Bt sweet corn and selective insecticides: impacts on pests and predators.

Area of Science:

• Agricultural Entomology
• Insect Pest Management
• Biological Control

Background:

• Sweet corn (Zea mays L.) faces significant yield losses from insect pests.
• Current pest control relies heavily on broad-spectrum insecticides, harming beneficial insects.
• Natural predators offer partial pest control but are susceptible to non-selective insecticides.

Purpose of the Study:

• Evaluate the impact of newer pest control products on beneficial insects in sweet corn.
• Compare the efficacy and non-target effects of Bt sweet corn, indoxacarb, and spinosad against traditional insecticides.
• Determine the feasibility of integrated pest management strategies in sweet corn.

Main Methods:

• Field trials were conducted to assess the toxicity of different insecticides and Bt sweet corn to key predators.
• Evaluated pest control efficacy and impact on predator populations (Coleomegilla maculate, Harmonia axyridis, Orius insidiosus).
• Compared effects of insecticide material, application frequency, and rate on pests and predators.

Main Results:

• Transgenic Bt sweet corn, indoxacarb, and spinosad showed lower toxicity to major sweet corn predators than lambda cyhalothrin.
• Indoxacarb exhibited moderate toxicity to coccinellids; spinosad and indoxacarb were somewhat toxic to O. insidiosus nymphs.
• Bt sweet corn and spinosad provided effective lepidopteran pest control, comparable or superior to lambda cyhalothrin.

Conclusions:

• Newer pest control options like Bt sweet corn, indoxacarb, and spinosad are compatible with beneficial insects.
• These products facilitate integrated pest management, enhancing conservation and augmentation biological control in sweet corn.
• Selective pest control strategies are crucial for sustainable sweet corn production.