Scouting Notes - June 2008

Know compatibility of natural enemies and pesticides. The use of natural enemies with pesticides depends on whether the natural enemy is a predator or parasite; the particular natural enemy species and its life stage; and the pesticide rate, timing and mode of action.

University of Connecticut Extension horticulturist and greenhouse IPM specialist Leanne Pundt said pesticides are most harmful to natural enemies by direct contact. Pesticides can also harm biological control agents by killing their host insect or mite, which eliminates the control agent’s food source. Pesticide residual activity may repel a natural enemy so it cannot find its food source.

Sublethal pesticide effects also occur, including effects on reproduction, survival, sex ratio and ability of the natural enemy to find food. Pesticides harmful effects may not be due to the active ingredients, but to inert ingredients such as carriers or solvents.

For more: Leanne Pundt, University of Connecticut, (860) 626-6240; leanne.pundt@uconn.edu; www.negreenhouseupdate.info.

Trap plants for pest control. Researchers at Central Maryland Research and Education Center received a grant from the Association of Specialty Cut Flower Growers to study the effectiveness of using trap plants as a pest-control method in cut flower production. Cut flower crops and pests for the study are: zinnia and marigold for Japanese beetles, snapdragon and cleome for harlequin bugs; and sunflower for cucumber beetles.

The trap plants considered include: roses and hibiscus for Japanese beetle; candytuft for cucumber beetle; and colewort for harlequin bug. Trap plants will be treated with imidacloprid or dinotefuran.

For more: Stanton Gill, Central Maryland Research and Education Center, (301) 596-9413; sgill@umd.edu; http://ipmnet.umd.edu/ipmupdte.htm.

Scout for thrips if color shows. Thrips populations can explode when temperatures increase inside a greenhouse or when more pollen is available.

Michigan State University extension district IPM educator Dean Krauskopf said shorter generation times coupled with an increased food supply means more thrips. He recommends using yellow or blue sticky cards to detect increases in thrips populations.

Thrips do not fly well, so place cards close to the foliage. Move cards to new locations as well as up and down in the same locations to make sure accurate samples are taken.

For more: Dean Krauskopf, Michigan State University Extension, (248) 347-0269; krauskop@msu.edu.

Reports focus on miticide, nematicide markets. Kline & Co., a worldwide research and consulting firm, published separate reports on the U.S. miticide and nematicide markets.

“Miticides 2007: U.S. Market Analysis and Opportunities” is an analysis of infestations, treatment methods and chemicals used to treat mites on major field and specialty crops. “Nematicides 2007: U.S. Market Analysis and Opportunities” covers four crop categories and 16 crop markets.

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For more: Kline & Co., (973) 435-6262; www.klinegroup.com.

June 2008