Tadashi NEMOTO, Yasumasa KUWAHARA*, Hiroshi NAKANISHI
National Institute of Bioscience and Human-Technology, Tsukuba, Ibaraki, 305
Japan
Pesticide Institute, Kyoto University, Kyolo, 606-01, Japan
Parasitic wasp Nementis canescens attacks larvae of Pysitid moths. Kairornone which release a series of oviposition behavior is known as 2-acylcyclohexane-1,3diones and their hydoroxylated form at 4-position in 6 membered ring. These non volatile compounds are acting as contact chemical.
To identify volatile kairomone, we obtai1ned steam distillate from rice bran, which was foodstuff for host larvae. Gas chromatography(GC, and Gas chromatography/Mas spectrometry analyses were carried out to find electoroantennogpaphy(EAG)-activity. A fraction from preparative GC contained peach-like sweet flavor and the structure was elucidated y-nonanoic lactone(nonane-4-olide) . Air puffs containing this compound released zigzag searching walk among resting parasitoids. This activation cue was compatible with vibration of insect cage.
The antennae of this parasitoid are whip-like and severely fragile, so we designed a new EAG chamber made of plastic plates and used with dental wax for fixing dissected antenna.
Electoro-antennogpapic study using y-nonanoic lactone together with related compounds was carried out and y-nonanoic lactose gave tern high response on parasitoid antenna.