Comportamento sexual de Atheloca bondari Heinrich, 1956 (Lepidoptera: Pyralidae): descrição e mediação por feromônios

Abstract

The coconut tree, Cocus nucifera, is grown in all regions of Brazil, predominantly in the northeast, and is a socioeconomically important species. In addition to be a major source of economic income, C. nucifera is used as a resource by several insects, which affects its growth and causes economic losses to producers. Among these insects, the coconut moth, Atheloca bondari Heinrich, 1956 (Lepidoptera: Pyralidae) presents a great importance in the coconut culture, because its control is hampered by the endophytic habit of its caterpillars. The present work aimed to extract and identify pheromonal compounds emitted by coconut moth females. DNA extractions from the coconut moth were performed to confirm the identity of this species, and scanning electron microscopy (SEM) analysis of the adults antennae was conducted to investigate chemical communication in this species. To study the mating behaviour of the coconut moth adults, behavioural bioassays of courtship and copula in arena were accomplished. Female genitalia extracts and whole-body extracts of males and females were obtained using hexane as the solvent. The extracts were analyzed by gas chromatography coupled to mass spectrometry (GC-MS) and gás chromatography coupled to flame ionization detector (GC-FID). The responses of the adult antennae to the extracts and synthetic compounds was tested by means electroantennography (EAG) and gas chromatography coupled to electroantennography detector (GC-EAD). Through the DNA extraction, amplification and sequencing a final sequence with 678 bp was obtained. The SEM analyses resulted in the identification of 6 types of sensilla: Böhm's bristles, trichoidea, chaetica, coeloconica, auricillica, chaetica, and styloconica. The behaviour bioassays revealed courtship and copula patterns performed by males and females of the coconut moth. Through the analysis of the extracts, it was possible to identify 23 compounds present in the female genitalia and 39 compounds present in the male and female cuticular profile. The electroantennographic analyses revealed that male antennae are activated by the cuticular and genital extracts of female and by 3 compounds identified as pheromone to Pyralidae species. Based on the results of this research it is possible to conclude that mating in A. bondari is mediated by pheromonal compounds.