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

• Published in: PeerJ (San Francisco, CA) CA), 2017-05, Vol.5, p.e3292-e3292, Article e3292
• Main Authors: Reynoso, Mercedes M N, Seccacini, Emilia A, Calcagno, Javier A, Zerba, Eduardo N, Alzogaray, Raúl A
• Format: Article
• Language: English
• Subjects: Analysis; Bioassays; Blood-sucking bugs; Camcorders; Cameras; Chagas disease; Culicidae; DEET; Diethyltoluamide; Disease; Entomology; Ethyl 3-[acetyl(butyl)amino]propanoate; Handbooks; Hemiptera; Insect bites; Insect control; Insect repellents; Insects; Laboratories; Lethal dose; Locomotor activity; Methods; Mosquitoes; Oils & fats; Recording equipment; Reduviidae; Repellency; Repellents; Shelters; Tetramethrin; Topical application; Toxicity; Toxicology; Triatoma infestans; Triatominae; Tropical diseases; Trypanosoma cruzi; Vectors
• ISSN: 2167-8359; 2167-8359
• DOI: 10.7717/peerj.3292

DEET and IR3535 are insect repellents present worldwide in commercial products; their 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 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/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/m of the positive control tetramethrin flushed out 76.7% of the nymphs, while 1.76 g/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 promising repellency. Additional research should be done to evaluate their possible use for personal protection against bites.