At CSU’s Plant Environmental Research Center (PERC), the Specialty Crops Program manages three quonset hut greenhouses for blueberries, papayas, salad mix, strawberries, and vegetable starts. Common insect pest problems currently include aphids, two-spotted spider mites, and fungus gnats.
Aphids can be controlled with insecticidal soap, ladybird beetles, and lacewings. We tried introducing adult lacewings but had very poor results. They didn’t lay eggs as we had hoped, and so we resorted to introducing adult ladybird beetles which are presently dropping the aphid population quickly and laying eggs. Parasitoids have not been introduced at this time because they usually appear naturally and will help to maintain aphid levels after control is gained by the ladybird beetles.
Feltiella acarisuga, a predatory midge was introduced to the papaya greenhouse. It has successfully established and is providing good biological control of two-spotted spider mites. Phytoseilius persimilis, a predatory mite has also been introduced to control two-spotted spider mites and is widely used for this purpose.
Hypoaspis miles, a predatory mite, was introduced to control fungus gnat larvae in the potting media and is maintaining fungus gnats at low levels. The rove beetle (Atheta sp.), also a soil dwelling predator of fungus gnats and shore flies, is established in our potting medium and was not introduced.
At the Horticulture Research Center (HRC), common insect pests include flea beetles, cucumber beetles, squash bugs, and various species of caterpillars.
The use of transplants and floating row covers are preventive measures that can protect plants against flea beetles damage. Cabbage looper, Imported cabbage moth, and diamondback moth were present and controlled with Bt.
The Bt (Bacillus thuringiensis) should be sprayed in the evening since sunlight can break down the active ingredient. CSU Cooperative Extension has more information about Bacillus thuringiensis information on their website. We used a motorized, 3-gallon, backpack mounted mist blower to spray Bt on our sweet corn silks and the non-motorized backpack sprayer for the cole crops.
Other Sources of Information About Biocontrol and Integrated Pest Management
The Mountain West IPM Network is a pest management information network for Colorado and Wyoming. High Plains Integrated Pest Management has a website which provides current effective management options for insect and other arthropod pests, and for plant pathogens affecting all major field crops grown in Colorado, Montana, Wyoming, and Western Nebraska. See the University of California Statewide Integrated Pest Management Website for IPM research, educational resources, and pest management techniques. Cornell University also has an informative website called Biological Control: A Guide to Natural Enemies in North America.
Specialty Crop Program Grower Grants that involve integrated pest management include Biology and Management of Sap Beetle in Sweet Corn and Japanese Beetle Eradication from Palisade, Colorado.