Large areas of kernels may be consumed. If you are not using the speed-scout tool, check 20 plants in at least five areas of each field. Peak moth activity in the High Plains region usually occurs from mid to late July. Farmers then monitor their crops for egg masses and spray once a certain threshold is reached. The western bean cutworm is a late-season pest and its feeding can cause both yield loss and degrade quality of grain. The free app can be downloaded from the Apple App Store or Google Play by searching "western bean cutworm. Mature larva feeding near the ear tip.
Western bean cutworm
Traps should stay up until no moths are caught for at least two consecutive weeks. Insecticide timing is critical. Abstract The western bean cutworm, Striacosta albicosta Smith Lepidoptera: Damage in most fields did not reach economic levels. The rapid eastward expansion of the western bean cutworm has prompted the development of resources for identification, scouting, and integrated pest management IPM recommendations for much of the Corn Belt where this pest previously did not occur. This expansion has led to a resurgence of interest in this pest, particularly in areas where it has most recently caused damage.
WESTERN BEAN CUTWORM: TIME TO SCOUT | KNEB
Injury to Corn Western bean cutworm caterpillars can be observed feeding on leaf tissue, silks, and tassels but this type of feeding rarely cause significant injury to corn, unless populations are very large. Description Young larvae are dark brown and are easily identified by a faint diamond marking on their backs. Economic Importance Historically, the western bean cutworm was a pest on corn and dry beans in the western cornbelt. If corn has not tasseled, larvae feed on pollen in the developing tassel within the flag leaf. Eggs soon turn tan and pink as they develop, and will turn purple 1 to 2 days before hatching Figure 3. One larva per plant usually does not cause severe damage to the ear. If it is red, the count has increased from the previous week.
Corn can experience severe damage when multiple larvae are feeding within an ear. Western bean cutworm egg mass Western bean cutworm larvae have stripes on the prothorax. Newly hatched larvae are pale with light-brown stripes running lengthwise down the back. Mature larvae enter the soil and construct the overwintering cells for the prepupal stage. Bt corn hybrids with Herculex I and Herculex XTRA Containing the event TC with Cry1F are said to provide adequate protection against larvae of the western bean cutworm and may be a consideration for producers who have experienced problems with this pest.