It should come as no surprise to anyone to read there are lots of mosquitoes flying around. We tend to think of all mosquitoes as identical, but that’s far from true. While the mosquito’s basic body design has remained the same since the age of the dinosaur, the insect has evolved to fit environments all over the planet. Nowadays there are some three thousand species of mosquito. The number of genera (plural of genus) assigned to mosquitoes varies widely in the telling. Some are still being debated, and some are related to extinct fossil species. Of the three thousand living species, about a hundred and fifty can be found in North America. New Jersey, for example, has been called the “Mosquito State,” because over sixty species live there alone. Let’s acquaint ourselves with the enemy, shall we?
The General of Mosquitoes Worldwide
Aedes albopictus, also present in Mexico and the U.K. among many other countries, appears to have migrated here from north Asia in a shipment of used tires. Albopictus is a key vector for dengue, and a potential vector for many other arboviral diseases. This little monster could be a real problem for Americans in the very near future
Aedes vexans nipponii, also present in Canada, Mexico, and the U.K. among many other countries, is a carrier of Japanese encephalitis.
Anopheles albimanus, also present in Mexico, is a vector for malaria. Not fun.
Anopheles atropos is a vector for West Nile, as are barberi, bradleyi, crucians, franciscanus, and freeborni. Anopheles crucians is also present in Mexico.
Entomologist Wayne J. Crans believes Coquillettidia perturbans, also present in Canada and Mexico, is the prime vector to horses for eastern equine encephalitis.
Culex abominator is a vector for West Nile, as are coronator, erraticus, erythrothorax, nigripalpus, pipiens, quinquefasciatus, restuans, salinarius, stigmatosoma, tarsalis, territans, and thriambus. In all, there are thirty-two Culex species present in the United States.
Culex tarsalis is the most important arboviral vector in western North America. Entomologist William Reisen believes tarsalis is “responsible for maintenance, amplification, and epidemic transmission of St. Louis and western equine encephalitis…This species is also a vector of Llano Seco, Turlock, Gay Lodge, and Hart Park viruses, and several species of avian malaria.” Who wants to party with this guy? Anyone? Anyone?
Four of the eight American species in Culiseta have been found to carry West Nile virus: impatiens, inornata, melanura, and morsitans. Culiseta melanura appears to be a prime vector to birds for eastern equine encephalitis. Alaskaensis, impatiens, and morsitans are also present in Canada. Particeps is also present in Mexico.
Culiseta incidens is a vector for western equine encephalitis.
Culiseta inornata is a vector for western equine encephalitis as well, and populations in North Dakota and Utah have been found to be infected with Cache virus.
Of the three American species in this genus, only Deinocerites cancer, present also in Mexico, has been found to carry West Nile virus.
Haemagogus equinus, present also in Mexico, is a vector for yellow fever in Central America.
Mansonia dyari, present also in Mexico, is fairly benign, preferring birds for its blood meals.
Mansonia tittilans, however, is a vector for West Nile in the U.S. and Mexico. It also carries Venezuelan equine encephalitis, lymphatic filariasis, and dog heartworm, which occasionally infects human beings.
Some seventy species from this genus are present in the United States. Of these, twenty-two carry West Nile: atlanticus, atropalpus, canadensis, cantator, condolescens, dorsalis, dupreei, fitchii, fulvus pallens, grossbecki, infirmatus, japonicus, melanimon, nigromaculis, provocans, sollicitans, squamiger, sticticus, stimulans, taeniorhynchus, triseriatus, and trivittatus. Scientists are still unsure whether any of the species in this genus act as a vector for equine encephalitis, though many have been demonstrated to have the capability of doing so under laboratory conditions.
The three American species in genus Orthopodomyia are alba, kummi, and signifera. Only the latter, present also in Canada and Mexico, has been shown to be a vector for West Nile virus.
There are thirteen American species in genus Psorophora, including the four that have carried West Nile: ciliata, columbiae, ferox, and howardii. All four are present in Mexico, and all but howardii are present in Canada.
This genus is notable for being the only mosquito genus that doesn’t include bloodsuckers. Its adults feed on plant nectar, and the protein they need to create new eggs seems to come entirely from feeding during the larval stage. These are unusually large mosquitoes; their wingspans may exceed twelve millimeters (about half an inch). Toxorhynchites mosquitoes are helpful as biological control agents. There are five Toxorhynchites species in the United States: amboinensis, brevipalpis, rutilus, septentrionalis, and splendens. None are present in Canada or Mexico.
There are four American species in this genus: anhydor, lowii (present also in Mexico), sapphirina, and syntheta. Sapphirina is a carrier for West Nile.
None of the four American species (haynei, mitchellii, smithii, and vanduzeei) in this genus have been shown to be significant disease vectors.
That’s the bunch, at least here in the States. Worldwide, mosquitoes have found their way into nearly every environment; as a matter of fact, there are mosquitoes on every continent but Antarctica.