Rice Plant- and Leaf Hoppers

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Bio-control and Biopesticides in Rice IPM
Introduction Pest management is known as an
ecological approach to tackle pest problems
because here emphasis is on containing pests in
such a way that other biotic components of the
system such as natural enemies, human beings and
wild life are not harmed and environment is
preserved in general. Pest management also
underlines that pest control tactics should be
socially acceptable and within the reach of
farmers.
Earthworms victims of pesticide use
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In IPM different methods of pest control such as
resistant varieties, cultural methods, physical
methods, Biological and pesticides are integrated
to suppress pest populations. An IPM programme
should be basically based on conservation of
native natural enemies, cultural methods and
resistant cultivars and other management tactics
should be incorporated based on availability and
need.
IPM Concept
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Biological Control

• Biological control refers to use of natural
  enemies of pests such as parasitoids, predators
  and pathogens to suppress pest populations. Rice
  ecosystems are replete with natural enemies but
  these need to be conserved against harmful effect
  of pesticides.
• Likewise, biopesticides like plant extracts or
  pathogens are also used to contain pests.
  Parasitoids such as Trichogramma are also used to
  suppress borer pests.

Spider- Prolific predator
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• Predators
• Spiders, predatory bugs, predatory beetles,
  predatory crickets and grasshoppers take heavy
  toll of rice pests.
• Spiders Spiders are dominant and most common
  predators in rice ecosystem. They are voracious
  feeders of leaf and planthoppers, leaf eating
  caterpillars and adult stem borers. Spiders
  consume 5-15 insects a day depending upon their
  size.

Spiderlings in rice field
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Water strider Adults and nymphs of water strider
prey on rice hoppers, moths and larvae that drop
on to water surface. Each water strider consumes
5-10 prey daily.
Water strider
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• Predatory beetles
• Ground beetles feed on larvae of leaf folder,
  and planthoppers. Each predator can consume 3-5
  larvae per day. Rove beetles feed on larvae of
  leaf folder and hairy caterpillar, and
  planthoppers. Likeiwse, lady bird beetles prey on
  leaf folder larvae and planthoppers.

Rove beetle
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Predatory crickets and grasshoppers Sword-tailed
crickets are egg predators and consume eggs of
several rice pests. Likewise meadow grasshoppers
feed on eggs of rice bug and stem borer, and
nymphs of planthoppers.
Predatory cricket
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• Vertebrate predators Predators like sparrows,
  mynahs, ducks, frogs and fish are also reared in
  rice fields and they heavily consume planthoppers
  and other pests, besides providing extra income
  to farmers.

Sparrow
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• Parasitoids
• Parasitoids are tiny insects which feed on eggs,
  larvae or pupae of pests. Eggs parasitoids of
  stem borer and leaf folder such as Trichogramma,
  Telenomus and Tetrastchus egg parasitoids of
  leaf and planthoppers like Gonatocerus and
  Anagrus, and larval parasitoids such as
  Apanteles, Bracon, Stenobracon play very
  important role in pest suppression under natural
  field conditions.

Stenobracon parasitoid
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• Inundative releases of insectary reared egg
  parasitoid Trichogramma (Trichocard) are also
  undertaken to contain stem borer and leaf folder
  incidence. Trichogramma japonicum and T. chilonis
  is released against yellow stem borer and leaf
  folder, respectively _at_ 1-1.5 lakh/ha/week for 6
  weeks starting 30 days after transplanting.
• These releases act like application of
  insecticides and control is achieved through
  released individuals only and not through their
  progeny.

Braconid wasp
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• Pathogens
• Entomopathogenic fungi like Beauveria,
  Metarhizium, Entomophthora also play important
  role in suppressing populations of planthoppers
  and other pests. Likewise, entomogenous nematode,
  Steinernema carpcapsae and nucleopolyhedrosis
  virus (NPV) have been found to be effective
  against rice pests.

NPV infected insect larva Courtesy
http//butterflybreeders.com
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• Biopesticides
• Bacteria, Bacillus thuringiensis (Bt) is
  effective against lepidopteran pests.
• Neem products like neem seed kernel extract
  (NSKE) is effective against planthoppers and
  other foliage feeders.
• Conservation of natural enemies
• Ensure need based application of pesticides
• Avoid use of broad spectrum pesticides
• Dont treat area having natural enemy abundance.

Conserve natural enemies
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• Lets Sum up
• Biological control refers to use of natural
  enemies of pests to suppress pest populations.
• Predators like spiders, predatory bugs, predatory
  beetles, predatory crickets and grasshoppers take
  heavy toll of rice pests.
• Parasitoids are tiny insects which feed on eggs,
  larvae or pupae of pests. Trichogramma is an
  important egg parasitoid of rice stem borer and
  leaf folder.
• Inundative releases of insectary reared
  Trichogramma (Trichocard) are also undertaken to
  contain stem borer and leaf folder incidence.
• Fungi like Beauveria, Metarhizium, Entomophthora
  play important role in suppressing populations of
  planthoppers and other pests.
• Nematode, Steinernema carpcapsae and
  nucleopolyhedrosis virus (NPV) have also been
  found to be effective against rice pests.
• Biopesticides such as Bacillus thuringiensis
  (Bt) and neem seed kernel extract (NSKE) are
  effective against rice pests.
• Conservation of natural enemies can be ensured
  through need-based application of selective
  pesticides.