Functional relationships between free amino acids in the hemolymph of fourth instar larvae of the mosquito Aedes aegypti (Diptera, Culicidae) as a basis for toxicological studies.

Characteristic correlations reflecting particular metabolic interactions between free amino acids have been pointed out and used as a sensitive test for the detection of biochemical intoxication symptoms in fourth instar larvae of the mosquito Aedes aegypti exposed for 0-8, 12, 24, and 36 hr to various doses of Bacillus thuringiensis delta-endotoxin ranging from 0.01 to 1 mg liter-1. In a first pool, serine was negatively correlated with glycine while cystine and alanine were positively correlated with serine and proline. A second pool was characterized by strong positive correlations between leucine, valine, isoleucine, and threonine. These two groups were linked by a negative (hyperbolic) correlation between cystine and threonine. Preliminary data then gave evidence that the slopes of the linear regressions of Gly on Ser and Ala on Ser increased and those of Ile on Thr and Val on Leu decreased with increasing doses of B. thuringiensis israelensis delta-endotoxin. Functional relationships thus exhibited a high semiological value in metabolic stress studies.