Mass%20Multiplication%20of%20Microbial%20Pesticide - PowerPoint PPT Presentation

About This Presentation
Title:

Mass%20Multiplication%20of%20Microbial%20Pesticide

Description:

Mass Multiplication of Microbial Pesticide Production of Helicoverpa armigera Nucleopolyhedrovirus (HaNPV) * * Gram pod borer Helicoverpa armigera In India gram pod ... – PowerPoint PPT presentation

Number of Views:372
Avg rating:3.0/5.0
Slides: 12
Provided by: Dr23719
Category:

less

Transcript and Presenter's Notes

Title: Mass%20Multiplication%20of%20Microbial%20Pesticide


1
Mass Multiplication of Microbial Pesticide
Production of Helicoverpa armigera
Nucleopolyhedrovirus (HaNPV)
2
Gram pod borer Helicoverpa armigera
  • In India gram pod borer Helicoverpa armigera is
    the most serious pest of crops in India.
  • It is a polyphagous, major pest of cotton, legume
    crops like gram, chickpea, pigeon pea, pea,
    maize, sunflower, tomato and many other
    agriculturally important crops.
  • Female of this insect lay 200-400 eggs on
    inflorescence, leaves and pods.
  • The eggs are round bright greenish yellow in
    colour.
  • Damage is caused by larvae of this pest

3
Background
  • The virus Helicoverpa armigera nucleopolyhedrosisv
    irus (HaNPV) that naturally infects H. armigera,
    has been isolated and is employed as a 'viral
    insecticide' against this pest.
  • Aqueous suspension of HaNPV extracted from
    diseased larvae is used in a spray on crops.
  • It is highly specific self perpetuating/
    recyclable.
  • The HaNPV has been found to be safe to mammals,
    non-target insect and environment.
  • It is an important microbial control option of
    IPM available for H. armigera management.

4
Symptoms of HaNPV Infection
  • The Helicoverpa armigera larvae infected with NPV
    become-pinkish /pale in colour.
  • Swell slightly and then become limp and flaccid.
  • In field prior to death, larvae infected with NPV
    climb up the plant and hang by their prolegs
    upside down.
  • Tissues get disintegrated and liquefied.

5
Production of HaNPV
  • Being obligate, virus has to be produced only in
    live insects.
  • Thus, for the production of HaNPV, either rear H.
    armigera on large scale or collect the larvae
    from field and use them for HaNPV production.
  • Collect the 250 larvae (6-7 day old) of H.
    armigera from field.

6
  • Larvae are singly placed in plastic tubes
    containing food contaminated with NPV.
  • After 7-8 days collect larvae showing the
    symptoms of NPV infection before they liquefied,
    in air tight container.
  • Keep this container for 8-10 days to decompose
    the larvae, so that polyhedra released from
    infected tissue.

7
Cont
  • Homogenize the decomposed suspension of diseased
    larvae using a homogenizer.
  • Dilute the homogenized content with small amount
    of water and filter through two layers of muslin
    cloth.
  • Little water is sprinkled 2-3 times over the
    remnants to extract residual polyhedra.
  • For crude preparation the filtrate is diluted
    with water to make solution of 250 ml.
  • This is known as 250 LE (LE-larval equivalent)
    HaNPV
  • HaNPV in stoppered bottle, and store in cool and
  • dry place.

8
  • 250 LE (LE-larval equivalent) HaNPV.
  • The effectiveness of the viral insecticide is
    critically dependent on the concentration of POB,
    which is expressed as larval equivalent (LE).
  • A standard 1 LE stock preparation consists of 6
    109 POBs/ml.

9
Use of HaNPV in Field
  • The field application rate of 250-500 LE/ha of
    HaNPV has been recommended for the control of H.
    armigera by different workers on various crops.
  • The virus is highly specific to target insect. So
    it has no deleterious effect on non-target
    organisms and environment

10
Summary
  • Mass production of HaNPV insecticide is simple
    and widely produced even at the village level.
    Healthy H. armigera larvae reared in the
    laboratory or collected from the fields are fed
    with a low dose of HaNPV and the virus produced
    in the insect is harvested.
  • Its concentration is estimated by counting
    polyocclusion bodies (POBs), which are aggregates
    of HaNPV particles encased by the viral
    polyhedrin protein.
  • The effectiveness of the viral insecticide is
    critically dependent on the concentration of POB,
    which is expressed as larval equivalent (LE).
  • A standard 1 LE stock preparation should consists
    of 6 109 POBs/ml.

11
References
  • http//www.fao.org/docs/eims/upload/agrotech/2011/
    HaNPVmanual-pt1.pdf
  • http//www.kvk.pravara.com/horti/dbtbiocontrol.htm
  • http//www.icrisat.org/what-we-do/satrends
    /may2007.htm
Write a Comment
User Comments (0)
About PowerShow.com