1. S.M.Joshi College, Hadapsar.
Tamboli A.Z.
Department of Zoology
S.M.Joshi College, Hadapsar.
F.Y .B.Sc.
Pests and Pest Control

2. Pest Control Is An Everlasting Problem
How does an organism become labeled as a pest species?
Pest control: winning the battles but losing the war.
Designing better mouse traps.

3. A Pest Defined
Technically, any organism (bacteria, fungi, plant, animal) that has a negative effect on human health or economics (food).
Realistically, any organism we don’t want around (factors in convenience and esthetics).

4. Integrated Pest Management (IPM)
An approach to controlling pest populations using all suitable methods - chemical and ecological.
The goal is to brings about long-term management of pest populations that also have minimal environmental impact

5. Pesticides (Biocides)
Insecticides (dah!)
Herbicides (not just the weedy plants)
Rodenticides (mammalicides)
Fungicides (mildews and rusts)
Acaricides (ticks and mites)
Bacteriocide (e.g. antibiotic)

6. Pesticide “Improvements” (?)
Second-generation pesticides
Organic chemical (organochlorines).
Used after WWII (presently in developing countries)
Synthesis begins with petroleum (“oil”)
Mechanism of actions often unknown.
Bioaccumulation & Biomagnification.
Toxic to animals (humans) and agricultural plants.
Pests developed resistance.

7. Resistance to Pesticides
Chemical pesticides lose effectiveness
Resistant pest populations produce next generations

8. Some Examples of Insect Food Chains

9. Human Health Effects
Acute: high dose, short-term response, rapid onset (headache, nausea, vomiting, respiratory failure, death). Agricultural workers suffer acute poisoning during pesticide application.
Cronic: low-dose, long-term exposure, outcome takes many years before noticed (cancer, dermatitis, neurological disorder, birth defects, sterility, endocrine system disruption, immune system depression). Neighborhoods downwind of agricultural use; farm families; the innocent.

10. Environmental Effects
Bioconcentration:
Movement against a concentration gradient; typically fat soluble.
Biomagnification:
Movement through the food chain to higher trophic levels; typically persistant.
Bioaccumulation:
Combined effect of both; chemicals are typically fat soluble and persistant.

11. The DDT Case Study 1938; dichloro-diphenyltrichloroethane (DDT)
Extremely toxic to insects, but seemed nontoxic to humans and other mammals.
Cheap.
Broad-spectrum and persistent
Effective for disease prevention (typhus fever, malaria)
Expanded agricultural production
Paul Muller awarded Nobel prize in 1948

12. Natural Pest Control Cultural control Control by natural enemies
Genetic control
Natural chemical control

13. Insect Life Cycle

14. Cultural Control Get rid of the alternative host!

15. Control by Natural Enemies

16. Genetic Control
Plants or animals are bred to be resistant to the attack of pests.
Chemical barriers.
Physical barriers.
Introduction of genes into crops from other species: transgenic crops (Bt)
Sterile males are released into pest population.

17. Natural Chemical Control
Manipulation of pests’ hormones or pheromones to disrupt the life cycle.
Japanese beetle trap.