document_title: 2017 Las Vegas shooting

question_text: who was playing during the las vegas shooting

text: 2017 Las Vegas shooting

text: Background[edit]

text: Location[edit]

text: The Las Vegas Strip is a stretch of Las Vegas Boulevard immediately south of the city of Las Vegas in Clark County, Nevada. The Strip is known for its concentration of casinos and resort hotels, including the 43-story Mandalay Bay southwest of its intersection with Mandalay Bay Road, in the unincorporated town of Paradise.[2]

text: Las Vegas Village, a 15-acre (6.1-hectare) lot used for outdoor performances, is located diagonally across the intersection to the northeast.[2][3] From 2014 onward, the venue hosted the annual Route 91 Harvest country music festival. The 2017 festival ran from September 29 to October 1, with over 22,000 attendees on the final day.[3][4][a]

text: Perpetrator[edit]

text: Stephen Paddock was a 64-year-old former auditor and real estate businessman who had been living 80 miles (130 km) northeast of Las Vegas in a retirement community in Mesquite, Nevada.[5] Paddock was twice divorced, had a long-term girlfriend, and had no known children.[6] He was a son of Benjamin Paddock, a bank robber who was on the FBI's most-wanted list between 1969 and 1977.[6] Paddock's only recorded interactions with law enforcement were traffic citations.[7]

text: Paddock was a high-stakes gambler who placed bets at a high enough level to earn valuable comps—free benefits such as rooms and meals.[8] He was a familiar figure to casino hosts in Las Vegas, but was not well known among other high-stakes gamblers because he mostly played video poker.[8] He reportedly kept to himself and was a heavy drinker.[9] Paddock had lost a significant amount of his wealth over the previous two years,[10] but had paid off all gambling debts before the shooting.[11]

text: Paddock may have considered attacking other events. He had researched large-scale venues in cities such as Boston since at least May 2017,[11] and had reserved a room overlooking the August 2017 Lollapalooza festival in Chicago, but did not use it.[12] According to his girlfriend, she and Paddock were at the Mandalay Bay during an earlier stay a month before the attack when he repeatedly cased out Las Vegas Village from different windows in their room.[13] From September 17, Paddock stayed at The Ogden in Downtown Las Vegas, which overlooked the open-air Life Is Beautiful festival that ran from September 22 to September 24.[13][4] His internet search terms from mid-September included "swat weapons", "ballistics chart 308", "SWAT Las Vegas", and "do police use explosives".[13]

text: Shooting[edit]

text: Preparation[edit]

text: Paddock arrived at the Mandalay Bay on September 25, 2017. He was booked into Room 32-135, a complimentary room on the 32nd floor.[4][8] Four days later, he also checked into the directly-connected Room 32-134. Both suites overlook the site of the concert at Las Vegas Village.[4][14][b] Between September 25 and October 1—the day of the shooting—he stockpiled an arsenal of weapons, associated equipment and ammunition that included fourteen AR-15 rifles (twelve of which had bump stocks and 100-round magazines), eight AR-10 rifles, a bolt-action rifle, and a revolver. Often with the help of hotel bellhops, he brought five suitcases to his room on September 25, seven on the 26th, two on the 28th, six on the 30th, and two on October 1.[15][13][4] Cell phone records also show that he also made multiple visits to his home in Mesquite. On September 30, he placed "Do not disturb" signs on the doors of both rooms.[15] Paddock spent much of his time at the Mandalay Bay before the shooting gambling, often at night. He interacted with Mandalay Bay employees more than ten times during his stay, including twice on the day of the shooting; an MGM Resorts International spokesperson said they were all "normal in nature".[16]

text: Attack[edit]

text: The mass shooting occurred between 10:05 and 10:15 p.m. PDT on October 1, 2017, which was the third and final night of the festival. When the shooting began, country music singer Jason Aldean was giving the closing performance.[17]

text: Shortly before 10:00 p.m., hotel security guard Jesus Campos was sent to the 32nd floor to investigate an open-door alert. He attempted to open a door that provided immediate access to the floor, but found that it would not open. After Campos entered the floor, he discovered an L-shaped bracket screwed into the door and door frame, which was responsible for barring the door from opening. After reporting the discovery to his dispatch center, he heard the sound of rapid drilling coming from Room 32-135 and went to investigate the matter. At approximately 10:05, he was hit in the right thigh by one of about 35 bullets that Paddock fired through the door of his suite. After Campos was hit, he took cover in the alcove between Rooms 32-122 and 32-124 and immediately informed the hotel by radio and cellphone that he had been shot, though he believed he had been shot with a BB or pellet gun. At the same time, maintenance worker Stephen Schuck was on the same floor to fix the door that Campos had reported as being barricaded. Campos, who was already injured, encountered Schuck and told him to take cover. Schuck contacted hotel dispatchers over his radio, informed them of the ongoing shooting, and told them to call the police.[4][18][19][20][21] Neither Las Vegas Metropolitan Police Department nor MGM Resorts International, the Mandalay Bay's owner, have confirmed when information about the initial shooting was relayed to the police.[22][23][24][25]

text:
1

2

3

1

Mandalay Bay hotel

2

Main stage of Route 91 Harvest festival

3

Jet fuel tanks at McCarran International Airport

text: After Paddock used a hammer to break two of the windows in both of his suites,[4] he began shooting through them at 10:05 p.m.[26] He ultimately fired more than 1,100 rifle rounds[27] approximately 490 yards (450 m) into the festival audience.[28][29][30][c] He initially started out with a few single gunshots before firing in prolonged bursts.[4] Many people in the crowd initially mistook the gunfire for fireworks.[31] During the shooting, a security fence hindered concertgoers from fleeing the 15-acre concrete lot.[32] The gunfire continued, with some momentary pauses, over the span of ten minutes and ended by 10:15 p.m.[33][34]

text: In addition to shooting at the concertgoers, Paddock fired eight bullets at a large jet fuel tank at McCarran International Airport 2,000 feet (600 m) away.[4] Two of those bullets struck the exterior of the tank, with one bullet penetrating the tank. The fuel did not explode because jet fuel is mostly kerosene, which is unlikely to ignite when struck by a bullet.[35]

text: During the shooting, police officers were initially confused whether the shots were coming from the Mandalay Bay, the nearby Luxor hotel, or the festival grounds.[32] There were also multiple false reports of additional shooters at other hotels on the Strip.[36] Officers eventually spotted multiple flashes of gunfire in the middle of the northern side of Mandalay Bay and responded to the hotel. At 10:12 p.m., two officers on the 31st floor reported the sounds of gunfire on the floor above them.[32] When officers arrived on the 32nd floor at 10:17 p.m. and encountered Campos a minute later, he directed them to Paddock's room and helped others evacuate. Campos was then directed to seek medical attention for himself.[19][21]

text: Between 10:26 and 10:30 p.m., eight additional officers arrived at the 32nd floor; some of those officers manually breached through the door Paddock had screwed shut with the bracket. The gunfire had ceased, and the police moved systematically down the hallway, searching and clearing each room, using a master key that was provided by Campos. At 10:55 p.m., the officers finished evacuating guests. At 11:20 p.m., police breached Room 32-135 with explosives.[4][32][34][37] Paddock was found dead on the floor from a self-inflicted gunshot wound to the head.[38][39] Police then breached Room 32-134; while entering the hotel suite, an officer accidentally fired a three-round burst from his weapon, but the bullets did not hit anyone.[4][40] At 11:27 p.m., officers announced over the police radio that a suspect was down.[34][41]

text: Immediate response[edit]

text: Much of Las Vegas Boulevard was closed while police SWAT teams combed the venue and neighboring businesses. McCarran International Airport, adjacent to the shooting site, was shut down for several hours.[42] Approximately 300 people entered the airport property as they fled to safety from the shooting.[31] This prompted officials to shut down all four runways. More than 25 flights were rerouted to ensure that no aircraft would be hit by gunfire,[36] while other flights were canceled before airfield operations resumed at 12:40 a.m. on October 2.[43] At approximately 2:45 p.m. PDT on October 2, a state of emergency was declared in Clark County.[44][45]

text: Early on October 2, Sheriff Lombardo identified the suspect as Stephen Paddock.[46]

text: Casualties[edit]

text: Fifty-eight people were shot to death at the music festival; Paddock's suicide was the only death at the Mandalay Bay Hotel.[47][48][49] The fatalities included 36 women and 22 men.[47] The oldest was 67, the youngest 20.[50] Six were from Nevada, 35 from California, 13 from other states, and four from Canada.[51] The Clark County Coroner's Office determined that all 58 victims died as a result of gunshot wounds.[52] Thirty one of the victims were pronounced dead at the scene, while the rest were pronounced dead at hospitals.[11]

text: An additional 851 people were injured, 422 of them with gunshot wounds.[24][53] In the aftermath, many victims were transported to area hospitals, which included University Medical Center of Southern Nevada, Sunrise Hospital & Medical Center, and at least one of the six hospitals of Valley Health System.[54][55][56] Sunrise Hospital treated the largest portion of the wounded: 199 patients,[57] 150 of whom arrived within a timespan of about 40 minutes.[58] For reasons that are unclear, most patients were transported to Sunrise, a Level II trauma center. University Medical Center, a nearby Level I trauma center, treated 104 patients.[59] Six victims sought medical treatment in Southern California; UC Irvine Medical Center treated four and Loma Linda University Medical Center treated two.[60]

text: The incident is the deadliest mass shooting committed by an individual in the United States, exceeding the death toll of the 2016 Orlando nightclub shooting, where 49 people were shot and killed.[47][61][62]

text: Aftermath[edit]

text: On the morning after the shooting, lines to donate blood in Las Vegas stretched for blocks. Wait times were as much as six hours or more.[63] Millions of dollars have also been raised to help victims and their families.[64]

text: Nevada Governor Brian Sandoval called the shooting "a tragic and heinous act of violence that has shaken the Nevada family".[65] Jason Aldean, who was singing when the shooting started, posted his condolences on Instagram and noted all of those working with him at the show had survived the attack.[66]

text: At a press conference, President Donald Trump described Paddock as "a very very sick individual", and "a demented man, [with] a lot of problems". He added, "the police department has done such an incredible job, and we'll be talking about gun laws as time goes by".[67][68] A White House official talking points memo, distributed to Trump allies, opposed tightening gun control since "new laws won't stop a mad man", but "will curtail the freedoms of law abiding citizens".[69] On October 2, Trump issued a proclamation to honor the victims and their families.[70][71] On October 4, Trump visited the shooting victims and first responders.[72]

text: A unity prayer walk and ceremony was held in Las Vegas on October 7 in honor of the dead. Speakers at the ceremony included Vice President Mike Pence and Las Vegas Mayor Carolyn Goodman.[73] On the evening of October 15, thousands participated in a commemorative 3 mile walk between Circus Circus and Mandalay Bay.[74]

text: The annual Rock 'n' Roll Las Vegas Marathon took place on November 12 and was the largest event to be held in the city since the shooting. The event received a massive amount of security, which included 350 officers, counter-sniper surveillance posts, and a number of barriers composed of dump trucks, buses, and other large vehicles.[75]

text: The expansion Vegas Golden Knights of the NHL held a tribute to the victims and honoured response personnel before their inaugural home game on October 10.[76] Later during the season, the number 58 became the first number in team history to be retired, chosen for the 58 deaths during the shooting.[77]

text: The future of the Las Vegas Village site remains undetermined.[78]

text: Gun control discussion[edit]

text: The shooting prompted support in the U.S. Congress for assault weapons legislation that would ban bump fire stocks. The National Rifle Association (NRA) came out in favor of administrative bump fire stock regulations.[47] Many Congressional Democrats and some Republicans expressed their support of a prohibition of bump fire stocks.[79] Senator Dianne Feinstein introduced a Senate bill that gained 39 Democratic co-sponsors. Two bipartisan bills have been introduced in the House of Representatives. As of November, no Congressional action has been taken. House leaders said the issue of bump fire stock regulation should be decided by the Bureau of Alcohol, Tobacco, and Firearms, which originally approved gun-stocks.[80] On November 6, Massachusetts became the first state to ban the sale, possession, or use of the devices.[81]

text: Nine days after the shooting, eighteen Democratic U.S. Senators introduced a bill, the Keep Americans Safe Act, which, if signed into law, would ban gun magazines that hold more than ten rounds of ammunition.[82]

text: Stock prices of firearms manufacturers rose the day after the shooting, as has happened after similar incidents. Investors expect gun sales will increase over concerns that such an event could lead to more stringent gun-control legislation and a rush of customers wishing to defend themselves against future attacks.[83][84]

text: Investigation[edit]

text: According to authorities with the Clark County Commissioner, the name "1 October" was declared the official title for investigations into the mass shooting.[85]

text: Early reports[edit]

text: Investigators found hidden surveillance cameras that were placed inside and outside the hotel room, presumably so Paddock could monitor the arrival of others.[86] The cameras were not in record mode.[87] Police said a handwritten note found in the room indicated Paddock had been calculating the distance, wind, and trajectory from his 32nd floor hotel suite to the concertgoers he was targeting on the festival lot.[88][89]

text: At a press conference on October 4, Clark County Sheriff Joe Lombardo stated there was evidence—which he declined to discuss—that Paddock intended to escape the scene, and that he may have had assistance from an accomplice.[90] Investigators searched Paddock's room and found a "bulletproof vest" and breathing apparatus, which were survival gear that Paddock never used.[91]

text: There have been several changes in the official account and timeline of Paddock's shooting of hotel security guard Campos. Police officials described these adjustments as "minute changes" that are common in complex investigations.[19]

text: In their first statement about the incident, police officials inaccurately reported that Campos arrived on the scene after Paddock began firing into the crowd. In a second statement, police officials reported, again inaccurately, that Campos was shot six minutes before Paddock began firing into the crowd. That report had been based on a 9:59 p.m. notation in a hotel security log, which in a third statement was determined to have been the time when Campos encountered the barricaded door.[18][20]

text: Sheriff Lombardo dismissed allegations that the changing timeline was the result of some kind of conspiracy between the police department, the FBI, and MGM Resorts International saying, "Nobody is attempting to hide anything in reference to this investigation. The dynamics and the size of this investigation requires us to go through voluminous amounts of information in order to draw an accurate picture."[18]

text: Preliminary investigation[edit]

text: Although the investigation remains ongoing, the Las Vegas Metropolitan Police Department released a preliminary report on the event on January 18, 2018.[4]

text: Police speculate that Paddock acted alone and have not determined his motive. No links have been identified to any hate groups, terrorist groups or ideologies, and he did not record a reason for his actions.[92]

text: On February 2, 2018, Douglas Haig, an Arizonan ammunition dealer, was charged in a Nevada federal court with "conspiracy to manufacture and sell armor-piercing ammunition without a license" after his fingerprints were discovered on unfired armor-piercing ammunition inside Paddock's suite.[93]

text: Weaponry[edit]

text: Twenty-four firearms, a large quantity of ammunition, and numerous high-capacity magazines capable of holding up to 100 rounds apiece were found in the suite.[1][94][95] Fourteen of the firearms were .223-caliber AR-15-type semi-automatic rifles: three manufactured by Colt, two by Daniel Defense, two by FN Herstal, two by LWRC International, two by POF-USA, one with a .223 Wylde chamber by Christensen Arms, one made-to-order by LMT, and one by Noveske. The others were eight .308-caliber AR-10-type rifles, one .308-caliber Ruger American bolt-action rifle, and one .38-caliber Smith & Wesson Model 342 revolver.[1][96][97][98] The AR-15 rifles were fitted with vertical forward grips and bump fire stocks,[1][96] the latter of which allowed for recoil to actuate their triggers at a rate of 90 rounds in 10 seconds.[99] The AR-10 rifles were equipped with various telescopic sights and mounted on bipods.[1][100][101] The Bureau of Alcohol, Tobacco, Firearms and Explosives determined that the firearms found in his hotel room, along with more guns found in his homes, had been legally purchased in Nevada, California, Texas, and Utah.[102] In the month preceding the shooting, he had attempted to purchase tracer ammunition, but the gun dealer he approached did not have the item in stock.[103] He bought tracer ammunition from a private seller at a Phoenix, Arizona gun show.[104]

text: During subsequent investigations, ammonium nitrate (often used in improvised explosive devices) was found in the trunk of his Hyundai Tucson SUV, along with 1,600 rounds of ammunition and 50 pounds (23 kg) of Tannerite, a binary explosive used to make explosive targets for gun ranges.[105][106] Undersheriff Kevin McMahill said that while Paddock had "nefarious intent" with the material, he did not appear to have assembled an explosive device.[103][107]

text: Conspiracy theories[edit]

text: In the hours and days after the shooting, false information and fake news about the shooter's identity and motive went viral on social media:

text:
A 4chan /pol/ thread, which misidentified the shooter and described him as a registered Democrat, briefly featured in the "Top Stories" section of a Google search for the man's name. The misinformation was circulated by a number of websites including The Gateway Pundit.[108][109]
The fake news website YourNewsWire spread false information about a second gunman who was shooting from the fourth floor of the hotel.[110]
Two of Facebook's top trending pages were items from Sputnik, a Russian government news agency. These included one story that falsely claimed the FBI had linked the shooter to a terrorist group. The stories were later removed from Sputnik with an apology.[111][112]
Stories linking the shooter to Antifa have also been discredited.[113]
The terrorist group Islamic State of Iraq and the Levant (ISIS) claimed that Paddock was their "soldier" and that he had answered Abu Bakr al-Baghdadi's call to attack coalition countries.[114] ISIS provided no evidence for its claim, and had previously released multiple false claims of responsibility for incidents with which they had no connection.[115][116] On October 9, 2017, the FBI declared that Paddock's attack was not linked to international terrorism.[117]

tag: ul

text: Google and Facebook were criticized for displaying such false news stories in some of their search results.[111][118][119] The two technology companies were said to have failed in their responsibility of keeping false stories from reaching the public.[120] Facebook later said its algorithms were designed to detect and remove false stories, but failed to work adequately in this instance.[118]

text: In the aftermath of the shooting, some media outlets reported that YouTube search results for information about the shooting returned links to conspiracy videos. YouTube stated that it had tweaked its search algorithm to promote news sources which it considered more authoritative.[121][122] Some experts have stated that the removal of this content ironically fuels conspiracy theories by making a cover-up seem evident.[123]

text: Survivors of the shooting have been accused of being paid actors, with some having received death threats on social media.[124]

text: Conspiracy theorist Alex Jones stated that "Vegas is as phony as a three dollar bill or as Obama's birth certificate."[125] Conspiracy theorists claim that there were multiple shooters and that details of the massacre are being covered up for the sake of promoting gun control laws.[123]


document_title: Mosquito

question_text: how many different species of mosquitoes are there

question_tokens: how many different species of mosquitoes are there

root

text: Mosquito

text: Taxonomy and evolution

text: The oldest known mosquito with an anatomy similar to modern species was found in 79-million-year-old Canadian amber from the Cretaceous.[7] An older sister species with more primitive features was found in Burmese amber that is 90 to 100 million years old.[8] Two mosquito fossils have been found that show very little morphological change in modern mosquitoes against their counterpart from 46 million years ago.[9]  These fossils are also the oldest ever found to have blood preserved within their abdomens.[10][11] Despite no fossils being found earlier than the Cretaceous, recent studies suggest that the earliest divergence of mosquitoes between the lineages leading to Anophelinae and Culicinae occurred 226 million years ago.[12]

tag: p

text: The Old and New World Anopheles species are believed to have subsequently diverged about 95 million years ago.[13]

text:
The mosquito Anopheles gambiae is currently undergoing speciation into the M(opti) and S(avanah) molecular forms. Consequently, some pesticides that work on the M form no longer work on the S form.[14]
Over 3,500 species of the Culicidae have already been described.[15] They are generally divided into two subfamilies which in turn comprise some 43 genera. These figures are subject to continual change, as more species are discovered, and as DNA studies compel rearrangement of the taxonomy of the family. The two main subfamilies are the Anophelinae and Culicinae, with their genera as shown in the subsection below.[16] The distinction is of great practical importance because the two subfamilies tend to differ in their significance as vectors of different classes of diseases. Roughly speaking, arboviral diseases such as yellow fever and dengue fever tend to be transmitted by Culicine species, not necessarily in the genus Culex. Some transmit various species of avian malaria, but it is not clear that they ever transmit any form of human malaria. Some species do however transmit various forms of filariasis, much as many Simuliidae do.

text: Anopheline mosquitoes, again not necessarily in the genus Anopheles, sometimes bear pathogenic arboviruses, but it is not yet clear that they ever transmit them as effective vectors. However, all the most important vectors of human malaria are Anopheline.[clarification needed]

text: Subfamilies

text:
Anophelinae
Culicinae

text: Genera

text:
Aedeomyia
Aedes
Anopheles
Armigeres
Ayurakitia
Borachinda
Coquillettidia
Culex
Culiseta
Deinocerites
Eretmapodites
Ficalbia
Galindomyia
Haemagogus
Heizmannia
Hodgesia
Isostomyia
Johnbelkinia
Kimia
Limatus
Lutzia
Malaya
Mansonia
Maorigoeldia
Mimomyia
Onirion
Opifex
Orthopodomyia
Psorophora
Runchomyia
Sabethes
Shannoniana
Topomyia
Toxorhynchites
Trichoprosopon
Tripteroides
Udaya
Uranotaenia
Verrallina
Wyeomyia

text: Species

text: Mosquitoes are members of a family of nematocerid flies: the Culicidae (from the Latin culex, genitive culicis, meaning "midge" or "gnat").[17] Superficially, mosquitoes resemble crane flies (family Tipulidae) and chironomid flies (family Chironomidae). In particular, the females of many species of mosquitoes are blood-eating pests and dangerous vectors of diseases, whereas members of the similar-looking Chironomidae and Tipulidae are not. Many species of mosquitoes are not blood eaters and of those that are, many create a "high to low pressure" in the blood to obtain it and do not transmit disease. Also, in the bloodsucking species, only the females suck blood.[18] Furthermore, even among mosquitoes that do carry important diseases, neither all species of mosquitoes, nor all strains of a given species transmit the same kinds of diseases, nor do they all transmit the diseases under the same circumstances; their habits differ. For example, some species attack people in houses, and others prefer to attack people walking in forests. Accordingly, in managing public health, knowing which species or even which strain of mosquito one is dealing with is important.

text: Over 3,500 species of mosquitoes have already been described from various parts of the world.[19][20] Some mosquitoes that bite humans routinely act as vectors for a number of infectious diseases affecting millions of people per year.[21][22] Others that do not routinely bite humans, but are the vectors for animal diseases, may become disastrous agents for zoonosis of new diseases when their habitats are disturbed, for instance by sudden deforestation.[23][24]

text: Lifecycle

text: Like all flies, mosquitoes go through four stages in their lifecycles: egg, larva, pupa, and adult or imago. In most species, adult females lay their eggs in stagnant water; some lay eggs near the water's edge; others attach their eggs to aquatic plants. Each species selects the situation of the water into which it lays its eggs and does so according to its own ecological adaptations. Some are generalists and are not very fussy. Some breed in lakes, some in temporary puddles. Some breed in marshes, some in salt-marshes. Among those that breed in salt water, some are equally at home in fresh and salt water up to about one-third the concentration of seawater, whereas others must acclimatize themselves to the salinity.[25] Such differences are important because certain ecological preferences keep mosquitoes away from most humans, whereas other preferences bring them right into houses at night.

text: Some species of mosquitoes prefer to breed in phytotelmata (natural reservoirs on plants), such as rainwater accumulated in holes in tree trunks, or in the leaf-axils of bromeliads. Some specialize in the liquid in pitchers of particular species of pitcher plants, their larvae feeding on decaying insects that had drowned there or on the associated bacteria; the genus Wyeomyia provides such examples — the harmless Wyeomyia smithii breeds only in the pitchers of Sarracenia purpurea.[26]

text: However, some of the species of mosquitoes that are adapted to breeding in phytotelmata are dangerous disease vectors. In nature, they might occupy anything from a hollow tree trunk to a cupped leaf. Such species typically take readily to breeding in artificial water containers. Such casual puddles are important breeding places for some of the most serious disease vectors, such as species of Aedes that transmit dengue and yellow fever. Some with such breeding habits are disproportionately important vectors because they are well-placed to pick up pathogens from humans and pass them on. In contrast, no matter how voracious, mosquitoes that breed and feed mainly in remote wetlands and salt marshes may well remain uninfected, and if they do happen to become infected with a relevant pathogen, might seldom encounter humans to infect, in turn.

text: The first three stages—egg, larva, and pupa—are largely aquatic. These stages typically last 5 to 14 days, depending on the species and the ambient temperature, but there are important exceptions. Mosquitoes living in regions where some seasons are freezing or waterless spend part of the year in diapause; they delay their development, typically for months, and carry on with life only when there is enough water or warmth for their needs. For instance, Wyeomyia larvae typically get frozen into solid lumps of ice during winter and only complete their development in spring. The eggs of some species of Aedes remain unharmed in diapause if they dry out, and hatch later when they are covered by water.

text: Eggs hatch to become larvae, which grow until they are able to change into pupae. The adult mosquito emerges from the mature pupa as it floats at the water surface. Bloodsucking mosquitoes, depending on species, sex, and weather conditions, have potential adult lifespans ranging from as short as a week to as long as several months.

text: Some species can overwinter as adults in diapause.[27][28]

text: Eggs and oviposition

text: Mosquito habits of oviposition, the ways in which they lay their eggs, vary considerably between species, and the morphologies of the eggs vary accordingly. The simplest procedure is that followed by many species of Anopheles; like many other gracile species of aquatic insects, females just fly over the water, bobbing up and down to the water surface and dropping eggs more or less singly. The bobbing behavior occurs among some other aquatic insects as well, for example mayflies and dragonflies; it is sometimes called "dapping". The eggs of Anopheles species are roughly cigar-shaped and have floats down their sides. Females of many common species can lay 100–200 eggs during the course of the adult phase of their lifecycles. Even with high egg and intergenerational mortality, over a period of several weeks, a single successful breeding pair can create a population of thousands.

text: Some other species, for example members of the genus Mansonia, lay their eggs in arrays, attached usually to the under-surfaces of waterlily pads. Their close relatives, the genus Coquillettidia, lay their eggs similarly, but not attached to plants. Instead, the eggs form layers called "rafts" that float on the water. This is a common mode of oviposition, and most species of Culex are known for the habit, which also occurs in some other genera, such as Culiseta and Uranotaenia. Anopheles eggs may on occasion cluster together on the water, too, but the clusters do not generally look much like compactly glued rafts of eggs.

text: In species that lay their eggs in rafts, rafts do not form adventitiously; the female Culex settles carefully on still water with its hind legs crossed, and as it lays the eggs one by one, it twitches to arrange them into a head-down array that sticks together to form the raft.[29]

text: Aedes females generally drop their eggs singly, much as Anopheles do, but not as a rule into water. Instead, they lay their eggs on damp mud or other surfaces near the water's edge. Such an oviposition site commonly is the wall of a cavity such as a hollow stump or a container such as a bucket or a discarded vehicle tire. The eggs generally do not hatch until they are flooded, and they may have to withstand considerable desiccation before that happens. They are not resistant to desiccation straight after oviposition, but must develop to a suitable degree first. Once they have achieved that, however, they can enter diapause for several months if they dry out. Clutches of eggs of the majority of mosquito species hatch as soon as possible, and all the eggs in the clutch hatch at much the same time. In contrast, a batch of Aedes eggs in diapause tends to hatch irregularly over an extended period of time. This makes it much more difficult to control such species than those mosquitoes whose larvae can be killed all together as they hatch. Some Anopheles species do also behave in such a manner, though not to the same degree of sophistication.[30]

text: Larva

text: The mosquito larva has a well-developed head with mouth brushes used for feeding, a large thorax with no legs, and a segmented abdomen.

text: Larvae breathe through spiracles located on their eighth abdominal segments, or through a siphon, so must come to the surface frequently. The larvae spend most of their time feeding on algae, bacteria, and other microbes in the surface microlayer.

text: They dive below the surface only when disturbed. Larvae swim either through propulsion with their mouth brushes, or by jerky movements of their entire bodies, giving them the common name of "wigglers" or "wrigglers".

text: Larvae develop through four stages, or instars, after which they metamorphose into pupae. At the end of each instar, the larvae molt, shedding their skins to allow for further growth.

text:
Mosquito larvae and pupa resting at water surface

Anopheles larva from southern Germany, about 8 mm long

Aedes aegypti larva

Culex larva and pupa

Culex larvae plus one pupa

Electron micrograph of a mosquito egg

text: Pupa

text: As seen in its lateral aspect, the mosquito pupa is comma-shaped. The head and thorax are merged into a cephalothorax, with the abdomen curving around underneath. The pupa can swim actively by flipping its abdomen, and it is commonly called a "tumbler" because of its swimming action. As with the larva, the pupa of most species must come to the surface frequently to breathe, which they do through a pair of respiratory trumpets on their cephalothoraxes. However, pupae do not feed during this stage; typically they pass their time hanging from the surface of the water by their respiratory trumpets. If alarmed, say by a passing shadow, they nimbly swim downwards by flipping their abdomens in much the same way as the larvae do. If undisturbed, they soon float up again.

text: After a few days or longer, depending on the temperature and other circumstances, the pupa rises to the water surface, the dorsal surface of its cephalothorax splits, and the adult mosquito emerges. The pupa is less active than the larva because it does not feed, whereas the larva feeds constantly.[29]

text: Adult

text: The period of development from egg to adult varies among species and is strongly influenced by ambient temperature. Some species of mosquitoes can develop from egg to adult in as few as five days, but a more typical period of development in tropical conditions would be some 40 days or more for most species. The variation of the body size in adult mosquitoes depends on the density of the larval population and food supply within the breeding water.

text: Adult mosquitoes usually mate within a few days after emerging from the pupal stage. In most species, the males form large swarms, usually around dusk, and the females fly into the swarms to mate.

text: Males typically live for about 5–7 days, feeding on nectar and other sources of sugar. After obtaining a full blood meal, the female will rest for a few days while the blood is digested and eggs are developed. This process depends on the temperature, but usually takes two to three days in tropical conditions. Once the eggs are fully developed, the female lays them and resumes host-seeking.

text: The cycle repeats itself until the female dies. While females can live longer than a month in captivity, most do not live longer than one to two weeks in nature. Their lifespans depend on temperature, humidity, and their ability to successfully obtain a blood meal while avoiding host defenses and predators.

text: The length of the adult is typically between 3mm and 6mm.  The smallest known mosquitoes are around 2 mm (0.1 in), and the largest around 19 mm (0.7 in).[31]  Mosquitoes typically weigh around 5 mg. All mosquitoes have slender bodies with three segments: a head, a thorax and an abdomen.

text: The head is specialized for receiving sensory information and for feeding. It has eyes and a pair of long, many-segmented antennae. The antennae are important for detecting host odors, as well as odors of breeding sites where females lay eggs. In all mosquito species, the antennae of the males in comparison to the females are noticeably bushier and contain auditory receptors to detect the characteristic whine of the females.

text: The compound eyes are distinctly separated from one another. Their larvae only possess a pit-eye ocellus. The compound eyes of adults develop in a separate region of the head.[32] New ommatidia are added in semicircular rows at the rear of the eye. During the first phase of growth, this leads to individual ommatidia being square, but later in development they become hexagonal. The hexagonal pattern will only become visible when the carapace of the stage with square eyes is molted.[32]

text: The head also has an elongated, forward-projecting, stinger-like proboscis used for feeding, and two sensory palps. The maxillary palps of the males are longer than their proboscises, whereas the females’ maxillary palps are much shorter. In typical bloodsucking species, the female has an elongated proboscis.

text: The thorax is specialized for locomotion. Three pairs of legs and a pair of wings are attached to the thorax. The insect wing is an outgrowth of the exoskeleton. The Anopheles mosquito can fly for up to four hours continuously at 1 to 2 km/h (0.6–1 mph),[33] traveling up to 12 km (7.5 mi) in a night. Males beat their wings between 450 and 600 times per second.[34]

text: The abdomen is specialized for food digestion and egg development; the abdomen of a mosquito can hold three times its own weight in blood.[35] This segment expands considerably when a female takes a blood meal. The blood is digested over time, serving as a source of protein for the production of eggs, which gradually fill the abdomen.

text: Feeding by adults

text: Typically, both male and female mosquitoes feed on nectar and plant juices, but in many species the mouthparts of the females are adapted for piercing the skin of animal hosts and sucking their blood as ectoparasites. In many species, the female needs to obtain nutrients from a blood meal before it can produce eggs, whereas in many other species, it can produce more eggs after a blood meal. A mosquito has a variety of ways of finding its prey, including chemical, visual, and heat sensors.[36] Both plant materials and blood are useful sources of energy in the form of sugars, and blood also supplies more concentrated nutrients, such as lipids, but the most important function of blood meals is to obtain proteins as materials for egg production.

text: The feeding preferences of mosquitoes include those with type O blood, heavy breathers, those with a lot of skin bacteria, people with a lot of body heat, and the pregnant.[37][38] Individuals' attractiveness to mosquitoes also has a heritable, genetically-controlled component.[39]

text: When a female reproduces without such parasitic meals, it is said to practice autogenous reproduction, as in Toxorhynchites; otherwise, the reproduction may be termed anautogenous, as occurs in mosquito species that serve as disease vectors, particularly Anopheles and some of the most important disease vectors in the genus Aedes. In contrast, some mosquitoes, for example, many Culex, are partially anautogenous: they do not need a blood meal for their first cycle of egg production, which they produce autogenously; however, subsequent clutches of eggs are produced anautogenously, at which point their disease vectoring activity becomes operative.[40]

text: Female mosquitoes hunt their blood host by detecting organic substances such as carbon dioxide (CO2) and 1-octen-3-ol produced from the host, and through visual recognition. Mosquitoes prefer some people over others. The preferred victim's sweat simply smells better than others' because of the proportions of the carbon dioxide, octenol and other compounds that make up body odor.[41] The most powerful semiochemical that triggers the keen sense of smell of Culex quinquefasciatus is nonanal.[42] Another compound identified in human blood that attracts mosquitoes is sulcatone or 6-methyl-5-hepten-2-one, especially for Aedes aegypti mosquitoes with the odor receptor gene Or4.[43] A large part of the mosquito’s sense of smell, or olfactory system, is devoted to sniffing out blood sources. Of 72 types of odor receptors on its antennae, at least 27 are tuned to detect chemicals found in perspiration.[44] In Aedes, the search for a host takes place in two phases. First, the mosquito exhibits a nonspecific searching behavior until the perception of host stimulants, then it follows a targeted approach.[45]

text: Most mosquito species are crepuscular (dawn or dusk) feeders. During the heat of the day, most mosquitoes rest in a cool place and wait for the evenings, although they may still bite if disturbed.[46] Some species, such as the Asian tiger mosquito, are known to fly and feed during daytime.[47]

text: Prior to and during blood feeding, blood-sucking mosquitoes inject saliva into the bodies of their source(s) of blood. This saliva serves as an anticoagulant; without it the female mosquito's proboscis might become clogged with blood clots. The saliva also is the main route by which mosquito physiology offers passenger pathogens access to the hosts' bloodstream. The salivary glands are a major target to most pathogens, whence they find their way into the host via the saliva.

text: A mosquito bite often leaves an itchy weal, a raised bump, on the victim's skin, which is caused by histamines trying to fight off the protein left by the attacking insect.[48]

text: Mosquitoes of the genus Toxorhynchites never drink blood.[49] This genus includes the largest extant mosquitoes, the larvae of which prey on the larvae of other mosquitoes. These mosquito eaters have been used in the past as mosquito control agents, with varying success.[50]

text: Hosts of blood-feeding mosquito species

text: Many, if not all, blood-sucking species of mosquitoes are fairly selective feeders that specialise in particular host species, though they often relax their selectivity when they experience severe competition for food, defensive activity on the part of the hosts, or starvation. Some species feed selectively on monkeys, while others prefer particular kinds of birds, but they become less selective as conditions become more difficult. For example, Culiseta melanura sucks the blood of passerine birds for preference, and such birds are typically the main reservoir of the Eastern equine encephalitis virus in North America. Early in the season while mosquito numbers are low, they concentrate on passerine hosts, but as mosquito numbers rise and the birds are forced to defend themselves more vigorously, the mosquitoes become less selective of hosts. Soon the mosquitoes begin attacking mammals more readily, thereby becoming the major vector of the virus, and causing epidemics of the disease, most conspicuously in humans and horses.[51]

text: Even more dramatically, in most of its range in North America, the main vector for the Western equine encephalitis virus is Culex tarsalis, because it is known to feed variously on mammals, birds, reptiles, and amphibians. Even fish may be attacked by some mosquito species if they expose themselves above water level, as mudskippers do.[51][52]

text: Some species of blood-sucking flies, such as many of the Ceratopogonidae, will attack large, live insects and suck their haemolymph[53] and others, such as the so-called "jackal flies" (Milichiidae), will attack the recently dead prey of say, crab spiders (Thomisidae).[54] In 1969 it was reported that some species of anautogenous mosquitoes would feed on the haemolymph of caterpillars.[55] Other observations include mosquitoes feeding on cicadas[56] and mantids.[57] In 2014 it was shown that malaria-transmitting mosquitoes actively seek out some species of caterpillars and feed on their haemolymph,[58] and do so to the caterpillar's apparent physical detriment.[59]

text: Mouthparts

text: Mosquito mouthparts are very specialized, particularly those of the females, which in most species are adapted to piercing skin and then sucking blood. Apart from bloodsucking, the females generally also drink assorted fluids rich in dissolved sugar, such as nectar and honeydew, to obtain the energy they need. For this, their blood-sucking mouthparts are perfectly adequate. In contrast, male mosquitoes are not bloodsuckers; they only drink sugary fluids. Accordingly, their mouthparts do not require the same degree of specialization as those of females.[60]

text: Externally, the most obvious feeding structure of the mosquito is the proboscis. More specifically, the visible part of the proboscis is the labium, which forms the sheath enclosing the rest of the mouthparts. When the mosquito first lands on a potential host, its mouthparts are enclosed entirely in this sheath, and it will touch the tip of the labium to the skin in various places. Sometimes, it will begin to bite almost straight away, while other times, it will prod around, apparently looking for a suitable place. Occasionally, it will wander for a considerable time, and eventually fly away without biting. Presumably, this probing is a search for a place with easily accessible blood vessels, but the exact mechanism is not known. It is known that there are two taste receptors at the tip of the labium which may well play a role.[61]

text: The female mosquito does not insert its labium into the skin; it bends back into a bow when the mosquito begins to bite. The tip of the labium remains in contact with the skin of the victim, acting as a guide for the other mouthparts. In total, there are six mouthparts besides the labium: two mandibles, two maxillae, the hypopharynx, and the labrum.

text: The mandibles and the maxillae are used for piercing the skin. The mandibles are pointed, while the maxillae end in flat, toothed "blades". To force these into the skin, the mosquito moves its head backwards and forwards. On one movement, the maxillae are moved as far forward as possible. On the opposite movement, the mandibles are pushed deeper into the skin by levering against the maxillae. The maxillae do not slip back because the toothed blades grip the skin.

text: The hypopharynx and the labrum are both hollow. Saliva with anticoagulant is pumped down the hypopharynx to prevent clotting, and blood is drawn up the labrum.

text: To understand the mosquito mouthparts, it is helpful to draw a comparison with an insect that chews food, such as a dragonfly. A dragonfly has two mandibles, which are used for chewing, and two maxillae, which are used to hold the food in place as it is chewed. The labium forms the floor of the dragonfly's mouth, the labrum forms the top, while the hypopharynx is inside the mouth and is used in swallowing. Conceptually, then, the mosquito's proboscis is an adaptation of the mouthparts that occur in other insects. The labium still lies beneath the other mouthparts, but also enfolds them, and it has been extended into a proboscis. The maxillae still "grip" the "food" while the mandibles "bite" it. The top of the mouth, the labrum, has developed into a channeled blade the length of the proboscis, with a cross-section like an inverted "U". Finally, the hypopharynx has extended into a tube that can deliver saliva at the end of the proboscis. Its upper surface is somewhat flattened so, when pressed against it, the labrum forms a closed tube for conveying blood from the victim.[62]

text: Saliva

text: For the mosquito to obtain a blood meal, it must circumvent the vertebrate's physiological responses. The mosquito, as with all blood-feeding arthropods, has mechanisms to effectively block the hemostasis system with their saliva, which contains a mixture of secreted proteins. Mosquito saliva acts to reduce vascular constriction, blood clotting, platelet aggregation, angiogenesis and immunity, and creates inflammation.[63] Universally, hematophagous arthropod saliva contains at least one anti-clotting, one anti-platelet, and one vasodilatory substance. Mosquito saliva also contains enzymes that aid in sugar feeding,[64] and antimicrobial agents to control bacterial growth in the sugar meal.[65] The composition of mosquito saliva is relatively simple, as it usually contains fewer than 20 dominant proteins.[66] As of the early 2000s[update], scientists still were unable to ascribe functions to more than half of the molecules found in arthropod saliva.[66] One promising application of components of mosquito saliva is the development of anti-clotting drugs, such as clotting inhibitors and capillary dilators, that could be useful for cardiovascular disease.

text: It is now well recognized that feeding ticks, sandflies, and, more recently, mosquitoes, have an ability to modulate the immune response of the animals (hosts) on which they feed.[63] The presence of this activity in vector saliva is a reflection of the inherent overlapping and interconnected nature of the host hemostatic and inflammatory/immunological responses and the intrinsic need to prevent these host defenses from disrupting successful feeding. The mechanism for mosquito saliva-induced alteration of the host immune response is unclear, but the data have become increasingly convincing that such an effect occurs. Early work described a factor in saliva that directly suppresses TNF-α release, but not antigen-induced histamine secretion, from activated mast cells.[67] Experiments by Cross et al. (1994) demonstrated that the inclusion of Ae. aegypti mosquito saliva into naïve cultures led to a suppression of interleukin (IL)-2 and IFN-γ production, while the cytokines IL-4 and IL-5 are unaffected.[68] Cellular proliferation in response to IL-2 is clearly reduced by prior treatment of cells with mosquito salivary gland extract.[68] Correspondingly, activated splenocytes isolated from mice fed upon by either Ae. aegypti or Cx. pipiens mosquitoes produce markedly higher levels of IL-4 and IL-10 concurrent with suppressed IFN-γ production.[69] Unexpectedly, this shift in cytokine expression is observed in splenocytes up to 10 days after mosquito exposure, suggesting natural feeding of mosquitoes can have a profound, enduring, and systemic effect on the immune response.[69]

text: T cell populations are decidedly susceptible to the suppressive effect of mosquito saliva, showing increased mortality and decreased division rates.[70] Parallel work by Wasserman et al. (2004) demonstrated that T and B cell proliferation was inhibited in a dose dependent manner with concentrations as low as 1/7 of the saliva in a single mosquito.[71] Depinay et al. (2005) observed a suppression of antibody-specific T cell responses mediated by mosquito saliva and dependent on mast cells and IL-10 expression.[72]

text: A 2006 study suggests mosquito saliva can also decrease expression of interferon−α/β during early mosquito-borne virus infection.[73] The contribution of type I interferons (IFN) in recovery from infection with viruses has been demonstrated in vivo by the therapeutic and prophylactic effects of administration of IFN inducers or IFN itself,[74] and different research suggests mosquito saliva exacerbates West Nile virus infection,[75] as well as other mosquito-transmitted viruses.[76]

text: Studies in humanized mice bearing a reconstituted human immune system have suggested potential impact of mosquito saliva in humans. Work published in 2018 from the Baylor College of Medicine using such humanized mice came to several conclusions, among them being that mosquito saliva led to an increase in natural killer T cells in peripheral blood; to an overall decrease in ex vivo cytokine production by peripheral blood mononuclear cells (PBMCs); changes to proportions of subsets of PBMCs; changes in the prevalence of T cell subtypes across organs; and changes to circulating levels of cytokines.[77]

text: Egg development and blood digestion

text: Female mosquitoes use two very different food sources. They need sugar for energy, which is taken from sources such as nectar, and they need blood as a source of protein for egg development. Because biting is risky and suitable hosts may be difficult to find, mosquitoes take as much blood as possible when they have the opportunity.[citation needed] Digesting large volumes of blood takes time, requiring the use of energy from sugars during the feeding process.[citation needed] To avoid this problem, mosquitoes possess a digestive system which can store both food types, giving access to both as needed.[citation needed] When the mosquito drinks a sugar solution, it is directed to a crop. The crop can release sugar into the stomach as it is required. At the same time, the stomach never becomes full of sugar solution, which would prevent the mosquito taking a blood meal.[citation needed] Blood is directed straight into the mosquito's stomach. In species that feed on mammalian or avian blood, hosts whose blood pressure is high, the mosquito feeds selectively from active blood vessels, where the pressure assists in filling the gut rapidly.[citation needed]

text: Upon completion of feeding, the mosquito will withdraw her proboscis, and as the gut fills up, the stomach lining secretes a peritrophic membrane that surrounds the blood. This membrane keeps the blood separate from anything else in the stomach. However, like certain other insects that survive on dilute, purely liquid diets, notably many of the Hemiptera, many adult mosquitoes must excrete unwanted aqueous fractions even as they feed. (See the photograph of a feeding Anopheles stephensi: Note that the excreted droplet patently is not whole blood, being far more dilute). As long as they are not disturbed, this permits mosquitoes to continue feeding until they have accumulated a full meal of nutrient solids. As a result, a mosquito replete with blood can continue to absorb sugar, even as the blood meal is slowly digested over a period of several days.[61][78] Once blood is in the stomach, the midgut of the female synthesizes proteolytic enzymes that hydrolyze the blood proteins into free amino acids. These are used as building blocks for the synthesis of egg yolk proteins.

text: In the mosquito Anopheles stephensi Liston, trypsin activity is restricted entirely to the posterior midgut lumen. No trypsin activity occurs before the blood meal, but activity increases continuously up to 30 hours after feeding, and subsequently returns to baseline levels by 60 hours. Aminopeptidase is active in the anterior and posterior midgut regions before and after feeding. In the whole midgut, activity rises from a baseline of approximately three enzyme units (EU) per midgut to a maximum of 12 EU at 30 hours after the blood meal, subsequently falling to baseline levels by 60 hours. A similar cycle of activity occurs in the posterior midgut and posterior midgut lumen, whereas aminopeptidase in the posterior midgut epithelium decreases in activity during digestion. Aminopeptidase in the anterior midgut is maintained at a constant, low level, showing no significant variation with time after feeding. Alpha-glucosidase is active in anterior and posterior midguts before and at all times after feeding. In whole midgut homogenates, alpha-glucosidase activity increases slowly up to 18 hours after the blood meal, then rises rapidly to a maximum at 30 hours after the blood meal, whereas the subsequent decline in activity is less predictable. All posterior midgut activity is restricted to the posterior midgut lumen. Depending on the time after feeding, greater than 25% of the total midgut activity of alpha-glucosidase is located in the anterior midgut. After blood meal ingestion, proteases are active only in the posterior midgut. Trypsin is the major primary hydrolytic protease and is secreted into the posterior midgut lumen without activation in the posterior midgut epithelium. Aminoptidase activity is also luminal in the posterior midgut, but cellular aminopeptidases are required for peptide processing in both anterior and posterior midguts. Alpha-glucosidase activity is elevated in the posterior midgut after feeding in response to the blood meal, whereas activity in the anterior midgut is consistent with a nectar-processing role for this midgut region.[79]

text: Distribution

text: In the sense of the entire family Culicidae, mosquitoes are cosmopolitan; in every land region except for Antarctica[61] and a few islands, mainly in polar or subpolar climates, at least some species of mosquito will be present. Iceland is such an island, being essentially free of mosquitoes.[80]  In warm and humid tropical regions, some mosquito species are active for the entire year, but in temperate and cold regions they hibernate or enter diapause. Arctic or subarctic mosquitoes, like some other arctic midges in families such as Simuliidae and Ceratopogonidae may be active for only a few weeks annually as melt-water pools form on the permafrost. During that time, though, they emerge in huge numbers in some regions and may take up to 300 ml of blood per day from each animal in a caribou herd.[81]

text: The absence of mosquitoes from Iceland and similar regions is probably because of quirks of their climate, which differs in some respects from mainland regions. At the start of the uninterrupted continental winter of Greenland and the northern regions of Eurasia and America, the pupa enters diapause under the ice that covers sufficiently deep water. The imago ecloses only after the ice breaks in late spring. In Iceland however, the weather is less predictable. In mid-winter it frequently warms up suddenly, causing the ice to break, but then to freeze again after a few days. By that time the mosquitoes will have emerged from their pupae, but the new freeze sets in before they can complete their life cycle. Any anautogenous adult mosquito would need a host to supply a blood meal before it could lay viable eggs; it would need time to mate, mature the eggs and oviposit in suitable wetlands. These requirements would not be realistic in Iceland and in fact the absence of mosquitoes from such subpolar islands is in line with the islands' low biodiversity; Iceland has fewer than 1,500 described species of insects, many of them probably accidentally introduced by human agency. In Iceland most ectoparasitic insects live in sheltered conditions or actually on mammals; examples include lice, fleas and bedbugs, in whose living conditions freezing is no concern, and most of which were introduced inadvertently by humans.[80]

text: Some other aquatic Diptera, such as Simuliidae, do survive in Iceland, but their habits and adaptations differ from those of mosquitoes; Simuliidae for example, though they, like mosquitoes, are bloodsuckers, generally inhabit stones under running water that does not readily freeze and which is totally unsuited to mosquitoes; mosquitoes are generally not adapted to running water.[82][83]

text: Eggs of species of mosquitoes from the temperate zones are more tolerant of cold than the eggs of species indigenous to warmer regions.[84][85] Many even tolerate subzero temperatures. In addition, adults of some species can survive the winter by taking shelter in suitable microhabitats such as buildings or hollow trees.[86]

text: Means of dispersal

text: Worldwide introduction of various mosquito species over large distances into regions where they are not indigenous has occurred through human agencies, primarily on sea routes, in which the eggs, larvae, and pupae inhabiting water-filled used tires and cut flowers are transported. However, apart from sea transport, mosquitoes have been effectively carried by personal vehicles, delivery trucks, trains, and aircraft. Man-made areas such as storm water retention basins, or storm drains also provide sprawling sanctuaries. Sufficient quarantine measures have proven difficult to implement. In addition, outdoor pool areas make a perfect place for them to grow.

text: Disease

text: Mosquitoes can act as vectors for many disease-causing viruses and parasites. Infected mosquitoes carry these organisms from person to person without exhibiting symptoms themselves.[citation needed] Mosquito-borne diseases include:

text:
Viral diseases, such as yellow fever, dengue fever, and chikungunya, transmitted mostly by Aedes aegypti. Dengue fever is the most common cause of fever in travelers returning from the Caribbean, Central America, South America, and South Central Asia. This disease is spread through the bites of infected mosquitoes and cannot be spread person to person. Severe dengue can be fatal, but with good treatment, fewer than 1% of patients die from dengue.[87] Work published in 2012 from Baylor College of Medicine suggested that for some diseases, such as dengue fever, which can be transmitted via mosquitoes and by other means, the severity of the mosquito-transmitted disease could be greater.[88]
The parasitic diseases collectively called malaria, caused by various species of Plasmodium, carried by female mosquitoes of the genus Anopheles
Lymphatic filariasis (the main cause of elephantiasis) which can be spread by a wide variety of mosquito species[89]
West Nile virus is a concern in the United States, but there are no reliable statistics on worldwide cases.
Eastern equine encephalitis virus is a concern in the eastern United States.
Tularemia, a bacterial disease caused by Francisella tularensis, is variously transmitted, including by biting flies. Culex and Culiseta are vectors of tularemia, as well as arbovirus infections such as West Nile virus.[90]
Zika, recently notorious, though rarely deadly. It causes fever, joint pain, rashes and conjunctivitis. The most serious consequence appears when the infected person is a pregnant woman, since during pregnancy this virus can originate a birth defect called microcephaly.

text: Potential transmission of HIV was originally a public health concern, but practical considerations and detailed studies of epidemiological patterns suggest that any transmission of the HIV virus by mosquitoes is at worst extremely unlikely.[91]

text: Various species of mosquitoes are estimated to transmit various types of disease to more than 700 million people annually in Africa, South America, Central America, Mexico, Russia, and much of Asia, with millions of resultant deaths. At least two million people annually die of these diseases, and the morbidity rates are many times higher still.

text: Methods used to prevent the spread of disease, or to protect individuals in areas where disease is endemic, include:

text:
Vector control aimed at mosquito control or eradication
Disease prevention, using prophylactic drugs and developing vaccines
Prevention of mosquito bites, with insecticides, nets, and repellents

text: Since most such diseases are carried by "elderly" female mosquitoes, some scientists have suggested focusing on these to avoid the evolution of resistance.[92]

text: Urban ecology

text: A recent study collected and identified 20,551 adult female mosquitoes in five neighborhoods of the city of Baltimore over 2 years. Most of these mosquitos (73%) were invasive Asian tiger mosquitoes (Aedes albopictus), but samples also included Culex (24%) and Aedes japonicus (2.4%) mosquitoes, both of which carry West Nile virus.  The hosts of these mosquitos were determined by isolating DNA from the former. Invasive brown rats made up 71.7% of all Asian tiger blood meals. By contrast, birds were the most common victims of Culex, while Aedes appears to avoid birds altogether. Humans and cats each made up 13.3 percent of Aedes blood meals, while deer and dogs were bitten less frequently by all mosquito species. Notably, the study showed that different neighborhoods in Baltimore had different abundances and composition of mosquito species, dependent on the abundance of neglected containers for mosquito breeding, and how people choose to spend time outside.[93]

text: Control

text: Many measures have been tried for mosquito control, including the elimination of breeding places, exclusion via window screens and mosquito nets, biological control with parasites such as fungi[94][95] and nematodes,[96] or predators such as fish,[97][98][99] copepods,[100] dragonfly nymphs and adults, and some species of lizard and gecko.[101] Another approach is to introduce large numbers of sterile males.[102] Genetic methods including cytoplasmic incompatibility, chromosomal translocations, sex distortion and gene replacement have been explored. They are cheaper and not subject to vector resistance.[103]

text: Repellents

text: Insect repellents are applied on skin and give short-term protection against mosquito bites. The chemical DEET repels some mosquitoes and other insects.[104] Some CDC-recommended repellents are picaridin, eucalyptus oil (PMD) and IR3535.[105] Others are indalone, dimethyl phthalate, dimethyl carbate, and ethyl hexanediol.

text: In 2015, researchers at New Mexico State University tested 10 commercially available products for their effectiveness at repelling mosquitoes.[106] On the mosquito Aedes aegypti, the vector of Zika virus, only one repellent that did not contain DEET had a strong effect for the duration of the 240 minutes test: a lemon eucalyptus oil repellent. All DEET-containing mosquito repellents were active.

text: There are also electronic insect repellent devices which produce ultrasounds that were developed to keep away insects (and mosquitoes). However, no scientific research based on the EPA's and many universities' studies has ever provided evidence that these devices prevent a human from being bitten by a mosquito.[107][108] In 2005, the British consumer magazine Holiday reported the results of its test of a range of mosquito deterrents. The magazine's editor Lorna Cowan described the four appliances that used a buzzer as "a shocking waste of money" which "should be removed from sale".[109]

text: Bites and treatment

text:
Visible, irritating bites are due to an immune response from the binding of IgG and IgE antibodies to antigens in the mosquito's saliva. Some of the sensitizing antigens are common to all mosquito species, whereas others are specific to certain species. There are both immediate hypersensitivity reactions (types I and III) and delayed hypersensitivity reactions (type IV) to mosquito bites.[110] Both reactions result in itching, redness and swelling. Immediate reactions develop within a few minutes of the bite and last for a few hours. Delayed reactions take around a day to develop, and last for up to a week.
Several anti-itch medications are commercially available, including those taken orally, such as diphenhydramine, or topically applied antihistamines and, for more severe cases, corticosteroids, such as hydrocortisone and triamcinolone. A common topical remedy in camping gear is aqueous ammonia.

text: In human culture

text: Ancient Greek beast fables including "The Elephant and the Mosquito" and "The Bull and the Mosquito", with the general moral that the large beast does not even notice the small one, derive ultimately from Mesopotamia.[111]

text: Winsor McCay's 1912 film How a Mosquito Operates was one of the earliest works of animation, far ahead of its time in technical quality. It depicts a giant mosquito tormenting a sleeping man.[112]

text: The de Havilland Mosquito was a high-speed aircraft manufactured between 1940 and 1950, and used in many roles.[113]

text: Notes

text: Jump up ^ The plural can also be written "mosquitos".

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