SERUM COMPOSITION OF AEDES-AEGYPTI (DIPTERA, CULICIDAE) LARVAE AND THE PRODUCTION OF AN OVIPOSITION REPELLENT ARE INFLUENCED BY INFECTION WITH THE ENTOMOPATHOGENIC DIGENEAN PLAGIORCHIS ELEGANS (TREMATODA, PLAGIORCHIIDAE), STARVATION, AND CROWDING

Subjecting Aedes aegypti (L.) larvae to conditions that induced the pr oduction of oviposition repellency also reduced their wet and dry weig hts and the concentration of total serum carbohydrates, amino acids, a nd proteins. Thus, infection with metacercariae of the entomopathogeni c digenean Plagiorchis elegans (Rudolphi), starvation for 7 d, or crow ding for 2 d reduced larval dry weights by as much as 32, 20, and 23%, respectively, and wet weights by 20, 14, and 11%, respectively. Total serum carbohydrates declined by as much as 36, el, and 29% for infect ed, starved, and crowded larvae, respectively, amino acids by 39, Is, and 48%, and protein concentrations by 72, 63, and 62%, respectively. Repellency dilution titers were cor related inversely with movement of the mouth parts and gut. Incubation of infected, starved, and crowded larvae in 0.01 g/liter glucose greatly reduced the level of repellenc y of their waters, whereas adding glucose to repellent waters had only minor effects. Results indicate that the induction of repellency is a ssociated strongly with nutritional depletion effects.