Behavioral and antennal responses of Lobesia botrana (Lepidoptera: Tortricidae) to volatiles from the non-host plant Schinus molle L. (Anacardiaceae)

Diego Silva1, Tomislav Curkovic2, and Ricardo Ceballos1*
Lobesia botrana (Lepidoptera: Tortricidae),the grapevine moth, is one of the major pest on grapes. Current control is based on spraying insecticides and/or mating disruption technique, using female sex pheromone, affecting only adult male’s conduct. Behavioral active compounds as plants kairomones influence the interaction of phytophagous insects with plants, providing chemical cues to feed or lay eggs. Through electroantennography (EAG) and olfactory experiments, we investigated the role of volatiles of the non-host plant Schinus molle L. on behavior of L. botrana. Steam distilled essential oil (EO) from S. molle leaves was characterized by gas chromatography coupled to mass spectrometry (GC-MS). The most abundant compounds were limonene (17.61%), α-phellandrene (14.32%), β-caryophyllene (8.82%) and δ-cadinene (9.39%). Electrical responses of L. botrana at 1×102 µg mL-1 EO were not different from control for females (0.81 mV) and males (1.22 mV). At 1×103 and 1×104 µg mL-1 EO we found a significant increment for females to 1.28 and 1.57 mV, and 1.28 and 1.69 mV for males, respectively. In tube-Y olfactometer, at 1×102 µg mL-1 EO the choice did not differ from the control for females (P = 0.7630) and males (P = 0.4054). Females were attracted to odor source at 1×103 µg mL-1 (P = 0.0043) and at 1×104 µg mL-1 (P = 0.0011). Males were attracted to the dose of 1×103 µg mL-1 (P = 0.0278) and at 1×104 µg mL-1 (P = 0.0017). We found that non-host plant volatiles elicited electrophysiological and behavioral responses and that L. botrana can discriminate between doses.
Keywords: EAG, insect behavior, olfactometer, plant volatiles.
1Instituto de Investigaciones Agropecuarias, INIA Quilamapu, Av. Vicente Méndez 515, Chillán, Chile.
*Corresponding author (rceballos@inia.cl).
2Universidad de Chile, Facultad de Ciencias Agronómicas, Av. Santa Rosa 11315, Santiago, Chile.