Effects of citronella grass extract on the oviposition behavior of carambola fruit fly (Bactrocera carambolae) in mango.
Muryati, Trisyono Y. A., Witjaksono, Wahyono
Author Affiliation: Indonesian Agency for Agriculture Research and Development, Indonesian Tropical Fruit Research Institute, Jl. Solok-Aripan, Solok, West Sumatra, Indonesia.
Journal of Agricultural and Biological Science 7 : 672-679
Abstract : Carambola fruit fly (Bactrocera carambolae) causes economic losses because the female deposit her eggs in fruits and the larvae bore into the fruits. The availability of non-preferred and safe substance in deterring the females to lays eggs will provide an effective tool to protect the fruits. This research examined three types of citronella grass extracts in regard with their effects on disturbing the oviposition behaviour. Water, methanol, and n-hexane citronella grass extracts were applied to fruits and the fruits were then exposed to gravid females. Olfactometry tests were carried out to investigate the mechanisms by which extracts modify B. carambolae oviposition. The methanol extract deterred the females for oviposition with OAI=-0.83, whereas the water extract and n-hexane extract had no effect on oviposition with OAI ranged -0.02 to 0.29 and -0.02 to -0.38, respectively. Furthermore, the olfactory test showed that the methanol extract had no effect on repellency. Therefore, the mechanism of reducing the oviposition was most likely through gustatory rather than olfactory processes. The major compounds in the methanol extract were silane, [[(3.beta)-lanosta-8, 24-dien-3-yl] oxy] trimethyl and elemol. The methanol extract of citronella grass has the potency to be used as a tool to protect mango from B. carambolae oviposition.