Bioatividade do líquido da castanha do caju (LCC) e caracterização das sensilas antenais da praga Anacampsis phytomiella BUSCK, 1914 (Lepidoptera: Gelechiidae)

Abstract

Cashew productivity is compromised by the action of several insect pests, especially the cashew moth. Chemical control, although widely used, has limitations and risks. The need to develop more efficient and sustainable control methods drives the search for new alternatives, such as exploring the genetic resistance of plants. The presence of specific chemical compounds in cashew trees can act as a natural barrier that is unfavorable to the phytophagous insect. This study aims to: 1. Quantify the anacardic acids present in the LCC extract in maturis (young fruits) of different healthy genotypes and those infested by the chestnut moth, and evaluate the olfactory response of the pest to the extracts; 2. Analyze the morphology and types of antennal sensilla between males and females of A. phytomiella. The results indicate that: 1. The healthy genotypes PRO_155/2, PRO_130/1 and CCP_76, as well as the infested genotype PRO_115/2, presented similar anacardic acid profiles. However, the genotype PRO_143/7, both healthy and infested, presented similar levels of monoene and triene, while the infested PRO_130/1 presented the highest levels of these compounds. The infested genotype CCP_76 presented the highest levels of diene. The olfactory response of A. phytomiella to the LCCs of the infested and healthy genotypes did not differ from each other. However, the total response of the tested insects was higher for PRO 130/1, indicating that this oil may contain volatile compounds (VOCs) detected by these individuals. Nine types of sensilla were identified: trichode, basiconic, chaetic, coeloconic, styloconic, squamiform, auricilic, peg uniporous and Bohm's bristles. Trichode and basiconic sensilla are frequent in both sexes, while coeloconic and styloconic sensilla are the most abundant in females and uniporous sensilla are the least abundant among the sensory structures found in the antennae of both sexes. Thus, it is concluded that in the maturi phase, susceptible cashew genotypes tend to increase the concentrations of anacardic acids present in the LCC as a defense against the attack of A. phytomiella; The LCC of the total genotype PRO_130/1 (healthy and infested) can influence the behavior of A. phytomiella, and may have specific mixtures of compounds that guide the insect to the host plant. The antennae of the chestnut moth have several sensilla located along the entire length of the antenna.