Ocorrência espontânea de inimigos naturais de Thyrinteina arnobia (Stoll, 1782) (LEPIDOPTERA: GEOMETRIDAE) em Eucalyptus spp. no estado de Alagoas e Ecologia química do endoparasitoide Palmistichus elaeisis Delvare & LaSalle (HYMENOPTERA: EULOPHIDAE)

Abstract

Among the pest insects associated with eucalyptus culture, the brown eucalyptus caterpillar, Thyrinteina arnobia (Stoll, 1782) (Lepidoptera: Geometridae), derived from native myrtaceous trees, such as guava (Psidium guajava L.), is considered the main defoliating species of the genus Eucalyptus in the country. In this sense, different methods that fit the premises of the Integrated Management of Forest Pests (IPM- Forest) have been the focus of research, including the use of biological control, through the conservation or multiplication and release of natural enemies. The gregarious endoparasitoid Palmistichus elaeisis Delvare & La Salle, 1993 (Hymenoptera: Eulophidae) is considered a promising agent in the control of defoliating lepidoptera, having generalist habits. For complete elucidation of the interactions that permeate the use of parasitoids in biological control programs, the understanding of the host search process is fundamental. In addition, it is through the olfactory sensory neurons located in the sensilla, present in the antennae of insects, that the parasitoid is able to locate its host. In view of the above, the objective of this study was to carry out survey studies of natural enemies of spontaneous occurrence of T. arnobia in forest stands of Eucalyptus spp., in addition to the evaluation of the chemical ecology in the use of the endoparasitoid P. elaeisis, and to study antennal sensilla in males and females of Pelaeis is, using scanning electron microscopyaiming (S.E.M) at directing the bases for the planning and implementation of the conservative and augmentative biological control of T. arnobia in the state of Alagoas. It was possible to register the spontaneous occurrence of the natural enemies, Winthemia sp. (Diptera: Tachinidae), Charops sp. (Hymenoptera: Ichneumonidae, Campopleiginae), Glyptapanteles sp. (Hymenoptera: Braconidae) and the predator Podisus sp. (Hemiptera: Pentatomidae) associated with T. arnobia in Eucalyptus sp. in the state of Alagoas. Compounds found in pupae of T. arnobia, indicated as 4-Hexen-1-ol, acetate; 2,3,5,6-Tetramethylpyrazine; 2-Nonanone and 1-Undecene present bioactivity in processes of attraction of the parasitoid P. elaisis. The antennae of females and males of P.elaeisis are characterized by the presence of three subtypes of trichoid sensilla, two subtypes of basiconic sensilla and placoid sensilla. Only males possess styloconic sensillae. The results obtained contribute to the consolidation of the Integrated Management of Forest Pests (IPM-Forest).