Efficacy of entomopathogenic fungi in an integrated pest management plan for cucumber beetles in melons and pumpkins

View the project final report

• 2010 annual report

Commodities

• Vegetables: cucurbits

Practices

• Crop Production: biological inoculants
• Pest Management: biological control, biorational pesticides, disease vectors, integrated pest management, physical control
• Production Systems: organic agriculture

Spotted and striped cucumber beetles (Diabrotica undecimpunctata and Acalymma vittata) are significant pests of cucurbits and are especially damaging in the southeast where they overwinter and have multiple generations. These beetles damage pumpkin, cantaloupe/muskmelon, summer squash and cucumber by feeding on the fruit directly and vector bacterial wilt caused by Erwinia tracheiphila which can kill the vines. In 2002, a working group composed of growers, extension agents, researchers and industry in Tennessee addressed pest problems in cucurbit crops. One result of the group’s efforts was the Tennessee Pest Management Strategic Plan for Cucurbits. This plan identified the transmission of bacterial wilt as the most significant problem facing cucurbit production, and management of the cucumber beetle vectors was the top priority. Currently, cucumber beetles are managed conventionally with pyrethroids, neonicotinoids, carbamates and organochlorines. These compounds are effective but may have negative impacts on aquatic organisms, beneficial insects and pollinators and contaminate groundwater. A good integrated pest management plan is sustainable and focuses on a variety of tactics using cultural, physical and biological controls. Organic growers are limited in what they can use for cucumber beetle management and need alternatives, and consumers increasingly demand vegetables that are grown chemical-free. Biopesticides are made from naturally occurring microorganisms that kill the insect pest while preserving beneficial insects. This project will evaluate the efficacy of three different mycoinsecticides in reducing cucumber beetle damage and offer guidelines to creating an IPM plan that is sustainable for small to medium sized growers.

1. To examine the efficacy (measured by infection and mortality) of three entomopathogenic fungi (Beauveria bassiana, Metarhizium anisopliae and Isaria fumosorosea) on cucumber beetles (Diabrotica undecimpunctata) in a controlled laboratory setting.
2. Assess the efficacy of the three fungi on cucumber beetles on melon and pumpkin in the field and compare to carbaryl (a conventional standard) and row covers (cultural control method) and an untreated check in the field.
3. Determine the effects of the three biopesticides and carbaryl on non-target insect populations in the field.