The octopamine receptor is a possible target for eugenol-induced hyperactivity in the blood-sucking bug Triatoma infestans (Hemiptera: Reduviidae)

REYNOSO MMN; LUCIA A; ZERBA EN; ALZOGARAY RA

JOURNAL OF ECONOMIC ENTOMOLOGY

ENTOMOLOGICAL SOC AMER

Lugar: Lanham; Año: 2020 vol. 57 p. 627 - 630

0022-0493

Eugenol is a major component of the essential oils in cloves and other aromatic plants. In insects, it produces toxic effects and repellency, and there is evidence that its site of action is the octopamine receptor. The objective of the present study was to explore whether the octopamine receptor is involved in the hyperactivity produced by eugenol in the blood-sucking bug Triatoma infestans (Klug). For testing this, we used phentolamine, an antagonist of the octopamine receptor. This insect is the main vector of Chagas disease in Latin America. Four treatments were topically applied on third instar nymphs: (a) octopamine, (b) eugenol, (c) phentolamine hydrochloride (pretreatment) followed by octopamine, and (d) phentolamine hydrochloride (pretreatment) followed by eugenol. Both octopamine and eugenol hyperactivated the nymphs. However, pretreatment with phentolamine hydrochloride inhibited the hyperactivating effect of both eugenol and octopamine. These results are in agreement with previous works on Drosophila melanogaster (Meigen) and the American cockroach. They suggest that the octopamine receptor is a possible site of action for eugenol.