Field Evaluation of Certain Pesticides Against the Cotton Bollworms with Special Reference to their Negative Impact on Beneficial Arthropods

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Field Evaluation of Certain Pesticides Against
the Cotton Bollworms with Special Reference to
their Negative Impact on Beneficial
Arthropods (2006 cotton season, Minia region,
Egypt)
Abdelrahman M. Younis, S.H. Hamouda, S.A.
Ibrahim, and Z.A. Zeitoun Plant Protection
Department Faculty of Agriculture Minia
University Minia, Egypt
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Introduction

• In Egypt, about half a million feddans are
  cultivated with cotton, representing 6 of all
  cultivated lands.
• Earias insulana and Pectinophora gossypiella are
  serious pests infecting cotton in Egypt.
• Economical yields are impossible to achieve
  without their chemical control.
• Chemical control of cotton pests costs 12.5
  million U.S. dollars.

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The pink bollworm Pectinophora gossypiella
damaged cotton bolls
adult
larva
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The spiny bollworm Earias insulana
damaged cotton boll
larva
adult
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Objectives

• To select the most effective pesticides against
  cotton bollworms.
• To study the indirect effect on seed cotton
  yield.
• To study the side effects on natural enemies.

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Materials Methods

• Seven pesticides were evaluated.
• Earias insulana and Pectinophora gossypiella.
• Gossypium barbadens, (Giza 80 Cotton, variety).
• Cotton field was divided into 32 plots of 175 m2
  each.
• 100 green bolls/plot were collected for recording
  the infestation and larval content before and
  after spray.

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• Number of predators in each plot was monitored
  using a sweep net technique (Southwood, 1978).
• Reduction percentages were calculated (Henderson
  and Tilton, 1955).
• Seed cotton yield for each plot was weighed.
• Data was analyzed using analysis of variance
  (Gomez and Gomez, 1984).

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Conclusion

• Synthetic pyrethroids exhibited the greatest
  efficiency in controlling bollworms.
• The Bt-bioproduct was significantly the least
  effective treatment in reducing bollworm
  infestations.
• Seed cotton yield was greater in pyrethroid
  treatments gt OP's Bt-bioproduct gt control.

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• The Bt-bioproduct resulted in the minimum
  negative impact toward beneficial arthropods.
• We suggest using gamma-cyhalothrin in rotation
  with the Bt-bioproduct to minimize the side
  effects on beneficials

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Acknowledgements

• Financial support for this project was provided
  in part by the Ministry of Agriculture, Egypt.
• Financial support to participate and present this
  manuscript was provided in part by Minia
  University, Minia, Egypt.