Toxicity, repellency and flushing out in Triatoma infestans (Hemiptera: Reduviidae) exposed to the repellents DEET and IR3535

REYNOSO MMN; SECCACINI E; CALCAGNO JA; ZERBA EN; ALZOGARAY RA

Peer J

Peer J

Año: 2017 vol. p. 1 - 14

2167-8359

DEET and IR3535 are insect repellents present worldwide in commercial products, which efficacy has been mainly evaluated in mosquitoes. This study compares the toxicological effects and the behavioral responses induced by both repellents on the blood-sucking bug Triatoma infestans Klug (Hemiptera: Reduviidae), one of the main vectors of Chagas disease. When applied topically, the Median Lethal Dose (72 h) for DEET was 220.8 µg/insect. Using IR3535, topical application of 500 µg/insect killed no nymphs. The minimum concentration that produced repellency was the same for both compounds: 1,15 µg/square cm. The effect of a mixture DEET:IR3535 1:1 was similar to that of their pure components. Flushing out was assessed in a chamber with a shelter containing groups of ten nymphs. The repellents were aerosolized on the shelter and the number of insects leaving it was recorded for 60 min. During that time, 0.006 g/cubic m of the positive control tetramethrin flushed out 76.7% of the nymphs, while 1.76 g/cubic m of DEET or IR3535 flushed out 30 and 0%, respectively. The concentrations required for both compounds to produce toxicity or flushing out are too high to have any practical applications. However, they showed a promisory repellency. Additional research should be done to evaluate their possible use for personal protection against T. infestans bites.