NITROGEN PARTITIONING AND BLOOD MEAL UTILIZATION BY AEDES-AEGYPTI (DIPTERA-CULICIDAE)

The utilization of the blood meal by mosquitoes was investigated by first feeding females quantities of blood ranging from 1 to 5 mg, and then analyzing the faeces for the various by-products of protein catabolism that were subsequently eliminated. The nitrogeneous waste products in order of importance were uric acid, histidine, ammonia and arginine. Only traces of the other amino acids were excreted. The total amount of each faecal substance varied linearly with the quantity of blood ingested, however their relative proportions did not change. Regardless of blood meal size the quantily of uric acid and ammonia produced indicates that about 80% of the non-histidine and arginine amino acids are deaminated and utilized for metabolic purposes other than egg protein synthesis. Most of the histidine and about one half of the arginine content of the blood were excreted as free amino acids, but the other amino acids were lost in trace amounts. Nineteen per cent of the total ingested amino acids was incorporated into soluble yolk proteins and this proportion was constant even for small blood meals that result in a reduction in the numbers of eggs produced. The comparative aspects of nitrogen partitioning and blood meal utilization by haematophagous insects, as well as the factors that affect blood meal utilization and fecundity in A. aegypti are discussed. © 1979.