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Insect Management

Your Insect Management Program

Insect pests can reduce yield, quality and profit. However, it is not easy to know how many is too many insects. A few may not cause much damage, but add a few more and they could start limiting yields. Typically, fields should be treated when insects reach or exceed established thresholds. These thresholds vary by state, and each grower must also decide how many insects are tolerable before treatment is necessary. It is important to remember that insects can vector certain diseases, such as Tomato Spotted Wilt Virus. Also, for plants that are stressed, a lower treatment threshold should be used.

Tips For Improving Your Program:
• Scout for possible problems. Insects, such as the velvetbean caterpillar, can be easily controlled but will reduce yields if not controlled in a timely fashion.

• Know the weather conditions that favor outbreaks. Hot, dry conditions are preferred by lesser cornstalk borers; wet periods favor southern corn rootworm.

• Make foliar insecticide decisions on a field-by-field basis. Use insecticides only when necessary. High-risk situations may justify preventative applications to control thrips or soil insects.

Weigh Insecticide Decisions Carefully
As with other pests, correct identification of the insect problem is critical to control. Indiscriminate use of insecticides wastes money and can create problems later in the season. The benefits of an insecticide application must be weighed carefully against potential damage to beneficial insects, secondary pest outbreaks and development of resistance. The state of growth, variety and duration of feeding damage should be factored into treatment decisions.ons.

New Pests Have Become Troublesome
Recently, three insect pests have become troublesome, although not always widespread problems each year. The first, the granulate cutworm, is a foliage feeder that hides in debris on the soil surface during the day and crawls up on the plant to feed at night. The second pest, now almost a perennial problem, is the three-cornered alfalfa hopper (TCAH). Efforts to develop treatment thresholds for this pest have so far not produced a useful tool. Growers should evaluate potential damage to beneficials as well as populations of TCAH before spraying.

The third pest is the burrower bug, a cousin of the stinkbug. When pods begin to develop, they burrow around them and “sting” the peanut seed, leaving damage only evident when it is shelled and the skin removed.

Scouting peanut fields on a regular basis throughout the season is the surest way to identify what insect pests are present and when they reach treatable levels.


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