Which Psorophora species is described as an important pest and where is it found?

• A. Ps. coloumbiae; arid regions of Southern California in irrigated pastures and date groves
• B. Ps. ciliata; tropical lowlands
• C. Ps. longipalpis; temperate forests
• D. Ps. cyanea; alpine meadows

Answer: (A)

Floodwater breeders in arid, irrigation-influenced landscapes can reach very high numbers and become notable pests due to their aggressive biting. The species Psorophora columbiae is recognized as an important pest in these settings, especially in arid regions of Southern California where irrigated pastures and date groves provide ideal breeding sites. That ecological fit—a floodwater mosquito thriving in irrigated agricultural areas of Southern California—makes this option the best match.

The other scenarios describe different habitats or regions (tropical lowlands, temperate forests, alpine meadows) that are not the typical environments associated with this species’ status as a pest in that geographic area.