Superheroes? Beneficial insects help protect plants from pests

By Pat Melgares, K-State Research and Extension news service

MANHATTAN, Kan. – In the insect world, superheroes come in small sizes. Often as small as one-fiftieth of an inch, in fact.

But don’t let their size fool you: Kansas State University entomologist Raymond Cloyd said beneficial insects – also called biological control agents or natural enemies – are mighty predators, attacking insect or mite pests that can rob farmers of bountiful harvests, or greenhouse producers of marketable ornamental plants.

“Beneficial insects and mites are the good guys and gals taking care of the bad guys and gals,” Cloyd said. “They are a natural way to regulate or manage insect or mite pest populations in farming systems, greenhouses and nurseries.”

Using biological control agents to reduce crop losses due to pests may also reduce the use of insecticides and miticides, he said.

“One of the problems we’re encountering is pesticide resistance among certain target insect and mite pest populations,” Cloyd said. “If we can incorporate biological control agents into crop production systems, we can reduce the selection pressure placed on insect or mite pest populations by reducing the amount of pesticides that are applied.”

“We have a program in Wamego (Kansas) where we’ve been implementing biological controls for three years with minimal to almost no inputs from pesticides. The program has been extremely successful.”

Another example of success: Cloyd has been working with a producer in Courtland, Kansas for eight years in which predatory mites (Phytoseiulus persimilis) have been released into a hoop house tomato production system to manage two-spotted spider mite (Tetranychus urticae) populations. In those eight years, no miticides have been applied, he said.

In late 2022, Cloyd published an extension publication on the rove beetle (Dalotia coriaria), a soil-dwelling predator that is one-eighth of an inch long. Rove beetle larvae and adults feed on fungus gnat larvae (often found feeding on houseplants) and western flower thrips pupae (an insect pest that feeds on more than 500 species of host plants, including fruit, vegetable and ornamental crops).

“Rove beetle adults are very active and can fly,” said Cloyd, who has been studying the rove beetle for nearly 20 years. “Based on our research, the rove beetle is an effective biological control agent.”

This February, Cloyd has released two additional publications:

All three publications are available to view or order online from the K-State Research and Extension bookstore.

“These publications will enhance the existing portfolio of extension publications from K-State,” Cloyd said. “We don’t have many publications on individual biological control agents, so these publications will start filling that gap. The information will be extremely valuable to producers who are considering implementing a biological control program.”

“Biological control does work,” he added. “However, producers need a sound knowledge of insect and mite pest biology and ecology, and assistance from extension entomologists. I can tell you from my experience that biological control can be successful.”



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