Spatial Repellency Caused by Volatile Pyrethroids is Olfactory-Mediated in the German Cockroach Blattella germanica (Dictyoptera: Blattellidae

E. BONNE; P. GONZALEZ AUDINO; V. SFARA

NEOTROPICAL ENTOMOLOGY

ENTOMOLOGICAL SOC BRASIL

Lugar: BRASIL; Año: 2019

1519-566X

">RECTED PPyrethroids are synthetic insecticides that have a repellent action. Thiseffect has been associated with an increase in the locomotor activity,which causes the avoidance of the insecticide-treated area (excito-repel-lency). In this work, we studied with behavior and electrophysiologicalrecordings the occurrence of olfactory-mediated repellency caused bypyrethroids of different volatility in the German cockroach Blattellagermanica (Linnaeus, 1767). Male cockroaches were spatially repelledwhen they were exposed to D-allethrin vapors and vapothrin vapors in adose-dependent manner. No repellency was observed when insects wereexposed to permethrin, a non-volatile pyrethroid. To confirm the role ofolfaction in this phenomenon, we measured the electrical activity of thecockroaches? antennae in response to these insecticides. There was asignificant increase in the electrical activity in response to D-allethrin andvapothrin, but no increase was observed in insects exposed to permethrin.Locomotor activity of cockroaches exposed to pyrethroids was measuredin order to discard excito-repellency. No changes in locomotor activitywere observed for any of the insecticides. Finally, we found that volatilepyrethroids in the vapor phase cause spatial repellency in cockroaches,being the first report of an olfactory-mediated repellency phenomenoncaused by pyrethroids in cockroaches