Western malaria mosquito

Description

Anopheles freeborni, commonly known as the western malaria mosquito, is a species of mosquito in the family Culicidae. It is typically found in the western United States and Canada. Adults are brown to black, with yellow-brown hairs and gray-brown stripes on the thorax. Their scaly wings have four dark spots, which are less distinct in the male. Male Anopheles freeborni aggregate into swarms to attract potential mates. Females are able to overwinter, allowing for seasonal development of eggs in the spring. The western malaria mosquito feeds on bloodmeals. Within the United States’ regions of semiarid or arid climate, it has been historically identified as the primary transmission vector for malaria. It was most notably involved in the malaria outbreaks of northern California during the turn of the 20th century. Adult A. freeborni are medium-sized with overall brown to black coloration. They possess a dark proboscis as well as palpi of similar length to the proboscis on their heads. The head is covered in erect scales, dark-colored at the posterior, yellow-white at the center, and light at the vertex. They also have a frontal tuft composed of several light-colored setae. Adults have a gray-brown prescutellar space and brown to black scutum, which possesses hairs of light yellow to golden-brown coloration. The central area of the scutum has gray-brown stripes and the highest density of hairs. The sickle-shaped scutellum also has similarly-colored hairs and setae. The thorax has setae on the pre-spiracular area, but not on the post-spiracular area. The adult abdomen is brown to black, also with hairs of yellow-brown coloration. Their legs have primarily dark scales, with lighter-colored scales at their tips. They possess wings of about 4.5 mm in length, covered in dark scales, with four spots formed by even darker-colored scales. These spots are less noticeable on males’ wings. The media and radial sector of their wings' backsides have tapered scales, which is unique to the species. The western malaria mosquito is present throughout North America, predominantly in the western United States and British Columbia, Canada. While most common in the United States and Canada, it has also been observed in Mexico. It typically remains west of the Rocky Mountains, but the mosquito has been observed slightly eastward in Texas, New Mexico, and southern Colorado.