76 American Midland Naturalist Monograph No. 3 



Oklahoma (159); Pennsylvania (8); Rhode Island (99); South Dakota 

 (128); Texas (108); Wisconsin (48). 



bionomics. — The females are active feeders on man and wild and do- 

 mesticated animals. The adults are active principally at night and rest in 

 dark corners in buildings, underneath houses, in hollow trees and other 

 shelters during daylight hours. They are very active for a short period after 

 dusk but their activities are probably limited to flights in search of a blood 

 meal during the remainder of the night except for another active period at 

 dawn when they shift to daytime resting places. The effective flight range 

 of this species varies, depending on the proximity to suitable hosts upon 

 which they can feed and the number produced, but it is usually regarded as 

 approximately one mile under average conditions. Anopheles quadrimaculatus 

 breeds mostly in fresh-water in sluggish streams, canals, ponds and lakes 

 with surface-growing or emergent vegetation or floating debris. 



medical importance. — The susceptibility of this species to experimen- 

 tal infection with Plasmodium vivax, P. falciparum and P. malariae has 

 been well established and infections in nature have been found by numerous 

 workers. This mosquito is regarded as the most important vector of malaria 

 in the United States. 



Anopheles (Anopheles) walkeri Theobald 



Anopheles n.a/^en Theobald, 1901. Mon. Culic, 1:199. 



ADULT FEMALE. — Medium-sized species. Head: Proboscis long, dark; palpi 

 about as long as proboscis, dark-scaled except for a narrow white ring at apex 

 of each segment (Fig. 39E). Occiput clothed with dark erect forked scales; 

 the vertex with a few pale recumbent scales; frontal tuft dark. Thorax: Inte- 

 gument of scutum dark-brown, clothed with short golden-brown to dark- 

 brown hairs. Abdomen: Integument dark-brown to black, clothed with yellow 

 to brown hairs. Legs: Legs entirely dark-scaled except for white knee spots. 

 Wing: Scales narrow, entirely dark; some of the scales arranged to form 

 four darker spots, more or less distinct (Fig. 39F) . Halter: Knob of halter 

 pale scaled (Fig. 39D). 



ADULT MALE. — Coloration similar to that of female, terminalia (Fig. 

 39). — Ninth tergite (IX-T) a narrow, moderately sclerotized band; lobes 

 (IXT-L) lateral in position, slender, tapered, pointed or rounded at tip. 

 Tenth stermte absent; anal lobe (An-L) large, triangular, spiculate. Phallo- 

 some (Ph) cylindrical, furcate at base; apiex with 3 to 5 pairs of ligulate 

 leaflets (Ph-L), the ante-apical pair more than half as long as the apical 

 pair (usually about three-fourths as long) ; none of the leaflets with short, 

 coarse basal teeth. Claspette broad, fleshy, consisting of a dorsal lobe (Cl-DL) 

 and a ventral lobe (Cl-VL) . Dorsal lobe apically with one or two large, 

 blunt, often slightly capitate spines; ventral lobe with a large, pointed spine 

 at ap>ex and a long sub-apical spine. Basistyle (Bs) conical, about twice as 

 long as broad, rounded apically, clothed with long setae and few or no scales; 



