Ph. D. Scholar Department of Entomology Indira Gandhi Krishi Vishwavidyalaya Raipur (Chhattisgarh)

1. Genetics of Ideal Traits in Biocontrol
Agents for Introgressing and for
Progeny Selections
Prepared By
Aaliya Afroz
Ph. D. Scholar
Dept. of Entomology, IGKV, Raipur

2. Introduction
• Insect pest problems in agriculture have shown a considerable shift
during first decade of twenty-first century due to ecosystem and
technological changes.
• Biological control has been accepted as an effective,
environmentally non-degrading, technically appropriate,
economically viable and socially acceptable method of pest
management.
• It aims at suppression of insect pests of crops or other harmful
organisms by using their natural enemies (parasites, predators and
pathogens).

3. Contd.
• Recent research has shown that pesticide-resistant parasites
selected in the laboratory can be established in the field and
enhance IPM programs.
• Both laboratory selected or genetically engineered natural enemies
play an expanded role in IPM programs and the reduction of
pesticide use.
• Genetic manipulation of natural enemies of insect pests offers
promise of enhancing their efficacy in agricultural cropping systems.

4. Characters focused in Genetic Improvement
of Natural Enemies of Insects
• Improved climatic tolerances
• Improved host finding ability
• Changes in host preference
• Improved synchronization with the host
• Insecticide resistance
• Non-diapause
• Induction of thelytokous reproduction.

5. Emerging technologies in augmentation of
natural enemies
a. Artificial selection
b. Hybridization or, use of Heterosis
c. Use of Biotechnology (recombinant DNA (rDNA) techniques)

6. Artificial Selection:
• Selection is employed to find genetically superior natural enemies.
• Example-
• A host tolerant strain of Heterorhabtidis bacteriophora Poinar
designated as ISS was discovered in Negev desert, Israel in 1996 and
was found superior to HP88, a commercial available strain of
Heterorhabtidis bacteriophora.

7. Examples
1. Development of endosulfan tolerant strain of Trichogramma –
Endogramma ((Jalali et al., 2006). )
2. Developing multiple-pesticide tolerant strain of Trichogramma –
• A multiple insecticides tolerant strain of T. chilonis (MITS-TC), tolerant to
endosulfan, monocrotophos and fenvalarate was developed and was
field evaluated against Helicovarpa armigera
3. High temperature tolerant Trichogramma
• Strains of T. chilonis namely TcUPI and TcUP2, were identified as tolerant
to high temperatures of 32-40oC and with high biotic potential (65%
females and fecundity of 116).
• Such strains could be used against sugarcane borers in hot weather
conditions (NAIP-ICAR2012).

8. 4. Monocrotophos resistant Green lace wing, Chrysoperla carnea:
• Patel and Yadav (1995) has reported the monocrotophos resistant
strain of C. carnea.
5. Genetically manipulated predatory mite, Metaseialus occidentalis:
• Metaseialus occidentalis is a very versatile mite predator does best
in warm weather (80° to 110° F) and tolerates low humidity of
inland valleys of California, USA.

9. Hybridization
The transfer of beneficial genes by hybridization can provide a powerful approach
for genetic improvement.
Examples:
Development of Hybrid Trichogammatid
• Hybrid T. chilonis strain was developed to express tolerance to both high
temperature and repetitive pesticide sprays. (Jalali and Venkatesan 2005).
Hybrid Chrysoperla carnea:
• Patel and Yadav (2000) has studied the estimation of heterosis and
heterobeltiotis for some important traits of hybrids of C. carnea.

10. Recombinant DNA (rDNA) techniques
• In this technique desirable gene(s) must be identified, cloned and
inserted into natural enemies, be incorporated into their genome,
be stable, be expressed in the appropriate tissues and at the
appropriate time, and transmitted to the progeny.

11. Recombinant DNA technique

12. Contd.
Genetic transformations can be deployed in natural enemies to:
1. Modify the genome of natural enemies
2. Change the sex ratio
3. Cryopreservation
4. Develop genetic linkage maps
5. Identify biotypes
6. Improve artificial diets
7. Monitor establishment and dispersal
8. Parentage analysis and genetic changes

13. Examples
• Genetic engineering in Bacillus thuringiensis
• Genetic engineering in entomopathogenic fungi
• Genetically engineered Metarhizium anisopliae
• Genetic engineering in entomopathogenic virus

14. Genetic engineering in Bacillus thuringiensis
• To expand the specificity to other pests, Bt toxin genes from
different subspecies were cloned into plasmids & introduced into
host strain.
• Cry1A.105, CryIAb, CryIF, Cry2Ab, Cry3Bb1, Cry34Ab1, Cry35Ab1,
mCry3A, and VIP are the Bt genes incorporated to hosts like corn,
cotton etc.
• The activity of Cry toxins can be enhanced (that is by enhancing
toxicity) by genetically engineering genes and expressing proteins
like serine protease inhibitors, chitinases, Cyt toxins.

16. Genetic engineering as a tool for improving desirable traits in
entomopathogenic fungi

17. Genetic engineering in entomopathogenic virus
• A heat inducible C. elegans heat- shock gene, hsp 70A, has been
transferred into Heterorhabtidis bacteriophora HP88.
• The 70- KDa heat shock protein encoded by the gene enables cells
to eliminate or renature proteins damaged by high temperatures.
• A trait of heat tolerance was transferred from Heterorhabtidis
bacteriophora strain ISS to wild strain HP88.
• The hybrid progeny were confirmed by use of a marker mutant
isolate and by backcrossing. More importantly, there was no loss of
fitness in the hybrid progeny relative to the parental strain.

18. Processes of Developing Genetically Modified Natural Enemy

19. Constraints to initiate a genetic improvement
project of naturel enemies
• Improper identification of the trait needing improvement could lead
to an expensive and time-consuming project of little practical value.
• Genetic variability must be available upon which one can select if
using artificial selection.
• Improved naturel enemy must be documented to be effective in the
field.
• Cost of the project should be justified by the benefits achieved.

20. CONCLUSIONS
• Though the use of predator and parasitoids has no hazardous
environmental impact but their efficacy under various conditions
limits their usages.
• The improvement of their potency can boost their uses over the
chemical mode of pest control.
• A genetic improvement can be useful when the natural enemy is
known to be a potentially effective biocontrol agent