Psorophora howardii

Distinguished from other Psorophora species by combination of large size, shaggy legs, and specific scale patterns: broad grayish-white head scales with median bare stripe, dark thorax, and white abdominal median patch. Proboscis and palpi proportions also diagnostic. DNA barcoding of COI gene can confirm morphological identification.

Floodwater habitats including rain pools, grassy ditches, woodland pools, and agricultural depressions prone to flooding. In Florida, documented in citrus furrow irrigation systems where females oviposit low in furrows. Larvae occur in unshaded or partly shaded temporary rain-filled pools.

Native to tropical and subtropical Americas: southern United States, Mexico, Caribbean Islands, Central America (Costa Rica, El Salvador, Guatemala, Nicaragua), and South America (Brazil, Cuba, Lesser Antilles). Previous northern limit approximately 40.5°N (central Indiana). Recent northward expansion documented in Pennsylvania (~40.6°N), New York (~40.9°N), Iowa (~41.6°N), and first Canadian record in Windsor-Essex County, Ontario (~42.2–42.3°N) in September 2024.

Larvae occur from March to October. Adults active year-round in southern range; seasonal in northern expanded range.

Larvae are predaceous, feeding on other mosquito larvae. Adult females are aggressive blood-feeders on medium to large mammals including humans.

• humans - blood-feeding hostpersistent biter, attacks at any time of day
• medium to large mammals - blood-feeding host

Floodwater mosquito; females oviposit in dirt depressions prone to flooding. Eggs hatch following rainfall or irrigation flooding. Immature development occurs in temporary aquatic habitats. Larval stage predaceous.

Adult females are notoriously aggressive blood-feeders that readily attack humans. Persistent biters active at any time of day. Proboscis capable of piercing multiple layers of clothing including coat, vest, and two shirts. Larvae are predatory, capturing prey through rapid neck extension to launch head toward prey—a fixed-action pattern strike taking approximately 15 milliseconds.

Predatory mosquito species during larval stage; may regulate populations of floodwater Aedes mosquitoes through larval predation.

Significant nuisance pest due to aggressive biting behavior and ability to pierce clothing. Potential disease vector; noted as capable of spreading West Nile virus, though specific vector competence studies for this species remain unstudied. Range expansion into new regions may increase human exposure.

• Psorophora ciliataBoth are large predatory floodwater mosquitoes with aggressive biting behavior; P. ciliata distinguished by different scale patterns and distribution more common in eastern United States
• Psorophora feroxBoth are floodwater Psorophora species with recent northward range expansion; P. ferox has different abdominal scale patterns and slightly smaller size
• Aedes vexansShares floodwater habitat and aggressive biting behavior; distinguished by smaller size, different larval predation strategy (non-predaceous or facultative), and lack of shaggy leg scaling

• mosquito
• floodwater mosquito
• predatory larvae
• aggressive biter
• vector
• range expansion
• invasive potential

• BugGuide
• Wikipedia
• GBIF taxonomy match
• iNaturalist taxon
• NCBI Taxonomy
• Catalogue of Life
• Harpoon Heads, Sweeping Tails: How Predatory Mosquito Larvae Capture Prey
• Mosquito Management in the Era of Extreme Weather
• The Best of 2022 on Entomology Today
• New record of Psorophora howardii (Diptera: Culicidae) in Southern Ontario, Canada.