True Armyworm and Black Cutworm Trap Report

David Owens, Extension Entomologist,

Armyworm flight is low in most locations except our trap near Smyrna. Be advised we do not know how counts will correlate to actual pressure in the field. Also of note, black cutworm in Kent and New Castle are very active. This would constitute a ‘significant flight’ meaning that it is time to start looking at degree days. Eggs will hatch about 90 degree days from now or in about 5-10 days, at around 300 degree days, larvae will be large enough to cut plants. Before then, early injury will look like a row of small holes in the leaves. Scout fields once a week for 3-4 weeks after corn emergence.


Moths fly to weedy sections of fields (particularly with chickweed, shepherds purse, peppergrass, brassicas) or fields with a still-green small grain cover crop to oviposit. Please also note that these cutting degree days are most applicable to corn, they may be able to do more damage to soybean earlier. Bt corn varieties with Cry1F or Vip3A traits provide suppression of cutworm.

Many thanks to Maryland extension agents Emily Zobel and Maegan Perdue and UD extension entomologist emeritus Joanne Whalen.

Location Number of Nights Total Catch TAW Total Catch BCW
Willards, MD 7 4 20
Salisbury, MD 7 0 8
Laurel, DE 7 5 21
Seaford, DE 7 2 15
Sudlersville, MD 7 11 6
Harrington, DE 7 14 31
Smyrna, DE 7 375 36
Middletown, DE 7 56 31