Survey of predators and sampling method comparison in sweet corn

Area of Science:

• Agricultural Entomology
• Integrated Pest Management (IPM)
• Beneficial Insect Ecology

Background:

• Natural predation is crucial for integrated pest management (IPM) but often underestimated due to quantification challenges.
• Accurate monitoring of natural predators is essential for effective sweet corn pest management.
• Previous methods for predator assessment in sweet corn have limitations in reliability and precision.

Purpose of the Study:

• To identify the most abundant natural predators in New York sweet corn agroecosystems.
• To compare the efficacy of three sampling methods for monitoring key predator populations.
• To establish a reliable method for incorporating natural predation into sweet corn IPM.

Main Methods:

• Conducted a multi-year predator survey on sweet corn (Zea mays L.) in New York.
• Compared nondestructive field counts, destructive sampling, and yellow sticky cards for predator monitoring.
• Analyzed data to assess precision and accuracy of each sampling method for adult and immature predators.

Main Results:

• Identified 13 predator species, with Orius insidiosus, Coleomegilla maculata, and Harmonia axyridis being most abundant.
• Field counts correlated well with destructive counts but showed bias for smaller insects.
• Yellow sticky cards were unreliable, underrepresenting immatures and showing biased attraction to certain adult species.

Conclusions:

• Nondestructive field counts provide the most precise and accurate method for monitoring key sweet corn predators.
• Field counts are cost-effective and efficient, supporting their use in IPM research.
• Future research should utilize field counts for predicting natural predation in sweet corn systems.