Mosquitoes in Central Texas

Common Mosquito Species in Central Texas

Texas A&M AgriLife Extension's Agricultural and Environmental Safety Unit lists 85 documented mosquito species in Texas, organized mainly under the genera Aedes, Anopheles, Culex, and Psorophora, along with several smaller genera. Central Texas residents encounter a working slice of that list, not the full roster, since distribution varies by region and habitat.

Culex quinquefasciatus, the southern house mosquito, is the species Texas A&M's Mosquito Safari program identifies as the most important carrier of West Nile virus and St. Louis encephalitis, particularly in the eastern United States. It prefers to breed in polluted or stagnant water, uses containers readily, and typically stays within about a mile of its breeding site. It favors birds as a host but bites humans as well, often entering homes through unscreened windows or open doors to reach people while they sleep.

Aedes aegypti (the yellow fever mosquito) and Aedes albopictus (the Asian tiger mosquito) are also present. Aedes albopictus was first detected in Texas in 1985 and is now widespread across the state. Anopheles spp. and Psorophora spp. round out the mosquitoes most likely to turn up in Central Texas backyards and green spaces.

Standing Water and the Mosquito Life Cycle

Texas A&M AgriLife Extension's Field Guide to Common Texas Insects splits Texas mosquitoes into two breeding strategies. Standing-water species, including Culex, Anopheles, Coquillettidia, and Culiseta, lay their eggs directly on the water surface in floating masses called rafts. Floodwater species, including Aedes and Psorophora, lay eggs on plants or in moist soil at or below the waterline, where the eggs can sit dormant until flooding triggers hatching.

That dormancy explains why floodwater mosquito eggs hatch on wildly different timelines, anywhere from 16 to 24 hours up to more than two years, according to the same AgriLife guide. Once hatched, larvae molt through several stages over about one week before pupating, and adults emerge 2 to 3 days after that. Adult mosquitoes then live two or more weeks, and standing-water species typically overwinter as mated females.

Mosquitoes do not need much water to complete this cycle. Austin Public Health notes that mosquitoes can breed in as little as one teaspoon of standing water, which is why gutters, plant saucers, buckets, pet dishes, birdbaths, rain barrels, old tires, and children's toys all count as breeding sites, not just ponds or ditches.

Seasonal Activity in Central Texas

Austin Public Health runs a mosquito surveillance program that begins each spring and continues through the warm season, trapping and testing mosquito pools for West Nile virus and posting awareness notices in areas where positive pools turn up. Activity tracks weather: AgriLife Today notes that during dry spells, the pooled water that does remain becomes stagnant and turns into an especially favorable environment for egg laying, so both drought and rain events can drive local mosquito pressure in different ways.

Timing within the day matters as much as timing within the year. AgriLife Today reports that Culex mosquitoes, the primary West Nile virus vector, feed at dusk and throughout the night, with peak activity between 9 p.m. and 2 a.m. That is the biological basis for Austin's public health messaging to limit outdoor exposure specifically around dusk and dawn.

West Nile Virus: Transmission and Risk

The CDC describes West Nile virus as maintained in a cycle between Culex mosquitoes and birds. A mosquito picks up the virus by feeding on an infected bird, then can pass it to a person during a later bite. People are dead-end hosts, meaning an infected person does not carry enough virus in their bloodstream to infect another mosquito that bites them.

Most infections are mild or unnoticed. The CDC states that about 80% of people infected with West Nile virus do not develop symptoms, while about 20% develop flu-like illness, fever, headache, body aches, joint pain, vomiting, diarrhea, or rash, usually starting 2 to 6 days after the bite, though onset can range from 2 to 14 days. Risk of severe, neuroinvasive illness rises with age, and the CDC notes that people 65 and older are three times as likely to develop neurologic illness as younger people. There is no vaccine and no specific antiviral treatment, so care is limited to rest, fluids, and pain relief.

West Nile virus circulates locally on a regular basis, not only in outbreak years. Austin Public Health reported that 41 mosquito pools in Travis County tested positive for West Nile virus in 2025, along with five West Nile virus cases in Austin-Travis County residents that year. By the end of June 2026, at least one additional positive pool had already been identified in the area, in the 78733 zip code, with no human cases confirmed at that point in the season.

Practical Steps to Reduce Mosquito Breeding and Bites

Austin Public Health frames prevention around what it calls the Four Ds, and the EPA's own bite-prevention guidance lines up closely with that framework. Since mosquitoes need so little water to breed, the most effective single action is routine, weekly elimination of standing water around the property.

For water that cannot be drained, such as ornamental ponds, the EPA notes that Bti (Bacillus thuringiensis israelensis) can be applied to kill mosquito larvae without harming other wildlife, as part of a broader integrated pest management approach.

1. Drain standing water outside on a weekly basis, including plant saucers, buckets, clogged gutters, pet dishes, birdbaths, rain barrels, wading pools, and old tires, per Austin Public Health and EPA guidance.
2. Empty and refill birdbaths, fountains, and potted plant trays at least once a week, following the EPA's recommended maintenance schedule.
3. Limit outdoor time at dusk and through the night, when Culex mosquitoes are most active and West Nile virus transmission risk is highest.
4. Wear long sleeves and pants when outdoors, and tuck shirts into pants and pants into socks to close gaps, per EPA guidance.
5. Apply an EPA-registered repellent following label directions, choosing an active ingredient such as DEET, picaridin, oil of lemon eucalyptus, IR3535, para-menthane-diol, or 2-undecanone.
6. Repair or install window and door screens so mosquitoes cannot enter the home, since Culex quinquefasciatus in particular seeks out unscreened openings to reach people indoors.
7. For water features that cannot be drained, use an EPA-registered Bti larvicide product labeled for that use, following label directions.