Vegetable Crop Insects – August 31, 2012

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

Cabbage
Continue to sample for cabbage looper, diamondback larvae, fall armyworm, beet armyworm and Harlequin bug. Be sure to scout and select controls options based on the complex of insects present in the field.

Lima Beans
Continue to scout for stink bugs, lygus bugs, soybean loopers, beet armyworm and corn earworm. Moths can still be found laying eggs in fields. Be sure to sample for corn earworm larvae as soon as pin pods are present. A treatment will be needed if you find one corn earworm larvae per 6 ft-of-row.

Peppers
At this time of year, corn borer, corn earworm, beet armyworm and fall armyworm are all potential problems in peppers. So be sure to select the material that will control the complex of insects present in the field. Be sure to check local moth catches in your area by calling the Crop Pest Hotline (in state: 800-345-7544; out of state: 302-831-8851) or our webpage at http://ag.udel.edu/extension/IPM/traps/latestblt.html. We continue to see aphid populations increasing, especially in fields where pyrethroids have been used on a weekly basis. Labeled materials are only effective if applied before populations explode.

Snap Beans
You will need to consider a treatment for corn borer, corn earworm, beet armyworm and soybean loopers. Sprays are needed at the bud and pin stages on processing beans for worm control. With the diversity of worm pests that may be present in fields, be sure to scout fields and select materials that will control the complex of insects present. For the most recent trap catches in your area and to help decide on the spray interval between the pin stage and harvest for ECB control in processing snap beans, you will need to call the Crop Pest Hotline (in state: 800-345-7544; out of state: 302-831-8851) or check our website http://ag.udel.edu/extension/IPM/traps/latestblt.html and http://ag.udel.edu/extension/IPM/thresh/snapbeanecbthresh.html.

Spinach
Both webworms and beet armyworms moths are active at this time and controls need to be applied when worms are small and before they have moved deep into the hearts of the plants. Also, remember that both insects can produce webbing on the plants. Generally, at least 2 applications are needed to achieve control of webworms and beet armyworm.

Sweet Corn
Be sure that a spray is applied as soon as ear shanks are visible on plants (before you see any silk). If fall armyworms are present in the whorl, you will need multiple whorl sprays for this insect before the ear shank spray to achieve effective control and to prevent larvae from dropping into the ear zone. Once fields are silking, you will need to check both blacklight and pheromone trap catches for silk spray schedules since the spray schedules can quickly change: http://ag.udel.edu/extension/IPM/traps/latestblt.html or call the Crop Pest Hotline (in state: 800-345-7544; out of state: 302-831-8851). Be sure to check all labels for days to harvest and maximum amount allowed per acre.