关键词: 稻螟赤眼蜂, 赤眼卵蜂, 互利素, 寄生蜂, 水稻

Abstract: Bioassays of the hexane extracts of nine varieties viz., Pusa Sugandh-2, Pusa Basmati-1, Pusa-2511, Pusa Basmati-370, Pusa-1077, Karnal Local, PRR-78, Jaya, Pusa-1238 and one culture of rice, Culture No.34 in vegetative and flowering phase were carried out in Petri dish, to observe their synomonal effect on mean parasitoid activity index (PAI) and mean percent parasitism by Trichogramma japonicum, Ashmead and Trichogramma chilonis (Ishii). The hexane extracts of different rice varieties were subjected to gas liquid chromatography to determine the saturated hydrocarbons. Among these, leaf extracts from variety Pusa Sugandh-2 elicited maximum response in vegetative phase for both the parasitoids by way of mean percent parasitism. Whereas in flowering phase variety Pusa Basmati-1 elicited maximum mean percent parasitism. Gas liquid chromatography of the leaf extracts from vegetative phase revealed that Pusa Sugandh-2 had two favorable hydrocarbons pentacosane (C25) and nonacosane (C29). Gas liquid chromatography of leaf extract from flowering stage also revealed that Pusa Basmati-1 had three favorable hydrocarbons viz., pentacosane (C25), hexacosane (C26) and nonacosane (C29) which could be ascribed to the highest response elicited by these varieties.

Key words: Trichogramma japonicum, Trichogramma chilonis, synomone, parasitoid, rice