BEHAVIORAL RESPONSES OF MACROCENTRUS LINEARIS TO PLANT VOLATILES

QIU HONG-GUI HE LI-FEN SHEN PAK-QUAN QIU ZHONG-LIANG(Shanghai Institute of Entomology, Academia Sinica, Shanghai)

Macrocentrus linearis--Ostrinia furnacalis--plant volatile--olfacto-meter

The behavioral responses of Microcentrus linearis, a parasitoid of the Asian corn borer Ostrinia furnacalis (Guenee), to plant volatiles were , studied with an .olf'actometer and observed with Petri dishes containing vegetable fragments or filter paper soaked with crude extracts from plants. The results showed that the female 'wasps were attracted by the volatiles. of the host plants of the insect host of the parasitoid such as corn and cptton, but they would not probe-the substratum with ovipositors. However, the host'plants damaged by the corn borer larvae, even in the absence,of the latter, could induce ovipositor probing, of the female wasps. Volatiles from non-host plants of its insect host such as soybean and Chenopodium album were neither attractive nor repellent to the female wasps. When undamaged and damaged host plants of its. insect host were presented to the female wasps for their choice they preferred the latter. When the odors of the non-host plants and host plants of their insect host from different directions were presented to the female wasps, they were attracted by the odor of the host plants. The host plant volatile can be extracted with ether, and the filter paper soaked with the extract; can elicit antennal drumming and searching behavior of the female wasps.