating, but cause little defoliation in the process.[6] Males hover around trees, locate females by visual cues, and drop directly onto the female to mate; mating can last 50 minutes, and females may mate with multiple males over their lifespan.[7] A typical female can live around six weeks and lay approximately 40–70 eggs, but females that live longer can lay up to 200 eggs.[6]

text: Eggs are deposited between bark crevices, flakes, or cracks and hatch about two weeks later. Eggs are approximately 0.6 to 1.0 millimeter (0.02 to 0.04 in) in diameter, and are initially white, but later turn reddish-brown if fertile.[6][5] After hatching, larvae chew through the bark to the inner phloem, cambium, and outer xylem where they feed and develop.[7] Emerald ash borer has four larval instars. By feeding, larvae create long serpentine galleries. Fully mature fourth-instar larvae are 26 to 32 millimeters (1.0 to 1.3 in) long.[5] In fall, mature fourth-instars excavate chambers about 1.25 centimeters (0.49 in) into the sapwood or outer bark where they fold into a J-shape.[7] These J-shaped larvae shorten into prepupae and develop into pupae and adults the following spring. To exit the tree, adults chew holes from their chamber through the bark, which leaves a characteristic D-shaped exit hole. Immature larvae can overwinter in their larval gallery, but can require an additional summer of feeding before overwintering again and emerging as adults the following spring.[5] This two-year life cycle is more common in cool climates, such as European Russia.[8]

text:
Larva

Pupa removed from its pupal chamber.

Adults exit the tree from D-shaped holes.

Dorsal view of adult with elytra and wings spread.

Underside of an adult emerald ash borer.

text: Range[edit]

text: The native range of the emerald ash borer is temperate northeastern Asia, which includes Russia, Mongolia, northern China, Japan, and Korea.[9][8]

text: The beetle is invasive in North America where it has a core population in Michigan and surrounding states and provinces. Populations are more scattered outside the core area, and the edges of its known distribution range north to the upper peninsula of Michigan, south to northern Louisiana, west to Colorado, and east to Massachusetts [10] In northern Europe, a population was found in Moscow, Russia in 2003.[8] From 2003 to 2016, this population has spread west towards Sweden at 40 km (25 mi) per year and is expected to reach central Europe between 2031 and 2036.[11][12][8]

text: Host plants[edit]

text: In its native range, emerald ash borer is only a nuisance pest on native trees, as population densities typically do not reach levels lethal to healthy trees.[13] In China, it infests native F. chinensis, F. mandshurica, and F. rhynchophylla; in Japan it also infests F. japonica and F. lanuginosa.[8]

text: Emerald ash borer primarily infest and can cause significant damage to ash species including green ash (Fraxinus pennsylvanica), black ash (Fraxinus nigra), white ash (Fraxinus americana), and blue ash (Fraxinus quadrangulata) in North America.[14] In Europe, Fraxinus excelsior is the main ash species colonized by EAB.[8] Ash susceptibility can vary due to the attractiveness of chemical volatiles to adults, or the ability of larvae to detoxify phenolic compounds.[7] Emerald ash borer has also been found infesting white fringe tree in North America, which is a non-ash host, but it is unclear whether the trees were healthy when first infested, or were already in decline due to drought.[7][15]

text: Adults prefer to lay eggs on open grown or stressed ash, but readily lay eggs on healthy trees amongst other tree species.[7] Young trees with bark between 1.5 millimeters (0.059 in) to 5 millimeters (0.20 in) are preferred.[8] Both males and females use leaf volatiles and sesquiterpenes in the bark to locate hosts.[7] Damage occurs in infested trees due to larval feeding. The serpentine feeding galleries of the larvae disrupt the flow of nutrients and water, effectively girdling (killing) the tree as it is no longer be able to transport sufficient water and nutrients to the leaves to survive.[6]

text: As an invasive species[edit]

text: Outside its native range, emerald ash borer is an invasive species that is highly destructive to ash trees in its introduced range.[16] Prior to emerald ash borer being found in North America, very little was known about emerald ash borer in its native range aside from a short description of life-history traits and taxonomic descriptions, which resulted in focused research on its biology in North America.[6] Since its accidental introduction into the United States and Canada in the 1990s and its subsequent detection in 2002 in Canton, Michigan, it has since spread other parts of the North America.[17] It is suspected that it was introduced from overseas in shipping materials such as packing crates.[18]

text: Invasiveness and spread[edit]

text: Without factors that would normally suppress emerald ash borer populations in its native range (e.g., resistant trees, predators, and parasitoid wasps), populations can quickly rise to damaging levels.[6] After initial infestation, all ash trees are expected to die in an area within 10 years without control measures.[6] Every North American ash species has susceptibility to emerald ash borer, as North American species planted in China also have high mortality due to infestations, but some Chinese ash species are resistant.[19][20]

text: Green ash and black ash trees are preferred by emerald ash borer. White ash is also killed rapidly, but usually only after all green and black ash trees are eliminated. Blue ash displays some resistance to the emerald ash borer by forming callus tissue around emerald ash borer galleries, but is eventually killed.[21] Many of the specialized predators and parasitoids that suppressed emerald ash borer in Asia were not present in North America. Predators and parasitoids native to North America do not sufficiently suppress emerald ash borer, so populations continue to grow.[6] Emerald ash borer populations can spread between 2.5 to 80 km (1.6 to 49.7 mi) a year.[6] It primarily spreads through flight or by transportation of ash bark containing products such as firewood or nursery stock, which allows it to reach new areas and create satellite populations outside of the main infestation.[6][8]

text: Other factors can limit spread. Winter temperatures of approximately −38 °C (−36 °F) limit range expansion.,[22][23] and overwintering emerald ash borer survive down to average temperatures of −30 °C (−22 °F) due to antifreeze chemicals in the body and insulation provided by tree bark.[8] Larvae can also survive high heat up to 53 °C (127 °F).[8]

text: North American predators and parasitoids can occasionally cause high emerald ash borer mortality, but generally offer only limited control. Mortality due to native woodpeckers is variable. Parasitism by parasitoids such as Atanycolus cappaerti can be high, but overall such control is generally low.[6]

text: Environmental and economic impacts[edit]

text: Emerald ash borer threatens the entire North American Fraxinus genus. It has killed at least tens of millions of ash trees so far and threatens to kill most of the 8.7 billion ash trees throughout North America.[10] Emerald ash borer kills young trees several years before reaching their seeding age of 10 years.[6] In both North America and Europe, the loss of ash from an ecosystem can result in increased numbers of invasive plants, changes in soil nutrients, and effects on species that feed on ash.[8]

text: Damage and efforts to control the spread of emerald ash borer have affected businesses that sell ash trees or wood products, property owners, and local or state governments.[6] Quarantines can limit the transport of ash trees and products, but economic impacts are especially high for urban and residential areas due to treatment or removal costs and decreased land value from dying trees.[24] Costs for managing these trees can fall upon homeowners or local municipalities. For municipalities, removing large numbers of dead or infested trees at once is costly, so slowing down the rate at which trees die through removing known infested trees and treating trees with insecticides can allow local governments more time to plan, remove, and replace trees that would eventually die. This strategy saves money as it would cost $10.7 billion in urban areas of 25 states between 2009–2019, while removing and replacing all ash trees in these same areas at once would cost $25 billion.[24][25] Some urban areas such as Minneapolis, Minnesota, have large amounts of ash with slightly more than 20% of their urban forest as ash.[26]

text: Monitoring[edit]

text: In areas where emerald ash borer has not yet been detected, surveys are used to monitor for new infestations. Visual surveys are used to find ash trees displaying emerald ash borer damage, and traps with colors attractive to emerald ash borer, such as purple or green, are hung in trees as part of a monitoring program.[6] These traps can also have volatile pheromones applied to them that attract primarily males.[7]

text: Sometimes trees are also girdled to act as trap trees to monitor for emerald ash borer. The stressed tree attracts egg-laying females in the spring and trees can be debarked in the fall to search for larvae.[6] If detected, an area is often placed under a quarantine to prevent infested wood material from causing new infestations.[17][6] Further control measures are then taken within the area to slow population growth by reducing beetle numbers, preventing them from reaching reproductive maturity and dispersing, and reducing the abundance of ash trees.[6]

text: Government agencies in both the USA and Canada have utilized a native species of parasitoid wasp, Cerceris fumipennis, as a means of detecting areas to which emerald ash borer has spread. The females of these wasps hunt other jewel beetles and emerald ash borer if it is present. The wasps stun the beetles and carry them back to their burrows in the ground where they are stored until the wasps’ eggs hatch and the wasp larvae feed on the beetles. Volunteers catch the wasps as they return to their burrows carrying the beetles to determine whether emerald ash borer is present. This methodology is known as biological surveillance, as opposed to biological control, because it does not appear that the wasps have a significant negative impact on emerald ash borer populations.[27]

text: Management[edit]

text: In areas where emerald ash borer is non-native and invasive, quarantines, infested tree removal, insecticides, and biological control are used to reduce damage to ash trees.

text: Quarantine and tree removal[edit]

text: Once an infestation is detected, quarantines are typically imposed by state or national government agencies disallowing transport of ash firewood or live plants outside of these areas without permits indicating the material has been inspected or treated (i.e., heat treatment or wood chipping) to ensure no live emerald ash borer are present in the bark and phloem.[17][28] In urban areas, trees are often removed once an infestation is found to reduce emerald ash borer population densities and the likelihood of further spread. Urban ash are typically replaced with non-ash species such as maple, oak, or linden to limit food sources.[29] In rural areas, trees can be harvested for lumber or firewood to reduce ash stand density, but quarantines may apply for this material, especially in areas where the material could be infested.[30]

text: Kentucky Extension specialists suggest selecting uncommon species to replace removed ashes in the landscape.[31] Previous generations created monocultures by planting ash trees in an overabundance, a factor in the extent of the devastation caused by the emerald ash borer. Favoring instead a diversity in species helps keep urban forests healthy. University of Kentucky scientists suggest choosing monotypic species such as the pawpaw, yellowwood, Franklin tree, Kentucky coffeetree, Osage orange, sourwood, and baldcypress.

text: Insecticides[edit]

text: Insecticides with active ingredients such as azadirachtin, imidacloprid, emamectin benzoate, and dinotefuran are currently used since they are systemic (i.e., incorporated into the tree) and remain effective for one to three years depending on the product.[6][32][33] Insecticides are typically only considered a viable option in urban areas with high value trees near an infestation.[32] Ash trees are primarily treated by direct injection into the tree or soil drench. Some insecticides cannot be applied by homeowners and must be applied by licensed applicators. Initially, tree injections do not compromise tree health, but over many years drilling and chemical wounds can compromise the tree's health.[34] Damage from emerald ash borer can continue to increase over time even with insecticide applications.[6] Insecticide treatments are not feasible for large forested areas outside of urban areas.[6]

text: Biological control[edit]

text: The native range of emerald ash borer in Asia was surveyed for parasitoid species that parasitize emerald ash borer and do not attack other insect species in the hope they would suppress populations when released in North America.[35] Three species imported from China were approved for release by the USDA in 2007 and in Canada in 2013: Spathius agrili, Tetrastichus planipennisi, and Oobius agrili, while Spathius galinae was approved for release in 2015.[36][37] Excluding Spathius galinae, which has only recently been released, the other three species have been documented parasitizing emerald ash borer larvae one year after release, indicating that they survived the winter, but establishment varied among species and locations.[37] Tetrastichus planipennisi and Oobius agrili established and have had increasing populations in Michigan since 2008; Spathius agrili has had lower establishment success in North America, which could be due to a lack of available emerald ash borer larvae at the time of adult emergence in spring, limited cold tolerance, and better suitability to regions of North America below the 40th parallel.[37]

text: The USDA is also assessing the application of Beauveria bassiana, an insect fungal pathogen, for controlling emerald ash borer in conjunction with parasitoid wasps.[38]


document_title: Production–possibility frontier

question_text: points outside the production possibilities curve represent combinations of products that are

root

text: Production–possibility frontier

text: Indicators[edit]

text: Efficiency[edit]

text: A PPF (production possibility frontier) typically takes the form of the curve illustrated above. An economy that is operating on the PPF is said to be efficient, meaning that it would be impossible to produce more of one good without decreasing production of the other good. In contrast, if the economy is operating below the curve, it is said to be operating inefficiently because it could reallocate resources in order to produce more of both goods or some resources such as labor or capital are sitting idle and could be fully employed to produce more of both goods.

tag: p

text: For example, if one assumes that the economy's available quantities of factors of production do not change over time and that technological progress does not occur, if the economy is operating on the PPF, production of guns would need to be sacrificed to produce more butter.[1] If production is efficient, the economy can choose between combinations (points) on the PPF: B if guns are of interest, C if more butter is needed, D if an equal mix of butter and guns is required.[1]

text: In the PPF, all points on the curve are points of maximum productive efficiency (no more output of any good can be achieved from the given inputs without sacrificing output of some good); all points inside the frontier (such as A) can be produced but are productively inefficient; all points outside the curve (such as X) cannot be produced with the given, existing resources.[2] Not all points on the curve are Pareto efficient, however; only in the case where the marginal rate of transformation is equal to all consumers' marginal rate of substitution and hence equal to the ratio of prices will it be impossible to find any trade that will make no consumer worse off.[3]

text: Any point that lies either on the production possibilities curve or to the left of it is said to be an attainable point: it can be produced with currently available resources. Points that lie to the right of the production possibilities curve are said to be unattainable because they cannot be produced using currently available resources. Points that lie strictly to the left of the curve are said to be inefficient, because existing resources would allow for production of more of at least one good without sacrificing the production of any other good. An efficient point is one that lies on the production possibilities curve. At any such point, more of one good can be produced only by producing less of the other. [4]

text: Such a two-good world is a theoretical simplification because of the difficulty of graphical analysis of multiple goods. If we are interested in one good, a composite score of the other goods can be generated using different techniques.[5][6] Furthermore, the production model can be generalised using higher-dimensional techniques such as Principal Component Analysis (PCA) and others.[7]

text: Opportunity cost[edit]

text: From a starting point on the frontier, if there is no increase in productive resources, increasing production of a first good entails decreasing production of a second, because resources must be transferred to the first and away from the second. Points along the curve describe the tradeoff between the goods. The sacrifice in the production of the second good is called the opportunity cost (because increasing production of the first good entails losing the opportunity to produce some amount of the second). Opportunity cost is measured in the number of units of the second good forgone for one or more units of the first good.[1]

text: In the context of a PPF, opportunity cost is directly related to the shape of the curve (see below). If the shape of the PPF curve is a straight-line, the opportunity cost is constant as production of different goods is changing. But, opportunity cost usually will vary depending on the start and end points. In the diagram on the right, producing 10 more packets of butter, at a low level of butter production, costs the loss of 5 guns (shown as a movement from A to B). At point C, the economy is already close to its maximum potential butter output. To produce 10 more packets of butter, 50 guns must be sacrificed (as with a movement from C to D). The ratio of gains to losses is determined by the marginal rate of transformation.

text: Marginal rate of transformation[edit]

text: The slope of the production–possibility frontier (PPF) at any given point is called the marginal rate of transformation (MRT). The slope defines the rate at which production of one good can be redirected (by reallocation of productive resources) into production of the other. It is also called the (marginal) "opportunity cost" of a commodity, that is, it is the opportunity cost of X in terms of Y at the margin. It measures how much of good Y is given up for one more unit of good X or vice versa. The shape of a PPF is commonly drawn as concave to the origin to represent increasing opportunity cost with increased output of a good. Thus, MRT increases in absolute size as one moves from the top left of the PPF to the bottom right of the PPF.[8]

text: The marginal rate of transformation can be expressed in terms of either commodity. The marginal opportunity costs of guns in terms of butter is simply the reciprocal of the marginal opportunity cost of butter in terms of guns. If, for example, the (absolute) slope at point BB in the diagram is equal to 2, to produce one more packet of butter, the production of 2 guns must be sacrificed. If at AA, the marginal opportunity cost of butter in terms of guns is equal to 0.25, the sacrifice of one gun could produce four packets of butter, and the opportunity cost of guns in terms of butter is 4.

text: Shape[edit]

text: The production-possibility frontier can be constructed from the contract curve in an Edgeworth production box diagram of factor intensity.[9] The example used above (which demonstrates increasing opportunity costs, with a curve concave to the origin) is the most common form of PPF.[10] It represents a disparity, in the factor intensities and technologies of the two production sectors. That is, as an economy specializes more and more into one product (such as moving from point B to point D), the opportunity cost of producing that product increases, because we are using more and more resources that are less efficient in producing it. With increasing production of butter, workers from the gun industry will move to it. At first, the least qualified (or most general) gun workers will be transferred into making more butter, and moving these workers has little impact on the opportunity cost of increasing butter production: the loss in gun production will be small. However, the cost of producing successive units of butter will increase as resources that are more and more specialized in gun production are moved into the butter industry.[11]

text: If opportunity costs are constant, a straight-line (linear) PPF is produced.[12] This case reflects a situation where resources are not specialised and can be substituted for each other with no added cost.[11] Products requiring similar resources (bread and pastry, for instance) will have an almost straight PPF and so almost constant opportunity costs.[11] More specifically, with constant returns to scale, there are two opportunities for a linear PPF: if there was only one factor of production to consider or if the factor intensity ratios in the two sectors were constant at all points on the production-possibilities curve. With varying returns to scale, however, it may not be entirely linear in either case.[13]

text: With economies of scale, the PPF would curve inward, with the opportunity cost of one good falling as more of it is produced. Specialization in producing successive units of a good determines its opportunity cost (say from mass production methods or specialization of labor).[14]

text: Position[edit]

text: The two main determinants of the position of the PPF at any given time are the state of technology and management expertise (which are reflected in the available production functions) and the available quantities of factors of production (materials, direct labor, and factory overhead).

text: Only points on or within a PPF are actually possible to achieve in the short run. In the long run, if technology improves or if the supply of factors of production increases, the economy's capacity to produce both goods increases; if this potential is realized, economic growth occurs. That increase is shown by a shift of the production-possibility frontier to the right. Conversely, a natural, military or ecological disaster might move the PPF to the left in response to a reduction in an economy's productive capability.[1] Thus all points on or within the curve are part of the production set: combinations of goods that the economy could potentially produce.

text: If the two production goods depicted are capital investment (to increase future production possibilities) and current consumption goods, the higher is investment this year, the more the PPF would shift out in following years.[15] Shifts of the curve can represent how technological progress that favors production possibilities of one good, say guns, more than the other shifts the PPF outwards more along the favored good's axis, "biasing" production possibilities in that direction. Similarly, if one good makes more use of say capital and if capital grows faster than other factors, growth possibilities might be biased in favor of the capital-intensive good.[16][17]

text: Other applications[edit]

text: In microeconomics, the PPF shows the options open to an individual, household, or firm in a two-good world. By definition, each point on the curve is productively efficient, but, given the nature of market demand, some points will be more profitable than others. Equilibrium for a firm will be the combination of outputs on the PPF that is most profitable.[18]

text: From a macroeconomic perspective, the PPF illustrates the production possibilities available to a nation or economy during a given period of time for broad categories of output. It is traditionally used to show the movement between committing all funds to consumption on the y-axis versus investment on the x-axis. However, an economy may achieve productive efficiency without necessarily being allocatively efficient. Market failure (such as imperfect competition or externalities) and some institutions of social decision-making (such as government and tradition) may lead to the wrong combination of goods being produced (hence the wrong mix of resources being allocated between producing the two goods) compared to what consumers would prefer, given what is feasible on the PPF.[19]

text: Notes[edit]

text:
^ Jump up to: a b c d Lipsey, Richard G. An introduction to positive economics (fourth ed.). Weidenfeld & Nicolson. pp. 57–8. ISBN 0-297-76899-9.
Jump up ^ Standish, Barry. Economics: Principles and Practice. South Africa: Pearson Education. pp. 13–15. ISBN 978-1-86891-069-4.
Jump up ^ Varian, Hal (2006). Intermediate Microeconomics (7th ed.). W. W. Norton. pp. 605–606.
Jump up ^ other, Attainable. Principles of Microeconomics. Canada: McGraw-Hill Ryerson Limited. p. 37. ISBN 978-0-07-040144-0.
Jump up ^ Samuelson, Paul A. (1947). Foundations of Economic Analysis. Cambridge, MA: Harvard University Press. ISBN 0-674-31300-3.
Jump up ^ Chacholiades, Miltiades (1986). Microeconomics. New York: Macmillan. p. 97. ISBN 0-02-320560-1.
Jump up ^ Ferguson, C. E. (1972). Microeconomic Theory (3rd ed.). Homewood, Illinois: Richard D. Irwin, Inc. pp. 458–465. ISBN 0-256-02157-0.
Jump up ^ Pindyck, Robert S.; Rubinfeld, Daniel L. (2005). Microeconomics. Pearson Education. ISBN 0-13-713335-9.
Jump up ^ Stolper, Wolfgang F.; Samuelson, Paul A. (1941). "Protection and Real Wages". Review of Economics Studies. The Review of Economic Studies, Vol. 9, No. 1. 9 (1): 58–74. JSTOR 2967638. doi:10.2307/2967638.
Jump up ^ Barthwal, R. R. (2007). Industrial Economics: An Introductory Text Book. p. 31.
^ Jump up to: a b c Anderson, David. Cracking the AP Economics Macro Micro Exam. Princeton Review. pp. 37–8. ISBN 978-0-375-76384-7.
Jump up ^ Hall, Robert Ernest; Lieberman, Marc (2008). Macroeconomics: principles and applications. Mason, OH: Thomson/South-Western. p. 466. ISBN 0-324-42146-X.
Jump up ^ Choi, Eun Kwan; Harrigan, James (2003). Handbook of international trade. Malden, MA: Blackwell Pub. pp. 192–3. ISBN 0-631-21161-6.
Jump up ^ Kemp, Murray C.; Herberg, Horst; Long, Ngo van (1993). Trade, welfare, and economic policies: essays in honor of Murray C. Kemp. Ann Arbor: University of Michigan Press. p. 3. ISBN 0-472-10364-4.
Jump up ^ Samuelson, Paul A., and William D. Nordhaus (2004). Economics. Ch. 1, "Figure 1-5. Investment for Future Consumption Requires Sacrificing Current Consumption."
Jump up ^ Krugman, Paul R. (2004). International economics: theory and policy (sixth ed.). 清华大学出版社. pp. 100–1. ISBN 978-7-302-07889-0.
Jump up ^ Gillespie, Andrew (2007). Foundations of Economics, "The production possibility frontier (curve): the PPF or PPC" (press +). Oxford University Press. Access date 6 January 2010 .
Jump up ^ Coelli, Time; Prasada Rao, D. S.; Battese, George E. (1998). An Introduction to Efficiency and Productivity Analysis. Springer. pp. 59–60. ISBN 978-0-7923-8062-7.
Jump up ^ Farrell, M. J. (1957). "The Measurement of Productive Efficiency". Journal of the Royal Statistical Society. Journal of the Royal Statistical Society. Series A (General), Vol. 120, No. 3. 120 (3): 253–290. JSTOR 2343100.

tag: ol


document_title: 2017–18 UEFA Champions League knockout phase

question_text: when does the champions league quarter finals start

text: Round and draw dates[edit]

text: The schedule of the knockout phase is as follows (all draws are held at the UEFA headquarters in Nyon, Switzerland).[1]

text:
Round
Draw
First leg
Second leg

Round of 16
11 December 2017
13–14 & 20–21 February 2018
6–7 & 13–14 March 2018

Quarter-finals
16 March 2018
3–4 April 2018
10–11 April 2018

Semi-finals
13 April 2018
24–25 April 2018
1–2 May 2018

Final
26 May 2018 at NSC Olimpiyskiy Stadium, Kiev

tag: table

text: Format[edit]

text: The knockout phase involves the 16 teams which qualify as winners and runners-up of each of the eight groups in the group stage.

text: Each tie in the knockout phase, apart from the final, is played over two legs, with each team playing one leg at home. The team that scores more goals on aggregate over the two legs advance to the next round. If the aggregate score is level, the away goals rule is applied, i.e. the team that scored more goals away from home over the two legs advances. If away goals are also equal, then thirty minutes of extra time is played. The away goals rule is again applied after extra time, i.e. if there are goals scored during extra time and the aggregate score is still level, the visiting team advances by virtue of more away goals scored. If no goals are scored during extra time, the tie is decided by penalty shoot-out. In the final, which is played as a single match, if scores are level at the end of normal time, extra time is played, followed by penalty shoot-out if scores remain tied.[2]

text: The mechanism of the draws for each round is as follows:

text:
In the draw for the round of 16, the eight group winners are seeded, and the eight group runners-up are unseeded. The seeded teams are drawn against the unseeded teams, with the seeded teams hosting the second leg. Teams from the same group or the same association cannot be drawn against each other.
In the draws for the quarter-finals onwards, there are no seedings, and teams from the same group or the same association can be drawn against each other.

tag: ul

text: Qualified teams[edit]

text:
Group
Winners
(seeded in round of 16 draw)
Runners-up
(unseeded in round of 16 draw)

A
 Manchester United
 Basel

B
 Paris Saint-Germain
 Bayern Munich

C
 Roma
 Chelsea

D
 Barcelona
 Juventus

E
 Liverpool
 Sevilla

F
 Manchester City
 Shakhtar Donetsk

G
 Beşiktaş
 Porto

H
 Tottenham Hotspur
 Real Madrid

text: Bracket[edit]

text:
Round of 16

Quarter-finals

Semi-finals

Final

  Sevilla
0
2
2

  Manchester United
0
1
1

  Sevilla
1
0
1

  Bayern Munich
2
0
2

  Bayern Munich
5
3
8

  Beşiktaş
0
1
1

  Bayern Munich
1

  Real Madrid
2

  Juventus
2
2
4

  Tottenham Hotspur
2
1
3

  Juventus
0
3
3

  Real Madrid
3
1
4

  Real Madrid
3
2
5

  Paris Saint-Germain
1
1
2

 Winners of semi-final 1

 Winners of semi-final 2

  Porto
0
0
0

  Liverpool
5
0
5

  Liverpool
3
2
5

  Manchester City
0
1
1

  Basel
0
2
2

  Manchester City
4
1
5

  Liverpool
5

  Roma
2

  Chelsea
1
0
1

  Barcelona
1
3
4

  Barcelona
4
0
4

  Roma (a)
1
3
4

  Shakhtar Donetsk
2
0
2

  Roma (a)
1
1
2

text: Round of 16[edit]

text: The draw for the round of 16 was held on 11 December 2017, 12:00 CET.[3]

text: With five English teams in the round of 16, this was the first time five teams from one association qualified for the Champions League knockout phase.[4]

text: Summary[edit]

text: The first legs were played on 13, 14, 20 and 21 February, and the second legs were played on 6, 7, 13 and 14 March 2018.

text:
Team 1
Agg.
Team 2
1st leg
2nd leg

Juventus
4–3
 Tottenham Hotspur
2–2
2–1

Basel
2–5
 Manchester City
0–4
2–1

Porto
0–5
 Liverpool
0–5
0–0

Sevilla
2–1
 Manchester United
0–0
2–1

Real Madrid
5–2
 Paris Saint-Germain
3–1
2–1

Shakhtar Donetsk
2–2 (a)
 Roma
2–1
0–1

Chelsea
1–4
 Barcelona
1–1
0–3

Bayern Munich
8–1
 Beşiktaş
5–0
3–1

text: Matches[edit]

text:
Juventus
2–2
 Tottenham Hotspur

Higuaín  2', 9' (pen.)

Report

Kane  35'
Eriksen  71'

text:
Tottenham Hotspur
1–2
 Juventus

Son Heung-min  39'

Report

Higuaín  64'
Dybala  67'

text: Juventus won 4–3 on aggregate.

text:
Basel
0–4
 Manchester City

Report

Gündoğan  14', 53'
B. Silva  18'
Agüero  23'

text:
Manchester City
1–2
 Basel

Gabriel Jesus  8'

Report

Elyounoussi  17'
Lang  71'

text: Manchester City won 5–2 on aggregate.

text:
Porto
0–5
 Liverpool

Report

Mané  25', 53', 85'
Salah  29'
Firmino  69'

text:
Liverpool
0–0
 Porto

Report

text: Liverpool won 5–0 on aggregate.

text:
Sevilla
0–0
 Manchester United

Report

text:
Manchester United
1–2
 Sevilla

Lukaku  84'

Report

Ben Yedder  74', 78'

text: Sevilla won 2–1 on aggregate.

text:
Real Madrid
3–1
 Paris Saint-Germain

Ronaldo  45' (pen.), 83'
Marcelo  86'

Report

Rabiot  33'

text:
Paris Saint-Germain
1–2
 Real Madrid

Cavani  71'

Report

Ronaldo  51'
Casemiro  80'

text: Real Madrid won 5–2 on aggregate.

text:
Shakhtar Donetsk
2–1
 Roma

Ferreyra  52'
Fred  71'

Report

Ünder  41'

text:
Roma
1–0
 Shakhtar Donetsk

Džeko  52'

Report

text: 2–2 on aggregate. Roma won on away goals.

text:
Chelsea
1–1
 Barcelona

Willian  62'

Report

Messi  75'

text:
Barcelona
3–0
 Chelsea

Messi  3', 63'
Dembélé  20'

Report

text: Barcelona won 4–1 on aggregate.

text:
Bayern Munich
5–0
 Beşiktaş

Müller  43', 66'
Coman  53'
Lewandowski  79', 88'

Report

text:
Beşiktaş
1–3
 Bayern Munich

Vágner Love  59'

Report

Thiago  18'
Gönül  46' (o.g.)
Wagner  84'

text: Bayern Munich won 8–1 on aggregate.

text: Quarter-finals[edit]

text: The draw for the quarter-finals was held on 16 March 2018, 12:00 CET.[21][22]

text: Summary[edit]

text: The first legs were played on 3 and 4 April, and the second legs were played on 10 and 11 April 2018.

text:
Team 1
Agg.
Team 2
1st leg
2nd leg

Barcelona
4–4 (a)
 Roma
4–1
0–3

Sevilla
1–2
 Bayern Munich
1–2
0–0

Juventus
3–4
 Real Madrid
0–3
3–1

Liverpool
5–1
 Manchester City
3–0
2–1

text: Matches[edit]

text:
Barcelona
4–1
 Roma

De Rossi  38' (o.g.)
Manolas  55' (o.g.)
Piqué  59'
L. Suárez  87'

Report

Džeko  80'

text:
Roma
3–0
 Barcelona

Džeko  6'
De Rossi  58' (pen.)
Manolas  82'

Report

text: 4–4 on aggregate. Roma won on away goals.

text:
Sevilla
1–2
 Bayern Munich

Sarabia  31'

Report

Navas  37' (o.g.)
Thiago  68'

text:
Bayern Munich
0–0
 Sevilla

Report

text: Bayern Munich won 2–1 on aggregate.

text:
Juventus
0–3
 Real Madrid

Report

Ronaldo  3', 64'
Marcelo  72'

text:
Real Madrid
1–3
 Juventus

Ronaldo  90+8' (pen.)

Report

Mandžukić  2', 37'
Matuidi  61'

text: Real Madrid won 4–3 on aggregate.

text:
Liverpool
3–0
 Manchester City

Salah  12'
Oxlade-Chamberlain  21'
Mané  31'

Report

text:
Manchester City
1–2
 Liverpool

Gabriel Jesus  2'

Report

Salah  56'
Firmino  77'

text: Liverpool won 5–1 on aggregate.

text: Semi-finals[edit]

text: The draw for the semi-finals was held on 13 April 2018, 13:00 CEST.[31]

text: For the first time since the 2009–10 UEFA Champions League, all the four teams at this stage represent different national associations.[32]

text: Summary[edit]

text: The first legs were played on 24 and 25 April, and the second legs will be played on 1 and 2 May 2018.

text:
Team 1
Agg.
Team 2
1st leg
2nd leg

Bayern Munich

 Real Madrid
1–2
1 May

Liverpool

 Roma
5–2
2 May

text: Matches[edit]

text:
Bayern Munich
1–2
 Real Madrid

Kimmich  28'

Report

Marcelo  44'
Asensio  57'

text:
Real Madrid
v
 Bayern Munich

Report

text:
Liverpool
5–2
 Roma

Salah  36', 45+1'
Mané  56'
Firmino  61', 69'

Report

Džeko  81'
Perotti  85' (pen.)

text:
Roma
v
 Liverpool

Report

text: Final[edit]

text: The final will be played at the NSC Olimpiyskiy Stadium in Kiev on 26 May 2018. The "home" team (for administrative purposes) was determined by an additional draw held after the semi-final draw.[31]

text:
Winners of semi-final 1
v
 Winners of semi-final 2

Report

text: Notes[edit]

text: Jump up ^ Shakhtar Donetsk played their home match at Metalist Stadium, Kharkiv, instead of their regular stadium Donbass Arena, Donetsk, due to the war conditions in Eastern Ukraine.


document_title: The Flash (season 4)

question_text: when will the flash season 4 episode 17 come out

text: The Flash (season 4)

text: Episodes[edit]

text:
No.
overall
No. in
season
Title
Directed by
Written by
Original air date
Prod.
code
U.S. viewers
(millions)

70
1
"The Flash Reborn"
Glen Winter
Story by : Andrew Kreisberg
Teleplay by : Todd Helbing & Eric Wallace
October 10, 2017 (2017-10-10)
T27.13401
2.84[2]

Iris has been aiding Team Flash in Central City for six months, but refuses to grieve Barry. A flying samurai with superpowers appears in Central City, threatening to destroy the city if the real Flash does not face him. Cisco reveals he has formulated a way to bring back Barry without destabilizing the Speed Force and tracks down Caitlin for help, but is forbidden by Iris to bring Barry back. Against Iris' orders, Team Flash successfully returns Barry, who rambles random statements and continually writes symbols on the walls. Wally engages the samurai, but is defeated. Cisco deciphers Barry's writings and finds an apparently meaningless sentence. In an attempt to recover Barry's memories, Iris gives herself up to the samurai. The plan works and Barry speeds away, rescuing Iris and defeating the samurai, who is revealed to be an android. Caitlin rejoins Team Flash, but is revealed to have been working for a mobster called Amunet, while also continuing to prevent the Killer Frost personality from emerging. The "Samuroid" is revealed to have been controlled by the Thinker, whose plan was to draw out the Flash for his next schemes.

71
2
"Mixed Signals"
Alexandra La Roche
Jonathan Butler & Gabriel Garza
October 17, 2017 (2017-10-17)
T27.13402
2.54[3]

When Barry, Joe, and Cisco report to a crime scene, they discover remnants of a mysterious code. Cisco presents Barry with a technologically advanced suit, intended to facilitate his activities. He tests it out, trying to save someone from a haywire car controlled by metahuman Ramsey Deacon. Gypsy arrives on Earth-1 for a date with Cisco, who is forced to cancel it so as to focus on Deacon. Acting on a suggestion from Caitlin, Iris signs her and Barry up for couples therapy to sort out their relationship. Deacon kidnaps a witness, a former member of a tech team that stole his idea for profit. Barry and Wally go to save him, but Deacon uses his abilities to send Barry's suit haywire. On Iris' instruction, Barry throws lightning at himself, shorting out his suit. He then incapacitates Deacon, who is locked up in the meta wing of Iron Heights, revealed to be part of the Thinker's plan. Cisco finally goes out with Gypsy. Wondering how Deacon gained his powers being absent during the particle accelerator incident, Barry and Joe learn from Deacon that there are "others."

72
3
"Luck Be a Lady"
Armen V. Kevorkian
Sam Chalsen & Judalina Neira
October 24, 2017 (2017-10-24)
T27.13403
2.62[4]

In flashbacks, the Thinker observes Becky Sharpe, a woman with seemingly unending bad luck, and determines that she will be easily manipulated. In the present, Becky robs a bank and gets away when Barry slips on marbles. Harry arrives from Earth-2 and tells Wally that Jesse has decided to break up with him in order to focus on her vigilantism. Cisco deduces that Becky is a metahuman with the power of favorable luck while inducing misfortune to others. Barry realizes that the portal he used to escape the Speed Force exposed an entire busload of people, including Becky and Deacon, to transformative dark matter. Harry informs Cisco that Jesse has expelled him from her crime-fighting team due to his attitude. Becky's powers expand out of control, reactivating the particle accelerator, which Harry deliberately allows, nullifying Becky's powers and leading to her incarceration. Cisco and Harry identify twelve new metahumans created on the bus and the latter suspects that an unknown party has manipulated the events surrounding Barry's return. Wally decides to leave on a journey to find himself. The Thinker is revealed to be spying on S.T.A.R. Labs through the "Samuroid" helmet. Joe learns Cecile is pregnant.

73
4
"Elongated Journey Into Night"
Tom Cavanagh
Sterling Gates & Thomas Pound
October 31, 2017 (2017-10-31)
T27.13404
1.99[5]

Gypsy's father, Breacher, attacks Cisco, vowing to hunt and kill him in 24 hours, allowing the romance should he survive. Team Flash learns that the bus driver was murdered and tracks down another passenger, Ralph Dibny, former corrupt CCPD detective exposed by Barry and currently an infamous private investigator. As two thugs attack Dibny, he is revealed to have the power to stretch. Caitlin stabilizes his powers with a serum. The team learns that Ralph has been blackmailing Mayor Bellows for adultery, with the latter revealed to have hired the thugs. Barry confronts Ralph for his actions while the latter scolds him, claiming to have been a "good cop". He later stops blackmailing Bellows, who still attempts to kill him while Breacher mistakes the former for a Plastoid, the species that invaded Earth-19 previously, and attacks him. Cisco intervenes and saves Ralph, whom Barry, having revealed his alter-ego, convinces to help arrest an escaping Bellows. Admiring Cisco's gallantry, Breacher allows the relationship. Barry recruits Ralph for Team Flash and learns that someone named DeVoe instructed Ralph to watch Bellows. Barry remembers that Abra Kadabra and Savitar both mentioned DeVoe. Meanwhile, Caitlin finds a message on her apartment door.

74
5
"Girls Night Out"
Laura Belsey
Lauren Certo & Kristen Kim
November 7, 2017 (2017-11-07)
T27.13405
2.38[6]

While failing to track DeVoe, Team Flash is visited by Felicity, who joins Iris's bachelorette party. Mocking Cisco's plans for Barry's bachelor party, Ralph takes the men to a strip club, where they learn that Cecile's daughter, Joanie, is working. Joe confronts her, who states she is only doing feminist research. Ralph incites a brawl, leading to the men's arrest until Harry posts bail. Meanwhile, Amunet's enforcer, Norvock, demands Caitlin's return and attacks the women when she refuses. Killer Frost emerges and repels him, later telling Iris that Caitlin accepted Amunet's employment in exchange for the means to control Frost. Learning that Amunet is holding a metahuman she calls "the Weeper", whose tears are a strong narcotic, prisoner and intends to sell him, Iris's party decides to stop her. Though Caitlin refuses to join, she attacks Amunet when seeing her friends in danger. Using a strong magnet, the team robs Amunet's metal shards, leaving her powerless. Iris dissuades Frost from killing Amunet, who promises revenge. Both parties refuse to tell each other about their adventures. Iris asks Caitlin to be her maid of honor while Joe convinces Joanie to tell Cecile about her research. DeVoe captures the Weeper.

75
6
"When Harry Met Harry..."
Brent Crowell
Jonathan Butler & Gabriel Garza
November 14, 2017 (2017-11-14)
T27.13406
2.46[7]

Barry trains Ralph to use his abilities, with Cisco making a stretchable suit for him. Another bus metahuman, a Lakota Sioux Native named Mina Chayton, who can animate statues, starts attacking Central City & stealing pieces of a Black Bison necklace, which she claims belongs to her tribe. When Barry and Ralph catch up to her, she attacks Barry with a caveman statue and attempts a getaway. Ralph chooses to stop her, but a little girl is injured in the process. Ralph regrets his actions, but is comforted by Barry. Chayton escapes CCPD, going after the last necklace piece held at the museum. When Barry and Ralph confront her, she brings a dinosaur skeleton to life. Barry arrests Chayton while Ralph saves a security guard from the skeleton. Later, Ralph reveals he mailed the necklace back to Chayton's tribe, before visiting the little girl in the hospital, using his abilities to entertain her. Meanwhile, Harry, trying to make friends, works with his doppelgangers of alternate Earths, The Council of Wells. They figure out that DeVoe is a man named Clifford DeVoe. Barry and Joe head to DeVoe's house, to find out that he is a middle-aged man in a wheelchair.

76
7
"Therefore I Am"
David McWhirter
Eric Wallace & Thomas Pound
November 21, 2017 (2017-11-21)
T27.13407
2.20[8]

Barry and Joe interrogate DeVoe and his wife to try and get more information. In flashbacks, DeVoe and his wife build a thinking cap to improve his brain capacity, powering it through the particle accelerator explosion. DeVoe's increased brain power accelerates his amyotrophic lateral sclerosis, forcing his wife to build him a special chair to keep him alive. Barry discovers the camera in the Samuroid head and goes to DeVoe's house, narrowly avoiding being caught by DeVoe's wife. Barry later confronts DeVoe, who reveals his true identity, leading to Cisco dubbing him "The Thinker". Wally returns to Team Flash from Blue Valley.

77
8
"Crisis on Earth-X, Part 3"
Dermott Downs
Story by : Andrew Kreisberg & Marc Guggenheim
Teleplay by : Todd Helbing
November 28, 2017 (2017-11-28)
T27.13408
2.82[9]

Barry, Oliver, Sara, Alex, Martin and Jax wake up in a Nazi concentration camp on Earth-X wearing power dampeners. The arriving SS Sturmbannführer is revealed to be the Earth-X doppelgänger of Quentin Lance, who plans to execute them, but they are saved by Citizen Cold (the Earth-X doppelgänger of Leonard Snart) and Ray Terrill. Snart and Terrill take them to the headquarters of the Freedom Fighters, where the team meets the resistance movement's leader, General Schott (Winn Schott's Earth-X doppelgänger). They learn that the only way back to Earth-1 is through a temporal gateway in a research facility, which Schott plans to blow up to strand Dark Arrow (Oliver's Earth-X doppelgänger) on Earth-1. Oliver disguises himself as Dark Arrow to infiltrate the facility and discovers the Nazi doomsday device against parallel Earths is a militarized timeship called Wellenreiter. Barry and Ray battle the Freedom Fighters' Red Tornado to stop it from destroying the gateway while the rest of the team enters the facility to reactivate its portal, during which Stein is shot and gravely wounded. On Earth-1, Eobard Thawne prepares to perform surgery on Kara to save Overgirl. Felicity and Iris try to stop him, but are captured.

This episode continues a crossover event that begins on Supergirl season 3 episode 8 and Arrow season 6 episode 8, and concludes on Legends of Tomorrow season 3 episode 8.

78
9
"Don't Run"
Stefan Pleszczynski
Sam Chalsen & Judalina Neira
December 5, 2017 (2017-12-05)
T27.13409
2.22[10]

While out Christmas shopping, Barry is ambushed and kidnapped by DeVoe while Caitlin is kidnapped from Jitters by Amunet. Iris claims they have to look for both of them, despite Harry's claim that they have insufficient time and resources and that they can only afford to search for one. Barry is held in DeVoe's lair. Caitlin is forced by Amunet to perform surgery on a metahuman named Dominic Lanse, who can read minds. They try to escape, but Amunet blocks their exit. Caitlin manages to briefly incapacitate Amunet, and she and Dominic flee the building they are being held in. Once outside, they are rescued by Cisco and Ralph, as Iris has chosen to focus on finding Caitlin. Barry manages to escape from DeVoe. Team Flash celebrates Christmas at the West house and Dominic joins them. Barry gets a security alert from his apartment. When he arrives, he receives a phone call from Dominic, who reveals that Amunet re-kidnapped Dominic and DeVoe has transferred his consciousness into Dominic's body. Barry discovers DeVoe's original body dead on his apartment floor and he realizes DeVoe has framed him for his "murder"; the police arrive, and Barry lets himself get arrested, not wanting to leave Iris again.

79
10
"The Trial of The Flash"
Philip Chipera
Lauren Certo & Kristen Kim
January 16, 2018 (2018-01-16)
T27.13410
2.51[11]

Barry stands trial for the murder of Clifford DeVoe, with Cecile representing him. Cisco and Joe have to leave during the trial for a meta investigation, in which a meta caused people to collapse. Singh reveals to Joe he is appearing as a witness for the prosecution against Barry. The meta is eventually discovered as Neil Borman, who is a meta who produces radiation, which is causing the illness and collapsing. Barry takes him on, but is ill equipped to deal with the situation. Cisco and Killer Frost travel to the scene where Caitlin tries to freeze Borman, who quickly defrosts and incapacitates Caitlin. Barry creates a vacuum seal around Borman to contain the radiation, with Cisco transporting the radiation to the dead Earth-15, draining the meta and defeating him. Barry is eventually found guilty by the jury and is sentenced to life in prison.

80
11
"The Elongated Knight Rises"
Alexandra La Roche
Sterling Gates & Thomas Pound
January 23, 2018 (2018-01-23)
T27.13411
2.12[12]

Barry uses his speed to secretly help the guards contain the other inmates during a prison riot. He also befriends Dave Ratchet, his father's former cellmate. The next day, Barry meets Axel Walker who was later broken out of prison by his mother Zoey Clark, his father's one-time partner Prank. Axel challenges Ralph by threatening to cause chaos in the city. Ralph attempts to stop him but is wounded by Axel and is evacuated by Cisco. Ralph sneaks into the prison to talk to Barry about how scared he is. Barry reassures him that being a hero isn't about not being scared, but about having the ability to rise above your fear. Cisco and Caitlin go to rescue the hostages, but get captured by Axel and Zoey, who intend to kill them. Ralph arrives, and attempts to shield the two from an acid shower, until Wells manages to hack into the shower system to neutralize its acidity. Iris visits Barry in prison, where they reaffirm their love for each other. Ralph and Cisco go to get coffee, where they meet the excitable girl from the wedding. The girl writes in her journal, where she appears to be writing in the language Barry was using when he came out of the Speed Force.

81
12
"Honey, I Shrunk Team Flash"
Chris Peppe
Sam Chalsen & Judalina Neira
January 30, 2018 (2018-01-30)
T27.13412
2.60[13]

Cecile develops telepathic abilities as a result of her pregnancy, combined with dormant dark matter in her cells, which Caitlin assures her should be temporary. In prison, Barry learns that Ratchet is innocent of a robbery-homicide that was actually committed by Sylbert Rundine fifteen years prior. Barry asks the team to look into the case. Rundine turns out to be a bus meta with the ability to shrink and enlarge objects, and he shrinks Cisco and Ralph while escaping. Harry's attempted cure backfires, and Caitlin determines that if they are not re-enlarged within a certain period of time, their bodies will explode. The team confronts Rundine at a warehouse, where Harry tricks him into re-enlarging Ralph and Cisco. Rundine is arrested, but refuses to confess to the earlier crime. Barry gathers that even if Ratchet went free, he would be as unhappy in the city as he is in prison; he wishes to live in a secluded Chinese village called Jiaju, but fears he will never get there. Barry then uses his speed to take Ratchet to Jiaju, where he can live out his dream. After discovering Barry is the Flash, the prison's warden, Gregory Wolfe, locks Barry in his private metahuman wing, intending to sell him to Amunet.

82
13
"True Colors"
Tara Nicole Weyr
Jonathan Butler & Gabriel Garza
February 6, 2018 (2018-02-06)
T27.13413
2.28[14]

Wolfe plans to sell Barry and the imprisoned bus metas (Ramsey Deacon, Becky Sharpe, Mina Chaytan, and Sylbert Rundine) to Amunet, so they plan to escape. Cecile discovers Wolfe's plans after reading his mind. Ralph encounters a former colleague and his negative interaction with him prompts the discovery that he can shapeshift. His lack of mastery of the new ability prevents his attempt to foil Amunet's deal with Wolfe. Barry helps the metas escape the power dampeners, but they are cornered by Wolfe and Amunet. DeVoe arrives and again uses his chair to extract the metas' abilities, before transferring his mind into Sharpe's body. He then crushes Wolfe's skull as Marlize looks on in horror; Amunet flees. Ralph uses his shapeshifting ability to appear as the original DeVoe at Barry's appeal, claiming that he was unconscious at Barry's loft but not dead, which clears Barry's name. Team Flash realizes that DeVoe is only stealing powers from metahumans who were on the bus when the dark matter wave was unleashed, which means he will likely target Ralph as well. Back at the DeVoes' house, their marriage continues to deteriorate, and DeVoe drugs his wife with the Weeper's tears to maintain her devotion towards him.

83
14
"Subject 9"
Ralph Hemecker
Mike Alber & Gabe Snyder
February 27, 2018 (2018-02-27)
T27.13414
2.12[15]

Barry is put on indefinite leave at the CCPD due to his connection with the DeVoe case. The team encounter another bus metahuman named Izzy with sound wave abilities, amplified by her violin. She manages to use her abilities when DeVoe (inside Sharpe's body) comes to claim her. Barry and Ralph help to train Izzy to refine her abilities, which proves difficult when she gets hurt. Eventually DeVoe shows up once again, using Dominic's and Becky's abilities to make Barry experience a brain aneurysm, while using Rundine's abilities to incapacitate Ralph. DeVoe then once again uses the chair to transfer his mind into Izzy's body and escapes. Both Ralph and Barry comfort each other over their respective losses: Barry being let go from the police force and Ralph losing Izzy to DeVoe. These losses enforce both Barry's and Ralph's determination to bring DeVoe down and save the three remaining metas.

84
15
"Enter Flashtime"
Gregory Smith
Todd Helbing & Sterling Gates
March 6, 2018 (2018-03-06)
T27.13415
2.04[16]

Jesse comes to Earth-1 to have a talk with her dad. Eco-terrorist Veronica Dale sets off a nuclear bomb, which Barry tries to stop, entering a form of superspeed known as Flashtime, where everything is frozen. However, the bomb has already detonated, and he and Jesse cannot stop it or save everyone with superspeed. Jay Garrick comes from Earth-3 to help, but they are still unable to stop it. Barry remains in Flashtime for hours, bringing each of his friends into it, in an attempt to find a solution; they discuss options such as freezing it or sending it to another Earth, but none of those solutions prove to be viable. Eventually, Iris gives him the idea to retrieve the Quark Sphere from the Speed Force to send a blast lightning through the bomb, enough to disable it. Barry does so, and throws the Sphere back into the Speed Force, saving Central City. Jay admits he is retiring and going to train a new "female" speedster. Jesse and Jay return to their Earths, and Caitlin and Wells go for a coffee, where they encounter the mysterious girl.

85
16
"Run, Iris, Run"
Harry Jierjian
Eric Wallace
March 13, 2018 (2018-03-13)
T27.13416
2.09[17]

A metahuman with fire powers tries to rob Central City bank. Another bus meta named Matthew Kim touches the metahuman, which causes his powers to transfer to another individual. When Joe, Iris and Barry turn up to ask Kim a few questions, Barry and Iris come into contact with Kim, causing Barry to lose his speed and Iris to gain superspeed. Inspired by Thawne, Harry plans to build his own thinking cap to outwit DeVoe. With their roles reversed, Iris becomes Central City's hero speedster, while Barry must learn to act as team leader. The new metahuman demands money and terrorizes the city with his fire powers. Using Wells' thinking cap, the Team comes up with the idea for Iris to create a tidal wave, negating the flames and defeating the meta. Back at S.T.A.R. Labs, Kim touches Iris and Barry again, restoring the Flash's speed. At home, Iris admits that while she did enjoy having superspeed, Central City needs the light that Barry was, and she is happy being team leader. Wells uses his thinking cap once more, determining the final two bus metas are Janet Petty and Edwin Gauss.

86
17
"Null and Annoyed"
Kevin Smith
Lauren Certo & Kristen Kim
April 10, 2018 (2018-04-10)
T27.13417
1.82[18]

Barry and Ralph train to defeat DeVoe, with Barry becoming annoyed at Ralph's apparent inability to be serious. The team manages to locate another bus meta, Janet Petty. When Barry and Ralph confront her, it is revealed that Petty can manipulate a person's gravitational pull, which she demonstrates on Barry. Fearing once again that Ralph is not taking things seriously, Barry refuses to work with him. Ralph reveals his comedic attitude is due to a difficult childhood where his father abandoned him, causing him to make jokes whenever he is scared or under pressure. Barry relents and they go to stop Janet at a gala event. Janet uses her powers on Barry, causing him to float into the atmosphere. Barry tells the team to trust Ralph to improvise. Ralph detains Janet, then becomes a giant airbag to allow Barry to land safely. DeVoe's wife discovers he has been drugging her, so she will continue to assist him. Breacher comes to Earth-1 to ask Cisco for help as some of his powers have failed. Harry takes the thinking cap to Thawne's time vault to recharge it and activates Gideon.

87
18
"Lose Yourself"
Hanelle Culpepper
Jonathan Butler & Gabriel Garza
April 17, 2018 (2018-04-17)
T27.13418
1.88[19]

Team Flash track down the final bus meta Edwin Gauss, but are followed by the Samuroid, who injures Caitlin. The team rush back to Star Labs to regroup and heal. Caitlin reveals to Iris that Killer Frost is activated by her adrenal gland, and she is working on a way to separate them. Harry comes up with a tuning fork weapon that mimics Izzy's abilities in order to defeat DeVoe. Ralph reveals to Barry that he isn't afraid of losing his own life, but of Team Flash losing theirs, as he considers them family. Wells is shown to be addicted to the Thinking Cap, which Joe helps him deal with. Ralph takes the fork, with the intent to go with Edwin to kill DeVoe, which Barry argues against. Eventually, DeVoe manages to take over Edwin's mind, and as well takes the abilities of Janet Petty and Matthew Kim, before transferring his mind into Ralph's body. The team try to stop him, but DeVoe incapacitates them, and alters Caitlin's DNA, removing the dark matter and Killer Frost, before leaving. Back at his lair, DeVoe uses Ralph's morphing abilities to morph back into his original form, while he and Marlize plan their next move to destroy Team Flash.

88
19
"Fury Rogue"
Rachel Talalay
Joshua V. Gilbert & Jeff Hersh
April 24, 2018 (2018-04-24)
TBA
1.90[20]

With DeVoe moving forwards with his plans, Team Flash decide to secure Neil Borman. Barry and Cisco travel to Earth X to recruit Leo Snart as a backup, but are followed to Earth 1 by the Earth X doppelganger of Laurel Lance. Team Flash plan to deliver Borman to a safe ARGUS facility, using a suit to contain the radiation, with Snart on hand, in case Borman goes nuclear. Snart agrees to help, but claims he can only stay for 24 hours, as he is due to get married to Ray Terrill. DeVoe attempts to intercept the transfer, but he and Team Flash are further ambushed by Earth X Laurel, who kidnaps Caitlin, Borman and Joe, holding them at CCPD. Snart learns about Ralph, and convinces Barry to allow himself to grieve his fallen allies, which Barry eventually does, giving him strength to defeat Laurel. Lyla transfers Borman to another facility and Leo returns to Earth X. Cisco and Wells come up with a plan to boost Wells' thinking cap. Devoe goes more into his "god-complex"; stating that human emotion is a weakness, causing Marlize to doubt him.

89
20
"Therefore She Is"[21]
Rob J. Greenlea
Sterling Gates & Thomas Pound
May 1, 2018 (2018-05-01)
TBA
TBD

90
21
"Harry and the Harrisons"[22]
Kevin Mock
Judalina Neira & Lauren Certo
May 8, 2018 (2018-05-08)
TBA
TBD

91
22
"Think Fast"[23]
Viet Nguyen
Sam Chalsen & Kristen Kim
May 15, 2018 (2018-05-15)
TBA
TBD

92
23
"We Are the Flash"[24]
TBA
TBA
May 22, 2018 (2018-05-22)[25]
TBA
TBD

text: Cast and characters[edit]

text: Main[edit]

text:
Grant Gustin as Barry Allen / Flash[26]
Candice Patton as Iris West[26]
Danielle Panabaker as Caitlin Snow / Killer Frost[27]
Carlos Valdes as Cisco Ramon / Vibe[26]
Keiynan Lonsdale as Wally West / Kid Flash[26]
Neil Sandilands as Clifford DeVoe / Thinker[28]
Tom Cavanagh as Harrison "Harry" Wells[26]
Jesse L. Martin as Joe West[26]

text: Recurring[edit]

text:
Danielle Nicolet as Cecile Horton[29]
Kim Engelbrecht as Marlize DeVoe / Mechanic[28]
Jessica Camacho as Cynthia / Gypsy[30][31]
Patrick Sabongui as David Singh[32]
Donna Pescow as Sharon Finkel
Richard Brooks as Gregory Wolfe[33]
Hartley Sawyer as Ralph Dibny / Elongated Man[34]
Katee Sackhoff as Amunet Black / Blacksmith[35]
Sugar Lyn Beard as Rebecca Sharpe / Hazard[36] and Clifford DeVoe / Thinker

text: Guest[edit]

text:
Britne Oldford as Shawna Baez / Peek-a-Boo[37]
Mark Sweatman as Norvok[38]
Dominic Burgess as Ramsey Deacon / Kilg%re[39]
Chelsea Kurtz as Mina Chayton / Black Bison[40]
Violett Beane as Jesse Chambers Wells / Jesse Quick[41]
Danny Trejo as Josh / Breacher[28][31]
Vito D'Ambrosio as Anthony Bellows
Emily Bett Rickards as Felicity Smoak[35]
Riley Jade Berglund as Joanie[42]
Matt Afonso as Weeper[43]
Stephen Amell as Oliver Queen / Green Arrow and Dark Arrow[44]
Victor Garber as Martin Stein / Firestorm[44]
Caity Lotz as Sara Lance / White Canary[44]
Chyler Leigh as Alex Danvers[44]
Franz Drameh as Jefferson Jackson / Firestorm[44]
Paul Blackthorne as Quentin Lance / Sturmbannführer
Jeremy Jordan as General Schott[44]
Juliana Harkavy as Dinah Drake / Black Canary
Melissa Benoist as Kara Zor-El / Kara Danvers / Supergirl and Overgirl[44]
Wentworth Miller as Leonard Snart / Citizen Cold[45]
Russell Tovey as Ray Terrill / The Ray[44]
Frederick Schmidt voices Metallo-X
Kendrick Sampson as Dominic Lanse / Brainstorm[46] and Clifford DeVoe / Thinker
Mark Valley as Anton Slater[47]
Ryan Alexander McDonald as Neil Borman / Fallout
Devon Graye as Axel Walker / Trickster[48]
Corinne Bohrer as Zoey Clark / Prank[48]
Bill Goldberg as Dave Ratchet / Big Sir[48]
Derek Mears as Sylbert Rundine / Dwarfstar[49]
Paul McGillion as Earl Cox
Miranda MacDougall as Izzy Bowin / Fiddler[50] and Clifford DeVoe / Thinker
John Wesley Shipp as Jay Garrick[51]
Leonardo Nam as Matthew Kim / Melting Point[52]
Max Adler as Jaco Birch / Pyro[53]
Bethany Brown as Janet Petty / Null
Arturo Del Puerto as Edwin Gauss / Folded Man
Katie Cassidy as Siren-X
David Ramsey as John Diggle / Spartan
Anne Dudek as Tracy Brand[54]
Victoria Askounis as young Caitlin Snow[55]

text: Production[edit]

text: Development[edit]

text: The series was renewed for a fourth season on January 8, 2017,[56] earlier than usual for the series. Executive producer Andrew Kreisberg said on this, "The great thing about our dear friends at The CW and Mark Pedowitz picking the shows up as early as they did has allowed us to start building the schedules for next season."[57] In May 2017, it was announced that Aaron Helbing would not return as an executive producer for season four, with only Greg Berlanti, Andrew Kreisberg, Sarah Schechter, and Todd Helbing returning from previous seasons.[58] Todd Helbing and Kreisberg were slated to serve as the season's showrunners.[59][60] In November 2017, Kreisberg was suspended from his role as executive producer and showrunner on The Flash over allegations of sexual harassment.[61][62] By the end of the month, he had been fired, with his name eventually being removed from the credits from all shows he worked on. In addition, Berlanti would take additional responsibilities working with Helbing to co-showrun the season.[63]

text: Writing[edit]

text:
The way I see it is, time is non-linear and everything is happening at once in the Speed Force. In some ways he's had an awakening and he's had a rebirth. Our first episode is called 'Reborn,' and it is a rebirth for Barry, but he's kind of scrambled, too, because he's experienced so much so quick over the course of six months, even though for him it was an eternity. He's not Barry when we see him for the first time.

—Grant Gustin on the rebirth of Barry in season four.[64]

tag: div

text: In March 2017, Kreisberg confirmed that the main villain for the fourth season would not be a speedster, like the previous three seasons.[65] Executive producers Aaron and Todd Helbing also mentioned that there would be less time travel in the season, with Aaron saying, "We like playing with the timelines and the different time periods and future and past. For now, I think we're going to focus on the present."[66] In June 2017, Clifford DeVoe / Thinker was reported to be the main antagonist of the season. He was first hinted in the third season episode "Abra Kadabra" when the titular villain mentions him among the Flash's greatest enemies, and again in the season finale "Finish Line" when Savitar mentions facing DeVoe but states that the Flash has not dealt with him yet.[67] At the series' San Diego Comic-Con panel, the speculation was confirmed, with Todd Helbing saying, "With three Speedsters in a row, this year it's the fastest man alive against the fastest mind alive."[29] He added that the writers were "making a conscious effort this year to get the fun quotient back up".[68]

text: Regarding the possibility of Wally West taking on the mantle of the Flash in Barry's absence, Keiynan Lonsdale said that "It's not something that's on my radar. I feel as though there is so much story to tell and Wally has so much growing to do... We need to see how these character realistically get to where they are headed for."[69] With the action picking up six months after season three, Kid Flash and Vibe are left to protect Central City, with Carlos Valdes saying "the team is sort of clutching at straws to keep the city together,... there is a unanimous feeling amongst the remaining members that it's just not the same without Barry... So in light of that, Cisco does whatever it takes to get his friends back."[70] Valdes also confirmed the return of Cisco's more lighthearted joking manner.[70] Candice Patton explained Iris West's larger role within Team Flash as "a way of distracting herself,"[70] adding that "[Iris] is forced to deal with that anger and resentment and abandonment by kind of focusing on protecting Central City... We're seeing a very different Iris, almost a very hardened Iris."[71] Kreisberg also hinted at some major growth for Iris this season, and noted that "the season premiere is all about Iris and Cisco, not Barry".[72]

text: In July 2017, Sterling Gates, DC Comics comic book writer, joined as a member of the fourth season's writing staff.[73] At the Television Critics Association press tour in August 2017, Pedowitz stated that the fourth season of The Flash is "going to try to find the lightness... of the Barry Allen of the first two seasons,"[74] and said that the show was likely "done with Speedster villains".[75] Later in the month, Kreisberg confirmed the return of Harry Wells from Earth-2, saying that "season 4 for Harry is really realizing what he's missing in his life and what it is he needs to become a better, more complete person, and so he's going to be going on a fairly epic emotional journey this season that is tied to the Thinker's plan," in addition to confirming the introduction of a new version of the Wells character.[76]

text: In September 2017, Helbing noted "There's a lot of love in the air this season," and compared Barry and Iris' reunion to "somebody going off to war for six months and coming back. There's a lot that Iris experienced that Barry didn't when he was gone, and it's really [about] the fun and the emotional component of making up that time when they weren't together." Helbing also explained that the Speed Force "let [Barry] deal with all of the baggage [from the past three seasons]. When he comes out, he's sort of left that all behind."[77] That month, Kreisberg also confirmed that Barry and Iris will be getting married this season,[78] while also revealing that the pair will be going to couples therapy since "[they] keep comically clashing inadvertently because [both are] used to being in charge, and so they wind up going... to work through it." He added, "The two of them with the therapist is some of the funniest stuff we have ever done on this show, but it also leads to a deepening of their relationship."[79]

text: Casting[edit]

text: Main cast members Grant Gustin, Candice Patton, Danielle Panabaker, Carlos Valdes, Keiynan Lonsdale, Tom Cavanagh, and Jesse L. Martin return from previous seasons as Barry Allen / The Flash, Iris West, Caitlin Snow / Killer Frost, Cisco Ramon / Vibe, Wally West / Kid Flash, Harrison Wells, and Joe West, respectively.[26] Cavanagh will portray Harry Wells from Earth-2 at the start of the season, without ruling out the possibility of introducing another incarnation of the Wells character later on.[70] Teasing the arrival of a new Harrison Wells, Cavanagh said, "We're going to start with Harry and then find a way, I think, to try and get a different version of Wells in there, be it some version of Harry or whatnot as the season's gaps present themselves."[80] Also returning from earlier in the series are Jessica Camacho as Gypsy,[30] and Anne Dudek as Tracy Brand.[54] It was revealed that Tom Felton, who joined the cast as Julian Albert in the third season, would not be a series regular in the fourth season, and that there were no plans for him to appear.[81] Julian's absence will be addressed "pretty quickly — there's a reason why he's no longer with the team," said Helbing.[82] In the season premiere, it is revealed that Julian has returned to London.[83] Kreisberg also confirmed that he had put on hold the planned return of Violett Beane as Jesse Quick due to the high number of speedsters on the show, but did not rule out a possible return in the future.[84] Beane eventually appeared as Jesse on the episode "Luck Be a Lady".[41] Britne Oldford, who previously appeared as Shawna Baez / Peek-a-Boo in the first season and the web series The Chronicles of Cisco, reprised her role in the season premiere.[37]

text: In July 2017, Neil Sandilands was announced to be cast as Clifford DeVoe, a metahuman genius who embarks on a seasonlong battle with the Flash in order to fix all that he deems wrong with humanity; while Kim Engelbrecht was announced as The Mechanic, Devoe's right hand and a highly intelligent engineer who designs devices for him; and Danny Trejo as Breacher, a bounty hunter from Earth-19 and the father of Gypsy.[28] Also in June, the series was looking to cast a role that "should put the visual effects department to the test",[85] with the role later revealed to be Ralph Dibny / Elongated Man, a metahuman with the ability to stretch his body to superhuman lengths and sizes.[86] Hartley Sawyer was cast in the recurring role that July as the fast-talking private investigator who after discovering his abilities will help Team Flash solve one of Central City's greatest mysteries.[34] The character was previously mentioned in the first season, as one of the fourteen people who seemingly died as a result of the particle accelerator explosion.[87] The next month, Katee Sackhoff was announced in the recurring role of Amunet Black / Blacksmith, who operates an underground black market of metahuman supervillains.[35]

text: Filming[edit]

text: Filming for the season began on July 4, 2017,[88] in Vancouver, British Columbia, and is set to conclude on April 21, 2018.[89] Kevin Smith will return to direct an episode in January 2018.[90]

text: Music[edit]

text: In August 2017, series composer Blake Neely and Nathaniel Blume began to compose the music for the fourth season.[91]

text: Arrowverse tie-ins[edit]

text: In May 2017, The CW president Mark Pedowitz officially announced plans for a four-show Arrowverse crossover event, crossing over episodes of the television series Supergirl, The Flash, Legends of Tomorrow, and Arrow.[92] The crossover, Crisis on Earth-X, began with Supergirl and a special airing of Arrow on November 27, 2017, and concluded on The Flash and Legends of Tomorrow on November 28.[93] In August 2017, Berlanti noted that it would be "a big life event for a few different people" that would bring them all together for the crossover, adding "There are many life events that happen."[94] Prior to that, Arrow actress Emily Bett Rickards appears as Felicity Smoak in the fifth episode of the season.[35]

text: Release[edit]

text: Broadcast[edit]

text: The season began airing on October 10, 2017, on The CW in the United States,[95] and on CTV in Canada.[96] Sky One acquired the rights to air the season in the UK & Ireland, airing it alongside the other Arrowverse shows. The season premiered October 17.[97][98]

text: Marketing[edit]

text: In July 2017, cast from the series appeared at San Diego Comic-Con International to promote the season, where exclusive footage was shown.[99] During the panel, a trailer for the season was shown, with James Whitbrook at io9 feeling that despite the "grim" tone, there was "some fun signs of the team coming together to protect the city without [Barry],... Sprinkle in a few wacky things, like, say a goddamn Samuroid ripped straight from the comics, and ladies and gents, you've got a good season of The Flash lined up."[100] Ben Pearson with /Film felt seeing Iris West deal with the absence of Barry was "a nice change of pace for that character", but anticipated that "Barry [would] be back two or three episodes in at the latest."[101] Collider.com's Allison Keene also noted Iris "getting an actual storyline" with Barry gone, and similarly presumed that he "[would] be back in the fold by the end of the first episode" alike to Flashpoint in the third season. She added, "There are some new foes, lots of action, plenty of tech — it's great!"[102]

text: Reception[edit]

text: Ratings[edit]

text:
No.
Title
Air date
Rating/share
(18–49)
Viewers
(millions)
DVR
(18–49)
DVR viewers
(millions)
Total
(18–49)
Total viewers
(millions)

1
"The Flash Reborn"
October 10, 2017
1.1/4
2.84[2]
0.7
1.92
1.8
4.77[103]

2
"Mixed Signals"
October 17, 2017
0.9/4
2.54[3]
0.8
1.82
1.7
4.36[104]

3
"Luck Be a Lady"
October 24, 2017
1.0/4
2.62[4]
0.8
1.84
1.8
4.46[105]

4
"Elongated Journey Into Night"
October 31, 2017
0.7/3
1.99[5]
0.7
1.79
1.4
3.79[106]

5
"Girls Night Out"
November 7, 2017
0.9/4
2.38[6]
0.8
1.84
1.7
4.22[107]

6
"When Harry Met Harry..."
November 14, 2017
1.0/4
2.46[7]
0.7
1.83
1.7
4.29[108]

7
"Therefore I Am"
November 21, 2017
0.8/3
2.20[8]
0.8
2.08
1.6
4.28[109]

8
"Crisis on Earth-X, Part 3"
November 28, 2017
1.0/4
2.82[9]
0.7
1.83
1.7
4.64[110]

9
"Don't Run"
December 5, 2017
0.8/3
2.22[10]
0.6
1.45
1.4
3.67[111]

10
"The Trial of The Flash"
January 16, 2018
0.8/3
2.51[11]
0.7
1.55
1.5
4.06[112]

11
"The Elongated Knight Rises"
January 23, 2018
0.7/3
2.12[12]
0.7
1.69
1.4
3.81[113]

12
"Honey, I Shrunk Team Flash"
January 30, 2018
0.9/3
2.60[13]
0.8
1.84
1.7
4.43[114]

13
"True Colors"
February 6, 2018
0.8/3
2.28[14]
0.9
2.00
1.7
4.28[115]

14
"Subject 9"
February 27, 2018
0.7/3
2.12[15]
0.8
1.86
1.5
3.98[116]

15
"Enter Flashtime"
March 6, 2018
0.7/3
2.04[16]
0.8
1.83
1.5
3.87[117]

16
"Run, Iris, Run"
March 13, 2018
0.7/3
2.09[17]
0.7
1.58
1.4
3.67[118]

17
"Null and Annoyed"
April 10, 2018
0.6/2
1.82[18]
TBD
TBD
TBD
TBD

18
"Lose Yourself"
April 17, 2018
0.7/3
1.88[19]
TBD
TBD
TBD
TBD

19
"Fury Rogue"
April 24, 2018
0.6/2
1.90[20]
TBD
TBD
TBD
TBD

text: Critical response[edit]

text: The review aggregator website Rotten Tomatoes reported a 100% approval rating with an average rating of 7.36/10 based on 14 reviews. The website's consensus reads, "After an unsteady turn in season three, The Flash returns to its roots with a fourth season packed with humor, spectacle, and a whole lot of heart."[119]

text: Reviewing the first two episodes of the season, Allison Keene writing for Collider.com, felt the premiere "wipes the slate clean, fixing a lot of the issues that plagued the end of the last season, and setting up a much more toned-down storyline. Most importantly, it's brought back some fun." She added that with a "streamlined team," the core characters now have time to interact and have meaningful plot lines. On the second episode, Keene described it as "truly a delight" with the show taking "the time to focus on character relationships, and not just romantic relationships" and each character "feeling like a refreshed version of themselves, with new narrative purpose". She also highlighted the setup of the Thinker "as an Alchemy-like villain who manipulates evil metas into the Flash's path as part of some kind of masterplan", saying "The Flash is a series that truly works best as a procedural, with the team finding creative ways to bring down Villains of the Week."[120]

text: Accolades[edit]

text:
Year
Award
Category
Nominee(s)
Result
Ref.

2018
Kids' Choice Awards
Favorite TV Actor
Grant Gustin
Nominated
[121]

Favorite TV Show
The Flash
Nominated

Saturn Awards
Best Guest-Starring Performance on Television
Hartley Sawyer
Pending
[122]

Best Superhero Television Series
The Flash
Pending

Best Supporting Actress on a Television Series
Candice Patton
Pending


document_title: List of Olympic Games host cities

question_text: when was the last summer olympics in the usa

text: List of Olympic Games host cities

text: Olympic Games host cities[edit]

text:
City
Country
Continent
Summer (Olympiad)
Winter
Year
Opening Ceremony
Closing Ceremony

Athens
 Greece
Europe
S005I
—
1896
000000002018-04-06-0000April 6
000000002018-04-15-0000April 15

Paris
 France
Europe
S005II
—
1900
000000002018-05-14-0000May 14
000000002018-10-28-0000October 28

St. Louis[a]
 United States
North America
S005III
—
1904
000000002018-07-01-0000July 1
000000002018-11-23-0000November 23

London[c]
 United Kingdom
Europe
S005IV
—
1908
000000002018-04-27-0000April 27
000000002018-10-31-0000October 31

Stockholm
 Sweden
Europe
S005V
—
1912
000000002018-05-05-0000May 5
000000002018-07-22-0000July 22

Berlin
 Germany
Europe
S006VI
—
1916
Cancelled due to WWI[4]

Antwerp[d]
 Belgium
Europe
S007VII
—
1920
000000002018-04-20-0000April 20
000000002018-09-12-0000September 12[5]

Chamonix
 France
Europe
—
W001I
1924
000000002018-01-25-0000January 25
000000002018-02-04-0000February 4[6]

Paris
 France
Europe
S008VIII
—
000000002018-05-04-0000May 4
000000002018-07-27-0000July 27[7]

St. Moritz
  Switzerland
Europe
—
W002II
1928
000000002018-02-11-0000February 11
000000002018-02-19-0000February 19[8]

Amsterdam
 Netherlands
Europe
S009IX
—
000000002018-05-17-0000May 17
000000002018-08-12-0000August 12[9]

Lake Placid
 United States
North America
—
W003III
1932
000000002018-02-04-0000February 4
000000002018-02-15-0000February 15[10]

Los Angeles
 United States
North America
S010X
—
000000002018-07-30-0000July 30
000000002018-08-14-0000August 14[11]

Garmisch-Partenkirchen
 Nazi Germany
Europe
—
W004IV
1936
000000002018-02-06-0000February 6
000000002018-02-16-0000February 16[12]

Berlin
 Nazi Germany
Europe
S011XI
—
000000002018-08-01-0000August 1
000000002018-08-16-0000August 16[13]

Sapporo
Garmisch-Partenkirchen[e]
 Empire of Japan
 Nazi Germany
Asia
Europe
—
W005aV
1940
Cancelled due to WWII[4]

Tokyo
Helsinki[f]
 Empire of Japan
 Finland
Asia
Europe
S012XII
—

Cortina d'Ampezzo
 Italy
Europe
—
W005bV
1944

London
 United Kingdom
Europe
S013XIII
—

St. Moritz
  Switzerland
Europe
—
W005cV
1948
000000002018-01-30-0000January 30
000000002018-02-08-0000February 8

London
 United Kingdom
Europe
S014XIV
—
000000002018-07-29-0000July 29
000000002018-08-14-0000August 14

Oslo
 Norway
Europe
—
W006VI
1952
000000002018-02-14-0000February 14
000000002018-02-25-0000February 25

Helsinki
 Finland
Europe
S015XV
—
000000002018-07-19-0000July 19
000000002018-08-03-0000August 3

Cortina d'Ampezzo
 Italy
Europe
—
W007VII
1956
000000002018-01-26-0000January 26
000000002018-02-05-0000February 5

Melbourne
Stockholm[g]
 Australia
 Sweden
Oceania
Europe
S016XVI
—
000000002018-11-22-0000November 22
000000002018-06-10-0000June 10
000000002018-12-08-0000December 8
000000002018-06-17-0000June 17

Squaw Valley
 United States
North America
—
W008VIII
1960
000000002018-02-18-0000February 18
000000002018-02-28-0000February 28

Rome
 Italy
Europe
S017XVII
—
000000002018-08-25-0000August 25
000000002018-09-11-0000September 11

Innsbruck
 Austria
Europe
—
W009IX
1964
000000002018-01-29-0000January 29
000000002018-02-09-0000February 9

Tokyo
 Japan
Asia
S018XVIII
—
000000002018-10-10-0000October 10
000000002018-10-24-0000October 24

Grenoble
 France
Europe
—
W010X
1968
000000002018-02-06-0000February 6
000000002018-02-18-0000February 18

Mexico City
 Mexico
North America
S019XIX
—
000000002018-10-12-0000October 12
000000002018-10-27-0000October 27

Sapporo
 Japan
Asia
—
W011XI
1972
000000002018-02-03-0000February 3
000000002018-02-13-0000February 13

Munich
 West Germany
Europe
S020XX
—
000000002018-08-26-0000August 26
000000002018-09-11-0000September 11

Innsbruck
 Austria
Europe
—
W012XII
1976
000000002018-02-04-0000February 4
000000002018-02-15-0000February 15

Montreal
 Canada
North America
S021XXI
—
000000002018-07-17-0000July 17
000000002018-08-01-0000August 1

Lake Placid
 United States
North America
—
W013XIII
1980
000000002018-02-12-0000February 12
000000002018-02-24-0000February 24

Moscow
 Soviet Union
Europe[h]
S022XXII
—
000000002018-07-19-0000July 19
000000002018-08-03-0000August 3

Sarajevo
 Yugoslavia
Europe
—
W014XIV
1984
000000002018-02-07-0000February 7
000000002018-02-19-0000February 19

Los Angeles
 United States
North America
S023XXIII
—
000000002018-07-28-0000July 28
000000002018-08-12-0000August 12

Calgary
 Canada
North America
—
W015XV
1988
000000002018-02-13-0000February 13
000000002018-02-28-0000February 28

Seoul
 South Korea
Asia
S024XXIV
—
000000002018-09-17-0000September 17
000000002018-10-02-0000October 2

Albertville
 France
Europe
—
W016XVI
1992
000000002018-02-08-0000February 8
000000002018-02-23-0000February 23

Barcelona
 Spain
Europe
S025XXV
—
000000002018-07-25-0000July 25
000000002018-08-09-0000August 9

Lillehammer
 Norway
Europe
—
W017XVII
1994
000000002018-02-12-0000February 12
000000002018-02-27-0000February 27

Atlanta
 United States
North America
S026XXVI
—
1996
000000002018-07-19-0000July 19
000000002018-08-04-0000August 4

Nagano
 Japan
Asia
—
W018XVIII
1998
000000002018-02-07-0000February 7
000000002018-02-22-0000February 22

Sydney
 Australia
Oceania
S027XXVII
—
2000
000000002018-09-15-0000September 15
000000002018-10-01-0000October 1

Salt Lake City
 United States
North America
—
W019XIX
2002
000000002018-02-08-0000February 8
000000002018-02-24-0000February 24

Athens
 Greece
Europe
S028XXVIII
—
2004
000000002018-08-13-0000August 13
000000002018-08-29-0000August 29

Torino
 Italy
Europe
—
W020XX
2006
000000002018-02-10-0000February 10
000000002018-02-26-0000February 26

Beijing[i]
 China
Asia
S029XXIX
—
2008
000000002018-08-08-0000August 8
000000002018-08-24-0000August 24

Vancouver
 Canada
North America
—
W021XXI
2010
000000002018-02-12-0000February 12
000000002018-02-28-0000February 28

London
 United Kingdom
Europe
S030XXX
—
2012
000000002018-07-27-0000July 27
000000002018-08-12-0000August 12

Sochi
 Russia
Europe[h]
—
W022XXII
2014
000000002018-02-07-0000February 7
000000002018-02-23-0000February 23

Rio de Janeiro
 Brazil
South America
S031XXXI
—
2016
000000002018-08-05-0000August 5
000000002018-08-21-0000August 21

Pyeongchang
 South Korea
Asia
—
W023XXIII
2018
000000002018-02-09-0000February 9
000000002018-02-25-0000February 25

Tokyo
 Japan
Asia
S032XXXII
—
2020
000000002018-07-24-0000July 24
000000002018-08-09-0000August 9

Beijing
 China
Asia
—
W024XXIV
2022
000000002018-02-04-0000February 4
000000002018-02-20-0000February 20

Paris
 France
Europe
S033XXXIII
—
2024
000000002018-07-26-0000July 26
000000002018-08-11-0000August 11

TBD
TBD

—
W025XXV
2026
(TBD)

Los Angeles
 United States
North America
S034XXXIV
—
2028
000000002018-07-21-0000July 21
000000002018-08-06-0000August 6

TBD
TBD

—
W026XXVI
2030
(TBD)

text: Host cities for multiple Summer and Winter Olympic Games[edit]

text:
List of cities that hosted multiple editions of the Olympic Games

City
Country
Continent
Summer Olympics
Winter Olympics
Total

London
 United Kingdom
Europe
3 (1908, 1948, 2012)
0
3

Paris
 France
Europe
3 (1900, 1924, 2024)
0

Los Angeles
 United States
North America
3 (1932, 1984, 2028)
0

Athens
 Greece
Europe
2 (1896, 2004)
0
2

Tokyo
 Japan
Asia
2 (1964, 2020)
0

Beijing
 China
Asia
1 (2008)
1 (2022)

St. Moritz
  Switzerland
Europe
0
2 (1928, 1948)

Innsbruck
 Austria
Europe
0
2 (1964, 1976)

Lake Placid
 United States
North America
0
2 (1932, 1980)

text: The 1906 Intercalated Games are not officially recognized by the IOC as an official Olympic Games.

text: Number of Olympic Games by country[edit]

text:
List of countries ranked by the number of times they hosted the Olympic Games

Rank
Country
Continent
Summer Olympics
Winter Olympics
Total

1
 United States
North America
5 (1904, 1932, 1984, 1996, 2028)
4 (1932, 1960, 1980, 2002)
9

2
 France
Europe
3 (1900, 1924, 2024)
3 (1924, 1968, 1992)
6

3
 Japan
Asia
2 (1940, 1964, 2020)
2 (1940, 1972, 1998)
4

4
 United Kingdom
Europe
3 (1908, 1944, 1948, 2012)
0
3

 Canada
North America
1 (1976)
2 (1988, 2010)

 Italy
Europe
1 (1960)
2 (1944, 1956, 2006)

 German Empire/ Nazi Germany/ West Germany/ Germany
Europe
2 (1916, 1936, 1972)
1 (1936, 1940)

8
 China
Asia
1 (2008)
1 (2022)
2

 South Korea
Asia
1 (1988)
1 (2018)

 Soviet Union/ Russia
Europe
1 (1980)
1 (2014)

 Greece
Europe
2 (1896, 2004)
0

 Australia
Oceania
2 (1956, 2000)
0

 Norway
Europe
0
2 (1952, 1994)

 Austria
Europe
0
2 (1964, 1976)

  Switzerland
Europe
0
2 (1928, 1940, 1948)

 Sweden
Europe
2 (1912, 1956 (equestrian events only))
0

17
 Brazil
South America
1 (2016)
0
1

 Spain
Europe
1 (1992)
0

 SFR Yugoslavia/ Bosnia and Herzegovina
Europe
0
1 (1984)

 Mexico
North America
1 (1968)
0

 Finland
Europe
1 (1940, 1952)
0

 Netherlands
Europe
1 (1928)
0

 Belgium
Europe
1 (1920)
0

text: Number of Olympic Games by continent[edit]

text:
Rank
Continent
Summer Olympics
Winter Olympics
Total

1
Europe
17 (1896, 1900, 1908, 1912, 1920, 1924, 1928, 1936, 1940, 1944, 1948, 1952, 1960, 1972, 1980, 1992, 2004, 2012, 2024)
14 (1924, 1928, 1936, 1940, 1944, 1948, 1952, 1956, 1964, 1968, 1976, 1984, 1992, 1994, 2006, 2014)
31

2
North America
7 (1904, 1932, 1968, 1976, 1984, 1996, 2028)
6 (1932, 1960, 1980, 1988, 2002, 2010)
13

3
Asia
4 (1940, 1964, 1988, 2008, 2020)
4 (1940, 1972, 1998, 2018, 2022)
8

4
Oceania
2 (1956, 2000)
0
2

5
South America
1 (2016)
0
1

6
Africa
0
0
0

text: Unsuccessful cities[edit]

text: This section does not cite any sources. Please help improve this section by adding citations to reliable sources. Unsourced material may be challenged and removed. (February 2018) (Learn how and when to remove this template message)

text:
Country
City
Bids

 United States
Detroit
7

 Hungary
Budapest
6

 Turkey
Istanbul
5

 Spain
Madrid
4

 Argentina
Buenos Aires
4

  Switzerland
Lausanne
4

 United States
Philadelphia
5

 United States
Chicago
4

 United States
Minneapolis
3

 Cuba
Havana
3

 Belgium
Brussels
3

 Azerbaijan
Baku
2

 Qatar
Doha
2

 Spain
Seville
2

 Yugoslavia
Belgrade
2

 Puerto Rico
San Juan
1

 Australia
Brisbane
1

 Slovakia
Poprad
1

 United States
Boston
1