RESUMO
ABSTRACT Neoleucinodes elegantalis is an important tomato pest in Brazil, occurring throughout the country and resulting in economic losses in agriculture. In several species, biogeographic studies in Brazil indicate the structuring of populations, following the refuge model, with a split between the populations of the northeast and the southeast regions of Brazil. The objective of this work was to analyze the phylogeography of N. elegantalis in Brazil, understanding its population structure and the demographic patterns. Larvae were collected from eight locations throughout Brazil, and the mitochondrial cytochrome c oxidase subunit 1 gene was analyzed. A total of 628 bp in 51 individuals were obtained, showing 12 haplotypes with a haplotype diversity of 0.836. Spatial analysis of molecular variance (SAMOVA) and cluster analysis showed two populations, indicating population structuring between individuals from the northeast (population 1) and southeast (population 2) regions of Brazil. Phylogenetic analysis indicated that the clades corresponding to the groups defined by SAMOVA have a divergence time of 0.2–0.5 million years, suggesting isolation during climatic events and a separation of the two populations coinciding with the predicted refuges to the Atlantic forest.
RESUMO
Foram avaliados os quatro componentes sintéticos identificados no feromônio sexual da broca-pequena-do-tomate, Neoleucinodes elegantalis Guenée (BPT): (E)-11-hexadecenol (E11-16:OH), (Z)-11-hexadecenol (Z11-16:OH), (E)-11-hexadecenal (E11-16:Al) e (E)-11-Acetato de hexadecenila (E11-16:OAc). Testes de campo foram realizados com armadilhas objetivando identificar o composto mais eficaz na captura de machos do inseto e determinar o efeito de concentrações do isômero Z11-16:OH, em mistura com o componente mais eficaz na captura de machos. Em laboratório, foram realizados testes eletrofisiológicos com eletroantenógrafo para monitorar as respostas da antena de machos de N. elegantalis a diferentes concentrações dos componentes. E11-16:OH, na concentração de 100 æg foi o mais eficaz entre os componentes testados do feromônio sexual da BPT. A adição de seu isômero, Z11-16:OH, reduziu a captura de insetos. Obteve-se resposta fisiológica (potencial de ação) a todos os componentes testados. Para E11-16:OH, a intensidade de despolarização da antena aumentou em relação direta com sua concentração, no entanto, para os demais componentes, os quimioreceptores foram sensíveis somente nas concentrações mais altas.
Four synthetic components of the sexual pheromone identified from the small tomato borer Neoleucinodes elegantalis Guenée (BPT) were evaluated: (E)-11-hexadecenol (E11-16:OH), (Z)-11-hexadecenol (Z11-16:OH), (E)-11-hexadecenal (E11-16:Al) and (E)-11-hexadecenyl acetate (E11-16:OAc). Field tests were carried out with traps aiming at identifying the most effective component in the capture of N. elegantalis males, and determining the effect of different concentrations of the isomeric Z11-16:OH, in a mixture with the most effective component, in the capture of the males. In laboratory, electrophysiological tests were carried out with an electroantennograph to monitor the response of the antenna of N. elegantalis males to logarithmic concentrations of the four identified components. E11-16:OH, at the concentration of 100 æg, was the most effective among the tested components of the sexual pheromone of BPT. The isomer of this component, Z11-16:OH, was added and reduced insect capture. Physiological responses to all tested components were registered. E11-16:OH promoted depolarization of the antenna in straight relation with its concentration, while for the others components, the chemoreceptors have responded only to the higher concentrations.