UNIDEF   23986
UNIDAD DE INVESTIGACION Y DESARROLLO ESTRATEGICO PARA LA DEFENSA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Olfactory-mediated repellency is observed in Blattella germanica exposed to pyrethroids
Autor/es:
GONZALEZ AUDINO PAOLA; VALERIA SFARA; EMILIANO BONÉ
Lugar:
Foz do Iguazu
Reunión:
Congreso; International Chemical Ecology Conference; 2016
Institución organizadora:
Universidad Federal do Parana
Resumen:
Pyrethroids are synthetic insecticides usedworldwide. In addition to their insecticidal effect, they have been reported asrepellents. This repellency is associated with an increase in the locomotoractivity of insects caused by the interaction of the pyrethroid with central a nervoussystem target. As a consequence, insects avoid the source of the pyrethroid,with a kinetic response. This phenomenon is called excito-repellency. On the other hand, an insect repellent isdefined as a chemical that produces oriented movements against the source of repellency.In this case, the repellent interacts with olfactory receptors. In this work westudied whether the pyretroid  d-allethrin elicits an oriented repellencyresponse mediated by olfaction in Blattellagermanica. Behavioral experiments were conducted on acircular arena with one half of its floor treated with d-allethrin. Threeexperimental series were performed: insects exposed to a film of d-allethrin;insects exposed to d-allethrin vapors at room temperature; insects exposed tod-allethrin vapors at 40 °C. One male of B. germanica was placed in the center of the arena and its spatialdistribution was determined. Additionally, the electrical activity of thecockroaches? antennae was recorded using electroantennography, to ensure thatthe insecticide was detected by olfactory receptors.In the behavioral experiments repellency wasobserved in a dose-dependent manner. When insects were exposed only tod-allethrin vapors at room temperature, repellency was not observed, unless  the vapour fraction of the insecticide wasincreased by heating. In the electroantenographic assays a significantelectrical response was recorded when the antennae were exposed to aconcentration of d-allethrin that produced repellency in the behavioral bioassays.This indicates that the insecticide is detected by olfactory sensilla, andrepellency is the behavioral associated response to that stimulus. We concludethat d-allethrin produces olfactory-dependent repellency in B. germanica.