IDENTIFICATION OF CUTICULAR COMPOUNDS OF THE BROWN CATERPILLAR WINGS, Thyrinteina arnobia Stoll (LEPIDOPTERA: GEOMETRIDAE)

Abstract

The genus Eucalyptus (Myrtaceae), originating in Australia, occupies a prominent place in the economic sector in Brazil, where the eucalyptus crop is the emblem of the brazilian forest business. With the expansion of eucalyptus, there is also the emergence of native or exotic pest insects, responsible for causing significant yield losses. Among these insects, the eucalyptus brown caterpillar Thyrinteina arnobia Stoll (Lepidoptera: Geometridae), which naturally attacked native species of the Myrtaceae family in Brazil, is cited as the most important defoliating lepidoptera for eucalyptus in the country. The objective of this research was to study, isolate and structurally identify cuticular compounds of T. arnobia collected from eucalyptus stands in the areas of Alagoas, enabling the implementation of an Integrated Forest Pest Management (IPM Forests) program. The research was conducted at the Agricultural and Forest Entomology Laboratory (LEAF) of the Center for Agricultural Sciences (CECA) and Natural Resources Research Laboratory (LPqRN) of the Institute of Chemistry and Biotechnology (IQB) at the Federal University of Alagoas (UFAL). The extraction of cuticular compounds from the brown caterpillar was directed to 24-48h old female and male wings. The fore and hind-wings were removed and fully immersed in hexane solvent for 20 min. The selected extracts were filtered and analyzed by gas chromatography with flame ionization detector (GC-FID), where the indicators were compared with the C13 and C7-C30 alkane standards. With this comparison, it was possible to calculate the respective Kovats Indexes (KIs) and to identify, through Pherobase, the possible compounds of the fore and hind-wings parts of adults (males and females) of T. arnobia.