【摘要】 <正> 草原毛虫属鳞翅目(Lepidoptera)毒蛾科(Lymantriidae)的一种主要牧草害虫;该虫与草原鼠害并称为我国草原的两大灾害。草原毛虫分布广,仅川西北草原受害的草场面积已达1600万亩以上;为害时间长,通常每年四月越冬幼虫开始出现活动为害,至九月化蛹,为害期长达半年之久,整个放牧期间持续为害。草原毛虫危害的草类,正是牲畜的主要牧草。该虫多集中于草料丰茂地带,虫口密度多达170——530头/米~2。川西北草原每年因该虫的危害损失天然牧草,相当于100万只羊单位的全年饲料,价值数千万元。更多还原

【Abstract】 From 1982 to 1983, Some dead larvae of Pasture Tussock Moth were collected from a Pasture in The north-west of Sichuan province, China. A Pathogenic virus was isolated from The insect. Investigation and identification of that virus were carried out in The following aspects:1. Under the scanning electron microscope, the plane image of the viral Polyhedron appears to be triangular, Pentagonal, hexagonal, Polygonal, hemicircular or circular; but its stereoscopical image appears to be irregularly polyhedronal or spherical. Stratified accumulations, papillae, beaks, furrows and bud-eyes are found on the surface. The size of the polyhedron varies from 0.266 to 2.793, w ith 1.43 as its average.Ultra-thin sections of The polyhedron were examined under a transmitting microscope, it was revealed that a polyhedron contains a few to many rod-shaped viria and each virion is enclosed in an outer membrane, which is of unicapsid morphotype. Cracks and holes in the polyhedrin could be seen. The crystalline pattern of the polyhedrin is either square or linear-shaped.Free Viria obtained after treatment of the polyhedra are rod-shaped and 93x296nm in size.The nucleic acid of the virus was identified to be of the DAN type.Histological sections showed that the polyhedra first appear in the cell nuclei.According to the Classification and Nomenclature of Virus proposed by ICTV in 1975, the virus of Gynaephora ruoergensis Chou et Yin belongs to subgroup A of the genus Baculovirus, i.e. nuclear polyhedrosis virus, so we denominate this new virus as Gynaephora ruoergensis Chou et Yin nuclear polyhedrosis virus which may be abbreviated as GrNPV.2. Analyses of amino acid content of polyhedrin showed that the polyhedrin is rich in lucine plus isolucine, aspratic acid and glutamic acid. This is a common charactereste for polyhedra of all insect viruses both NpB and CPB.3. The results of preliminary bioassay show that the larvae are suseptible to GrNPV, and the mortality rate of 6-instar larvae at 1 x 107 NpB/ml may reach 90% within a period of 12 days. The application of GrNPV in controlling Pasturetussock Moth (Gynaephora ruoergensis Chou et Yin) ----- a major pest in thepastures of our country seems to be feasible.更多还原