BIOLOGICAL CONTROL OF INSECT & PESTS

Biological control is a component of an integrated pest management strategy and is an environmentally sound and effective means of reducing or mitigating pests and pest effects through the use of natural enemies.

DYNAMICS OF NATURAL POPULATIONS

o        Pop= Birth + Migration-Death

o        Biotic potential

o        Environmental resistance

w       Abiotic factors (Weather, food, shelter)

w       Biotic factors (Predators, parasites, Pathogens)

BIOLOGICAL CONTROL

o        Natural control vs. Biological control

o        Why biological control ?

w       Ecologically sound

w       Less expensive

w       Non polluting

w       Effective

EVALUATION OF EXISTING NATURAL ENEMIES

o        Survey the existent fauna

•          Kinds of natural enemies

•          Population fluctuation of pest and natural enemies

•          Synchronization studies

o        Quantification of  NE impact

•          Cages and barriers

•          Exclusion

•          Direct  observation

•          Use of radio tracers

PREDATORS

o        Free living

o        More than one prey are consumed

o        Less host specific

o        Coccinellids, Carabids, ants, Lace wings, Syrphids, Damsel bugs, Reduviid bugs

PARASITOIDS

   

MICROBIAL AGENTS

l  Very effective  natural control

l  Weather dependant

l  Bacteria

–        Bacillus

l  Fungi

–        Beauveria

–        Metarhyzium

l  Nematodes  

Viruses

v  Entry through feeding or punctures

v   Polyhedral viruses

INTRODUCTION

p        Classical bio control

p        Better for introduced pests

p        Area for Exploration

P        Origin of pest

P        Environmental conditions

p        Steps

P        Importation

P        Evaluation

P        Release

P        Post release evaluation

AUGMENTATION

l  Inoculative releases

When an effective natural enemy is affected due to

v  climate

v   host scarcity

v  Lack of synchronization

v  Inundative releases

v   Biological insecticide

v   May not need all the attributes of an ideal   natural enemy

v   Able to inflict high mortality

v   Mass multiplication facilities are required

CONSERVATION STRATEGIES

q        Protection and maintenance of natural enemies thorough

m      Use of Supplemental Foods

m      Use of Reduced or Selective Insecticide Modifying Vegetation Diversity

m      Use of Semiochemicals

m      Use of Supplemental Refuges

m      Impact of secondary natural enemies

m      Negative interactions with host pant resistance

m      Improvement of natural enemies

m      Cultural practices

m      Provision of alternate hosts