Vegetable Crop Insects – July 12, 2013

Joanne Whalen, Extension IPM Specialist; jwhalen@udel.edu

Kudzu Bug on Succulent Beans
Now that the first adults have been detected in the state, it is important that you know how to identify all life stages. As indicated last week, initial findings from host preference studies from Georgia indicate that they do not prefer non-soybean beans, but will occur on them. More information will be available this fall on host preference. In the meantime, you will want to scout succulent beans to see if this trend is true in our area. We may have to use the information developed for soybeans this season to help us make management decisions in succulent beans if the need arises. We will keep you posted of any new finds as well as new management information as it is developed

kudzubug1Adult kudzu bug

kudzubug2Kudzu bug egg mass and nymphs

Melons
Continue to scout all melons for aphids, cucumber beetles, and spider mites. Be sure to read all labels carefully for rates and restrictions since some materials, especially miticides are restricted to only one application as well as ground application only.

Lima Beans
Be sure to scout fields for leafhoppers, spider mites as well as plant bugs and stink bugs. As soon as pin pods are present, be sure to watch carefully for plant bug and stinkbug adults and nymphs. As a general guideline, treatment should be considered if you find 15 adults and/or nymphs per 50 sweeps. The higher rates of labeled products will be needed if stinkbugs are the predominant insect present.

Peppers
Depending on local corn borer trap catches, sprays should be applied on a 7 to 10-day schedule once pepper fruit is ¼ – ½ inch in diameter. Be sure to check local moth catches in your area by calling the Crop Pest Hotline (instate: 800 345-7544; out of state: 302 – 831-8851) or visit our website at http://agdev.anr.udel.edu/trap/trap.php . At this time, you will also need to consider a treatment for pepper maggot.

Potatoes
Continue to scout fields for Colorado potato beetle, leafhoppers, and aphids. Controls will be needed for green peach aphids if you find 2 aphids per leaf during bloom and 4 aphids per leaf post bloom. This threshold increases to 10 per leaf at 2 weeks from vine death/kill. If melon aphids are found, the threshold should be reduced by half.

Snap Beans
Continue to sample all seedling stage fields for leafhopper and thrips activity. As a general guideline, corn borer sprays are needed at the bud and pin stages on processing beans. Additional sprays may be needed after the pin spray on processing beans. Since trap catches can change quickly, be sure to check our website for the most recent trap catches and information on how to use this information to make a treatment decision in processing snap beans after bloom.

After the pin spray on processing beans, the spray schedule will be determined by a combination of both moth catches and field scouting:
http://agdev.anr.udel.edu/trap/trap.php

http://extension.udel.edu/ag/insect-management/insect-trapping-program/ecb-and-cew-moth-catch-thresholds-for-processing-snap-beans/

Sweet Corn
Continue to sample all fields from the whorl through pre-tassel stage for corn borers, fall armyworm and corn earworms. A treatment should be applied if 15% of the plants are infested with larvae. The first silk sprays will be needed for corn earworm as soon as ear shanks are visible. Be sure to check both blacklight and pheromone trap catches since the spray schedules can quickly change. Trap catches are generally updated on Tuesday and Friday mornings You can check our website (http://agdev.anr.udel.edu/trap/trap.php and http://extension.udel.edu/ag/insect-management/insect-trapping-program/action-thresholds-for-silk-stage-sweet-corn/) or you can call the Crop Pest Hotline (in state: 800-345-7544; out of state: 302-831-8851). Since fall armyworm feeds deep in the whorls, sprays should be directed into the whorls and multiple applications are often needed to achieve control.

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