MYTHIMNA. UNIPUNCTA )HAWORTH( پارازيتوييد انفرادي داخلي لارو شب پره تك نقطه اي برنج METEORUS GYRATOR THUNBERG )HYM., BRACONIDAE( بررسي هاي مرفولوژيك و بيولوژيك زنبور پارازيتوييد

Study of morphological and biological characteristics of parasitoid wasp, Meteorus gyrator Thunberg (Hymenoptera: Braconidae), a solitary endoparasitoid of the rice armyworm, Mythimna unipuncta (Haworth)

It is neecesary to identify potential of biocontrol agents for use against lepidopterous pests in fields and gardens. The solitary endoparasitoid Meteorus gyrator(Thunberg) attacks a range of macrolepidopterous larvae, including those of important crop pests and also the rice armyworm, Mythimna unipuncta (Haworth). Laboratory trails designed to investigate the biology and morphology of M. gyrator on larvae of the rice armyworm, M unipuncta shows that parasitoid have different stages including egg, first, second and third larval instars and pupae and adult. The egg and larval stages as solitary parasitoid are in the host larvae and in the last larval instar emerges from host larvae and change into pupae. This study revealed that the parasitoid is capable of parasitizing all larval stages of its host, third instars being parasitized most frequently. Each female parasitoid lives for up to 40 days (at 250C), ovipositing into an average of 70 hosts. Pre adult development is rapid (about 2 weeks), and sex ratio of offspring is 1:1. This parasitoid is capable to parasitize and destroy between 10% to 30% of M unipuncta larvae in critical months (August and September). The parasitoid can exist on different hosts in cereal crop, vegetables and woody plants in autumn and winter and therefore is capable to preserve its population and begin to parasitize Mythimna larvae in upcoming year and in the rice fields.