2 ‘Mass production of NPV ’’ DEPARTMENT OF ENTOMOLOGY KRISHI MAHA VIDYALAYA, TIKAMGARH, (M. P.) PRESENTED BY : DEENDAYAL DANGI Roll No. 5758
Nuclear Polyhedrosis Virus (NPV): Important features - Occluded (rod shaped) singly or in groups in polyhedral inclusion bodies. Site of multiplication is cell nucleus of epidermis, fat body,blood cells and trechea . Wipfel Krankeit or tree top disease: Diseased larvae not able to feed ,move to the top of the tree or plant and hang inverterdly and die. eg. NPV of Spodoptera, Helicoverpa . Mode of entry : The virus should be ingested to produce the disease.Due to alkaline gut juice, the virions are liberated from the polydedral coat which attack nuclel of cells of tissues, fat body tracheal matrix, haemocytes,sarcolemma of muscles, neurilemma and nerve cell of anglion and brain.
Mass prodution of NPV of Spodoptera litura: S. liutra can be mass cultured using the natural diet, castor leaves under laboratory condition in plastic buckets.The steps involved in the prodution of NPV are: nbv Pre starve 4 th instar larva –over night Prepare virus suspension containing 10 8 POB/ml in water containing 0.1% teepol. Dip clean castor leaves in virus suspension and shade dry Allow the caterpillar to feed for two days and subsequently on untreated leaves Collect the diseased larvae in distilled water
Allow to putrefy 5 days Polydedra settles at bottom as white layer Sediment contain POB Suspend in distilled water Centrifuge for 1 min at 500 RPM Supernatant containing POB s
Centrifuge at 2500 RPM for 15 min Collect pellet (POB’s) Resuspend in distilled water Repeatdifferential centrifugation Pure POB’s The dose of virus is expressed as larval equivalent(LE ).