An antagonist of the neurotransmitter tyramine inhibits the hyperactivating effect of eugenol in the blood-sucking bug, Triatoma infestans.

Eugenol is a botanical monoterpene found in the essential oils of several aromatic plants. It has shown to have insecticidal activity, modify insect behavior, and its site of action is most probably in the octopaminergic system. The aim of the present study was to explore whether tyramine receptors are involved in the hyperactivity produced by eugenol in Triatoma infestans, one of the main vectors of Chagas disease.

Botanical monoterpenes synergise the toxicity of azamethiphos in the vector of Chagas disease, Triatoma infestans (Hemiptera: Reduviidae).

Objective: To investigate what toxicological interactions occur when binary combinations of azamethiphos and botanical monoterpenes (eugenol, menthol or menthyl acetate) are applied to Triatoma infestans.

Methods: The toxicity of binary mixtures of azamethiphos and sublethal doses of a monoterpene (eugenol, menthol or menthyl acetate) was evaluated in nymphs of the first stage of T. infestans.

Eugenol-hyperactivated nymphs of Triatoma infestans become intoxicated faster than non-hyperactivated nymphs when exposed to a permethrin-treated surface.

Background: Eugenol is a botanical monoterpene that hyperactivates the blood-sucking bug Triatoma infestans, and permethrin is a pyrethroid with a strong triatomicide effect. In the present work, we tested the hypothesis that eugenol-hyperactivated nymphs of T. infestans pick up more insecticide, and then become intoxicated faster, than non-hyperactivated nymphs when exposed to a permethrin-treated surface.