Role of Plant Volatile to Diaphorina citri on Feeding and Oviposition Behaviour

Abstract

Citrus production in Indonesia and in the world is suffered from disease of citrus vein phloem degeneration (CVPD. It was vectored by psylids (Diaphorina citri). The psylids used citrus plant volatiles as cues for finding their host plants for feeding and laying eggs. Extract of guava leaves was a prospective control material for declaining population of psyllid. Investigation by research was conducted to determine the effect of CVPD symptomatic citrus plants in attracting psylids gravid female for staying and laying eggs, and also to determine the repellency ability of guava shoots to adult psyllids. Citrus buds of healthy plants and CVPD symptomatic plants were exposed to ten gravid female and the number of psylids stay and the number of eggs per bud was recorded. Y-tube olfactometer was used to determine repellent effect of upper shoot, middle shoot, and bottom shoot of guava leave to ten adult psyllids. The result shows that CVPD symptomatic plants was more attractive for laying eggs, eventhough the number of eggs was higher on healthy plants. Repellence effect to psyllids adult was identified in guava leave extracts. The increase of leaf age would decrease the effect. It was suggested that repellent properties was highest youngest leaf or upper shoots of guava.