Viral Biopesticides - The inside story

1. VIRAL
BIOPESTICIDES

2. Viruses as Biopesticides
Vgydgwuy
Lepidoptera( 83%)
Hymenoptera (10%)
Diptera ( 4%)

3. Classification
• Baculoviruses
Nuclear Polyhedrosis Granulosis Virus
Virus
• Nucleic acid-single molecule of circular super
coiled DNA
• Virion structurally complex with 10 -25
polypeptides 4-11 associated with nucleocapsid
• Replication in host cell nuclei
• Cytoplasm Polyhedrosis
Virus

4. Nuclear Polyhedrosis Virus
• 41% of arthropod viruses develop in host cell
nuclei, virions occluded singly/groups in
polyhedral inclusion bodies.
• Rod shaped, double stranded; POBs 0.2-15µm in
diameter
• Highly host specific
• Enters through injection of plant material into
insect gut through mouth &cuticle
• Symptoms are:
- Discoloration (brown and yellow)
-Stress
-Decomposition (liquification)
-Lethargy
-Infected larvae hang invertedly from twigs
- host will become visibly swollen with fluid
containing the virus and will eventually die
turning black with decay

5. Left: A larvae of H. armigera that died of NPV on chickpea plant in India; note
the characteristic hanging stance. Right: A larvae of H. armigera that died of NPV
on cotton plant in India; note the characteristic hanging stance.

8. Granulosis Virus
• Develop either in the nucleus/cytoplasm/
tracheal matrix / epithelial cells of host
• Virions are occluded singly in small inclusion
bodies called capsules
• Rod shaped virion, Ds DNA
• Oval occlusion bodies about 200x400nm
• They enter through ingestion, similar to NPV
• Fat body is the major organ invaded
• Diseased larvae – less
active, flaccid, fragile, wilted prone to rupture in
later stages, death in
6-20 days

9. Western grapeleaf skeletonizer is a pest of grapes that periodically defoliates vineyards

10. Cytoplasm Polyhedrosis Virus
• Develop only in cytoplam of host
midgut epithelial cells
• Virions occluded singly in polyhedral
inclusion bodies, Ds RNA
• Average diameter is 60nm
• POBs range from 0.5-15µm in
diameter
• Infection confined to midgut and
does not spread to other tissues
• Infection not always lethal but shows
larval growth reduction
• Continuosly shed infective polyhedra
in faeces

11. Heterocampa guttivitta larva infected with
cytoplasmic polyhedrosis virus (CPV)

13. Large Scale Production
• In vivo
- applying the virus against the host insect in the field and collecting diseased or dead larvae
-producing the target insect in the laboratory on an artificial diet
• In vitro
- Baculovirus production in insect cell cultures

14. A clonal cell line Spex-II-A and a clonal cell line Hz-AM-1-1
infected with HaNPV, which established in the laboratory

16. Genetic Engineering

17. • Narrow Host Range
• Environmentally Safe, No Risk of Toxicity
• No Adverse Effects on Other Species, Insect
Pollinators remain unharmed

18. Drawbacks
• Chemical Pesticides cause more effective reduction
of insect population and better crop protection
• Viral pesticides require more involved monitoring
system
• The number of application on a particular area is
more than chemical pesticides
• Viral pesticides cannot be stored for longer periods
of incubation
• Producers more comfortable and experienced with
use of chemical pesticides- marketing problems

19. References
• Baculoviruses as biopesticides
-Seema Mishra (Eukaryotic Gene Expression Laboratory, National Institute of
Immunology, Aruna Asaf Ali Marg, New Delhi 110 067, India)
• Baculovirus Biopesticides
-Boguslaw Szewczyk*, Marlinda Lobo de Souza, Maria Elita Batista de
Castro, Mauricio Lara Moscardi and Flavio Moscardi (Department of
Molecular Virology, University of Gdansk and Medical University of
Gdansk)
www.biopesticideindustryalliance.org/microbialviruses.php
www.scribd.com/doc/78234955/22/b-3-Viral-Biopesticides
www.sciencedaily.com/releases/2010/08/100820133238.htm