![Anopheles Mosquitoes](https://hollomanexterminators.com/images/pestlibrary/anopheles-mosquitoes/featured.webp "featured image") # Anopheles Mosquitoes *Anopheles quadrimaculatus* & *Anopheles freeborni* - [Pest Library](https://hollomanexterminators.com/pest-library) / Mosquitoes Anopheles is the malaria genus, and it holds its whole body differently from every other mosquito here. Adults rest at a steep, head-down angle instead of lying flat, and the larvae lie flat under the water's surface instead of hanging from a breathing tube. It also breeds in clean, vegetated water, not the buckets and gutters the other two genera use. ## Seasonal Timeline Most active at dawn and dusk, willing to bite after dark. The western species overwinters as an adult and can wake for a blood meal during a warm spell as early as January or February, well before the season most people associate with mosquitoes. **Peak, Pacific Northwest, California, Mountain West and Southwest**Aug–Sep JanFebMarAprMayJunJulAugSepOctNovDec Most active at dawn and dusk, willing to bite after dark. The western species overwinters as an adult and can wake for a blood meal during… This genus splits by species. In the West, *Anopheles freeborni* has a documented peak and a documented winter-dormancy pattern. In the East, Midwest and South Central, *Anopheles quadrimaculatus* is active spring through as late as November, but no published seasonal calendar for it is as clear as the one for its western relative. No region-by-region seasonal breakdown was found for the genus. ## Where They're Found A malaria-competent Anopheles species is established in every region of the country, just not the same one everywhere. ***Anopheles quadrimaculatus***, the common malaria mosquito, covers the East, Midwest, South Central and Southeast, historically the most important malaria vector in the eastern United States, with the highest density in the Southeast. ***Anopheles freeborni***, the western malaria mosquito, covers California, the Pacific Northwest, the Mountain West and the Southwest, and was the primary vector in California's historical malaria epidemics. ## Related Pests [ Aedes Mosquitoes ](https://hollomanexterminators.com/pest-library/aedes-mosquitoes) [ Culex Mosquitoes ](https://hollomanexterminators.com/pest-library/culex-mosquitoes) [ Mosquitoes ](https://hollomanexterminators.com/pest-library/mosquitoes) ## Life Cycle Egg to adult runs about two to four weeks depending on temperature, on the slower end for a mosquito. The one detail worth remembering: below about 54 degrees Fahrenheit, larvae simply sink and go dormant rather than dying, so a cold snap can look like a solved problem when it is actually a paused one. ### Egg Laid singly, directly on the water surface, each with tiny floats that keep it from sinking. Unlike Aedes eggs, these do not tolerate drying out at all, and unlike Culex eggs, they are never laid in a connected raft. ### Larva This is the genus's other tell. Anopheles larvae have no rear breathing tube. Instead they lie flat, parallel to the surface, breathing through small openings on the abdomen, unlike the hanging posture of Culex and Aedes larvae. ![Anopheles pupa in clean, vegetated water](https://hollomanexterminators.com/images/pestlibrary/anopheles-mosquitoes/pupa.webp "pupa image") ### Pupa[2](#credit-2) A few days longer than the pupal stage of Culex or Aedes. Non-feeding, same as every mosquito pupa, so larvicides that work by poisoning a feeding larva have no effect here. ![Adult Anopheles mosquito resting at a steep angle](https://hollomanexterminators.com/images/pestlibrary/anopheles-mosquitoes/adult.webp "adult image") ### Adult[3](#credit-3) Medium-sized, brown, with long palps almost as long as the proboscis and, on Anopheles quadrimaculatus, four dark spots on the wings. The resting angle is the field mark to lead with: head down, body in a straight line pointed away from the surface. ## Identification ### The resting angle It is the strongest field mark any of the three mosquito genera has. Most mosquitoes hold the body roughly parallel to the surface. Anopheles instead rests at a steep, distinct angle, head down and abdomen pointed up and away, proboscis, head and body in a straight line. ### Two named species matter ***Anopheles quadrimaculatus***, the common malaria mosquito, actually a group of at least five sibling species that cannot be told apart by eye, is a medium brown mosquito with dark abdominal markings and, on the wings, four small dark spots that give the species its name. ***Anopheles freeborni***, the western malaria mosquito, is lighter brown overall. ### Unusually long palps Both carry unusually long palps, nearly as long as the proboscis itself, longer than the short palps on Culex or Aedes. ### The larvae lie flat In the water, the larvae confirm the genus with a matching tell: no rear breathing tube. They lie flat under the surface film instead of hanging at an angle the way Culex and Aedes larvae do. ### No leg banding on either Neither species shows the light-and-dark leg banding used to key out Culex or Aedes. That identification path simply does not apply to this genus. ## Signs of Infestation ### Look at clean water, not containers Pond and marsh edges with emergent vegetation, slow-moving or stagnant irrigation ditches, rice-field margins, algae-covered pools, and grassy roadside ditches are where this genus breeds, not buckets or gutters. ### Adults resting at an angle Head down is the posture to look for. ### When they bite Dawn, dusk and after-dark biting is the pattern to watch for, consistent with both named US species. ### A warm-spell burst in the West In the West specifically, watch for a burst of biting activity during an unseasonably warm spell in January or February. That is overwintering Anopheles freeborni adults waking up for an early blood meal, not a sign of a new infestation. ## Prevention and When to Call a Pro ### Cut the vegetation and algae Reduce vegetation and algae where larvae concentrate, in a pond, ditch or slow-moving water feature on the property. This genus's larvae favor clean, vegetated, often sunlit water, so clearing algal mats and dense emergent plants is a real control lever here in a way it is not for container-breeding species. ### This is not a container job This is not a container-dumping job. A homeowner near agricultural irrigation, a pond, or a marsh cannot simply drain the source the way they can a bucket, which makes this genus more of a call-a-professional-or-district situation than the other two. ### Bti still applies to the larvae Bti still applies to the larval stage the same way it does for Culex and Aedes, since Anopheles larvae feed on suspended algae and organic matter and the mechanism is the same stomach-poison action. ### Screens, timing and repellents Screens, timing around dawn and dusk, and standard repellents (DEET, picaridin, oil of lemon eucalyptus) apply here without any genus-specific change. ### Call your vector control district Call your county mosquito and vector control district for a water source you cannot personally drain: a pond edge, an irrigation ditch, or a neighboring field. Larval surveillance on shared water is their job, not a homeowner's. ## Frequently Asked Questions ### Do we still have malaria mosquitoes in the US? Yes. The malaria-carrying genus, Anopheles, is present across the country, but endemic malaria transmission was eliminated in the early 1950s. Locally acquired cases are rare and occasional. The most recent was a 2023 outbreak of 10 cases across four states, the first in 20 years. ### How can I tell if a mosquito is a malaria mosquito? The clearest sign is how it rests. Anopheles mosquitoes hold their body at a steep angle, head down and abdomen up, while most other mosquitoes rest roughly parallel to the surface. ### Where do malaria mosquitoes breed? Unlike the container-breeding mosquitoes behind Zika and dengue, Anopheles larvae prefer clean, vegetated, often sunlit standing water: pond and marsh edges, irrigation ditches, and slow streams, not buckets or gutters. ### Are malaria mosquitoes the same as the ones that spread West Nile virus? No. Culex mosquitoes are the primary US West Nile vector. Whether Anopheles plays any real role in West Nile transmission is disputed between sources, and it is not considered a significant vector for that disease. ### How far do malaria mosquitoes travel from where they hatch? It depends on the species. The eastern Anopheles quadrimaculatus generally stays within about a mile of its breeding site, while the western Anopheles freeborni has been recorded dispersing up to 10 miles. ## Sources 1. [Common Malaria Mosquito, Anopheles quadrimaculatus Say](https://ask.ifas.ufl.edu/publication/in791) University of Florida IFAS Extension, EENY-491/IN791 2. [Anopheles quadrimaculatus, North American Malaria Mosquito](https://www.lsuagcenter.com/articles/page1757011049218) LSU AgCenter, Publication P4013 3. [Life Cycle of Anopheles Mosquitoes](https://www.cdc.gov/mosquitoes/about/life-cycle-of-anopheles-mosquitoes.html) Centers for Disease Control and Prevention 4. [CDC Operational Guidance for Investigating Locally Acquired Mosquito-Transmitted Malaria, United States, 2026](https://www.cdc.gov/mmwr/volumes/75/rr/rr7501a1.htm) Centers for Disease Control and Prevention, MMWR Recommendations and Reports 75(1) 5. [Guide to Important Mosquitoes in California](https://www.cdph.ca.gov/Programs/CID/DCDC/CDPH%20Document%20Library/GuidetoImportantMosquitoesinCA.pdf) California Department of Public Health, Vector-Borne Disease Section 6. [Mosquitoes, AZ1221](https://acis.cals.arizona.edu/ipm-assessment/mosquitoes) University of Arizona Cooperative Extension, College of Agriculture and Life Sciences ### Image Credits 1. Image: NPMA. Used under NPMA member image license. 2. Image: Steffen Dietzel, via Wikimedia Commons. Public domain. 3. Image: James Gathany, CDC, Public Health Image Library, via Wikimedia Commons. Public domain. ## Related Pests [ Aedes Mosquitoes ](https://hollomanexterminators.com/pest-library/aedes-mosquitoes) [ Culex Mosquitoes ](https://hollomanexterminators.com/pest-library/culex-mosquitoes) [ Mosquitoes ](https://hollomanexterminators.com/pest-library/mosquitoes)