Reduction of Triatoma infestans (Hemiptera:Reduviidae) experimental populations exposed to feeding inhibitors.

We found that feeding behavior of Triatoma infestans (Klug) 5th-instar nymphs was blocked by topical application of the cis-isomers of methyl esters of N-substituted maleamic acids, synthesized in our laboratory. The antifeeding effect of these compounds was determined by exposing 5th-instar nymphs to impregnated filter papers. The greatest antifeeding effect was observed for the shortest alkyl chain of cis-N-substituted methyl maleamate (EC50: 2.47 micrograms/cm2 when the substituent was ethyl and 65.1 micrograms/cm2 when it was octil). The continuous exposure of a T. infestans population to ethyl, buthyl, heptil, or octil maleamates at an initial concentration of 0.1 mg/cm2 produced significant (P < 0.05) decrease in the development of the exposed populations ranging from 220 to 400 d for the different maleamates assayed. These results suggest the antifeeding maleamates as a specific alternative method of T. infestans control.