jnkvv college of agriculture tikamgarh

2. 2
‘Mass production of NPV’’
DEPARTMENT OF ENTOMOLOGY
KRISHI MAHA VIDYALAYA, TIKAMGARH, (M. P.)
PRESENTED BY : DEENDAYAL DANGI Roll No. 5758

3.  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.

4.  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 4th instar larva –over night
 Prepare virus suspension containing 108 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

5. 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

6.  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).