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Commercial Horticulture > Comm Hort Blog > Posts > COLORADO POTATO BEETLE MANAGEMENT IN VEGETABLES

This article was prompted by some concerns about Colorado Potato Beetle (CPB) in commercial and home vegetable gardens. Did you know that the original host plant for CPB was buffalo bur (Solanum rostratum)? Potato really became one of the favorite food plants for CPB much later during the mid-1800s. Anyway, CPB feeds on potatoes, eggplants, pepper, tomatoes and a number of other plants. Life stages of the insect are shown in the pictures below. Reddish caterpillars and the adult beetles are voracious foliage feeders. CPB overwinters as adult in soil just as many other beetles do. Eggs are laid in clusters of 40 or more underside of leaves. The degree day model for CPB is shown in the Table 1. Sample 5 plants from 5 different locations within a large field of crops and look for eggs at the field edges. For adult and larval stages, use a sweep net with 25 sweeps staring especially at the field edges. The fourth instars drop to the ground to pupate meaning control measures have to applied timely when the larvae are small and feeding on the foliage.

Management of CPB in the backyard:
· Applying straw mulch around plants appears to interfere with migration of adult beetles.
· Because CPB has resistance to many insecticides, crop rotation is a powerful tool in IPM for this pest.
· Potato plants may be used as a perimeter trap crop around tomatoes (main crop). Two rows of early potatoes around tomato could attract beetles away. Control the beetles (by insecticidal or alternative methods) in the trap crop otherwise there CPB could become a greater problem.
· Insecticidal control for home gardens: Bifenthrin (waiting period or PHI = 7 days), lambda-cyhalothrin (PHI = 5 days), esfenvalerate (PHI = 7 days). Always read label of insecticide before & after purchase and always rotate insecticides because CPB has cross-resistance to many insecticides. Bacillus thuringiensis (var. tenebrionis or san diego), neem and pyrthrum are effective against small larvae and help protect the natural enemies. For more information, refer to the ACES IPM Guide for Home Garden Vegetables (IPM-1305).
· Contact a Regional Extension Agent at the nearest County Extension Office for more information about home garden insect management and to consult on restricted use pesticides.

  
Management of CPB on commercial vegetable farms:
· In general, do not apply one product  in repeat sprays. If you notice inefficacy of one product then use a different chemistry.
· In some states, CPB resistant to Group 3A insecticide  (esfenvalerate, permethrin, and endosulfan) have been reported. Growers in Alabama should also be cautious using the above 3A insecticides although resistant populations may not be present.
· Alternative chemistry: Spinetoram (Radiant) - a Group 5 insecticide is very effective.
· Systemic insecticides of Group 4A (imidacloprid, acetamiprid, thiamethoxam) are effective. Dinotefuran (Venom) is a new effective product.
· For an insecticide efficacy chart and complete list of insecticides for CPB management, refer to the 2010 Vegetable Crop Handbook. Use distantly related insecticides in rotation.
 

 

Ayanava Majumdar
Extension Entomologist
bugdoctor@auburn.edu


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