Biological control of pest

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1. Biological control of pest . 1

2. Biological Control Definition “ The use of living organisms to suppress the population of a specific pest organism , making it less abundant or less damaging than it would otherwise be” 2

3. What Are Natural Enemies? Natural enemies are living organisms that: Kill pests Decrease pest reproductive potential Compete with pest organisms for use of your plants. 3

4. Who kills Pests? Predators Parasites Pathogens Sterilization 4

5. Types of biological pest control There are three basic types of biological pest control strategies: importation (sometimes called classical biological control), augmentation and conservation. Importation: Importation involves the introduction of a pest's natural enemies to a new locale where they do not occur naturally. 5

6. Classical biological control is long lasting and inexpensive. Other than the initial costs of collection, importation, and rearing, little expense is incurred. When a natural enemy is successfully established it rarely requires additional input and it continues to kill the pest with no direct help from humans and at no cost. However importation does not always work. It is usually most effective against exotic pests and less so against native insect pests. The reasons for failure are not often known but may include the release of too few individuals, poor adaptation of the natural enemy to environmental conditions at the release location, and lack of synchrony between the life cycle of the natural enemy and host pest. 6

7. Augmentation Augmentation involves the supplemental release of natural enemies, boosting the naturally occurring population. 7

8. Conservation enhance conditions for existing natural enemy survival and reproduction. 8

9. Biological control agents 9 Predators Predators are mainly free-living species that directly consume a large number of  prey  during their whole lifetime. Ladybugs , and in particular their larvae which are active between May and July in the northern hemisphere, are voracious predators of  aphids , and will also consume  mites ,  scale insects  and small  caterpillars . Dragonflies  are important predators of mosquitoes.

10. Lady bird beetle (ladybug) Larva eating aphids

11. Parasitoids Parasitoids lay their eggs on or in the body of an insect host, which is then used as a food for developing larvae. The host is ultimately killed. Most insect  parasitoids  are wasps or  flies , and usually have a very narrow host range. 11

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15. Pathogen Pathogenic micro-organisms include  bacteria ,  fungi , and  viruses . They kill or debilitate their host and are relatively host-specific. Various  microbial  insect diseases occur naturally, but may also be used as biological pesticides 15

16. 16 Insect Mummy covered with Fungal Spores Infected Larva Viral fluid

17. sterilization 17

18. advantages of Biological Control: high level of control at low cost self-perpetuating at little cost after initial effort very few harmful effects on man, environment etc some NE’s reproduce rapidly some NE’s search out hosts some NE’s survive even at low host densities 18

19. Disadvantages of Biological Control Not effective against Direct Pests where any damage is unacceptable Some level of damage occurs and must be acceptable Must be implemented over large areas May take years to become effective 19