Interações e ecologia química de Costalimaita ferruginea (Fabricius, 1801) (Coleoptera: Chrysomelidae) em clones de Eucalyptus urograndis (Myrtaceae)

Abstract

Eucalyptus cultivation was introduced in Alagoas through the expansion of clonal forest stands of Eucalyptus urograndis, replacing degraded areas and / or previously cultivated with sugarcane. The expansion and monoculture of E. urograndis, in extensive and contiguous areas, favor the occurrence of insect population outbreaks, such as the defoliator beetle, Costalimaita ferruginea (Fabricius, 1801) (Coleoptera: Chrysomelidae). Thus, the objective of this study was to analyze the interactions of C. ferruginea and E. urograndis clones (VE 41, I1 44, TP 361, VCC 865), through the evaluation of leaf consumption in laboratory; the elaboration of a visual diagrammatic scale for determination of the injury levels on the clones; and the verification of spatial, vertical and temporal of distribution patterns C. ferruginea injuries in an experimental forest stands on the Center of Agricultural Sciences of the Federal University of Alagoas (CECA/UFAL). In addition, the present study aimed to study the ecology of C. ferruginea in E. urograndis through the sampling of volatile compounds emitted by males and females, in the presence and absence of food, by headspace techniques. The results obtained in laboratory, indicate a higher leaf consumption of C. ferruginea on the clone I1 44 when compared to the clone VCC 865. A visual diagrammatic scale of injury notes of C. ferruginea in E. urograndis clones was determined with levels of injury varying from 1 to 4. Spatially, the injuries of C. ferruginea were mostly settled on the edge of the plot in relation to its interior. Vertically, the injuries showed a general pattern of distribution in the apical and medial region, varying among the clones. After 12 months, a low intensity of C. ferruginea mean injury was observed for all the E. urograndis clones. For chemical ecology, a total of 24 volatile compounds were identified. Among them, the compound Heptadecane was specific for the samples of C. ferruginea females. Tetradecene and (Z)-9- Octadecenoic acid, were specific for male samples. 2-Nonenal, trans Geraniol, α-Pinene and Tridecene, were specific for female and male samples in the absence of food. The compounds β-Ocimene, Linalool, (E,E)-2,8-Dimethyl-1,7dioxaspiro[5.5]undecane, α-Copaene and Octadecane were obtained in samples of males and females in the presence of food. The compounds trans-Caryophyllene and Eucaliptol were found in all analyzed samples. The results obtained are pioneers for the interaction of C. ferruginea and E. urograndis in the State of Alagoas and present basic information for the development of Forest Integrated Pest Management.