Mosquito larvae and associated macroorganisms occurring in gem pits in southern Tha Mai District, Chanthaburi Province, Thailand.

Aquatic field studies were conducted in Tha Mai District, Chanthaburi Province, Thailand. Larval habitats of Anopheles dirus were examined from November 1986 through June 1988 in 42 manmade gem pits. Larvae were found in pits containing clear water under full or partial shade. The abundance of different kinds of mosquito larvae were related to seasonal changes in these aquatic habitats. Variations in An. dirus density and occurrence were related to predators populations, ie Notonectidae and fish.

Anopheles dirus size and fecundity: relationship to larval density and protein accumulation.

Anopheles dirus were reared at two different larval densities (100/pan and 400/pan) to produce two different size classes of adults. Both the wing length and fecundity of females from the two densities were significantly different (p less than 0.001). Adult size was related to larval density and protein accumulation during immature life. Egg production was also related to adult size. Consequently, larger field adults have the potential to live longer and produce more eggs. The smaller adult size associated with crowded larval development was apparently caused by space associated effect on feeding rather than by a shortage of food per se.