Coupled gas chromatographic-electroantennographic responses of Xanthogaleruca luteola (Müller) (Coleoptera: Chrysomelidae) to volatile organic compounds from Eucalyptus globulus extract

Luis Reyes-García1*, Fabian Lizama1, Valeska Roldan1, Carmen Troncoso1, and Marcos Flores1
Xanthogaleruca luteola (Müller) is a monophagous pest species indigenous to Europe, known as elm leaf beetle. During the larval and adult stages, this insect damages elm leaves as it chews small holes in the leaves, causing, even, complete defoliation, leaving only the nervation. Although this species only uses Ulmus spp. as host plants to complete its development, some preliminary results have shown that is attracted to non-host plants such as Eucalyptus globulus Labill. In order to understand the role of volatile organic compounds emitted by E. globulus when the insect is attracted to this non-host plant, dichloromethane extracts of E. globulus were analyzed through gas chromatography-mass spectrometry, and main compounds were identified. Likewise, to evaluate the response of the antennae in X. luteola males and females to the compounds contained in the extract, a gas chromatographic-electroantennographic detection (GC-EAD) was conducted. Only females were observed to respond to α-pinene, eucalyptol, 4-terpineol, α-terpineol, α-terpineol acetate, α-gurjunene, alloaromadendrene, alloaromadendrene, viridiflorene, and globulol compounds. This study is the first step to identify substances mediating the host plant selection of X. luteola.
Keywords: Electroantennography, elm leaf beetle, insect behavior, olfactometry.
1Universidad Santo Tomás, Facultad de Ciencias, Departamento de Ciencias Básicas, Limonares 190, Viña del Mar, Chile.
*Corresponding author (luisreyesga@santotomas.cl).