The influence of size and source of blood meals on rate of digestion of vertebrate serum proteins in mosquitoes (Diptera: Culicidae).

An understanding of the factors involved in the digestion of blood in mosquitoes has value in studies of the feeding habits of these insects and in considerations of their roles as vectors of pathogens. When sources of blood meals are to be determined by the serological precipitin test, it is often important to know the rate at which blood proteins reach such a stage of digestion that they no longer precipitate with their specific antibodies. Studies with various species of haematophagous insects have shown that the rate of digestion of serum proteins and other blood-meal com ponents is influenced by temperature (Shlenova, 1938; West and Eligh, 1952; Downe, 1957a), light (O'Gower, 1956) and probably humidity (Shlenova, op. cit.). Differences in rate of digestion among different species of mosquitoes also have been reported (de Buck et al., 1932 ; O'Gower, 1956). There is little precise information on the effects of size or source of blood meals on rate of digestion, although Shambaugh (1954) correlated the amount of blood ingested with midgut protease in Aedes aegypti (L.). There is evidence that the source of the blood meal and the quantity of blood ingested influences the number of eggs produced in mosquitoes (Woke et al., 1956; Woke, 1937; Colless and Chellapah, 1960). Egg production is often regarded as the culmination of metabolic processes following the ingestion of a blood meal (cf. Christophers, 1960). This report describes precipitin-test studies on rate of digestion of serum proteins of blood meals in six species of mosquitoes. Investiga tions relating to the influence of size and source of blood meals on rate of digestion are described.