Cutworms Can Cause Early Problems In Tobacco Fields

   While serious black cutworm infestations in tobacco fields are not common, they occasionally can strike hard. The potential is greatest in conventionally-tilled fields where winter annual weed growth was evident for several weeks prior to final field preparation and a significant number of cutworm moths have been flying. Degree-day accumulations and moth captures indicate that the first black cutworms should be reaching the cutting stage during the first week of May in southern and western Kentucky. Moths have been flying since the second week of March and are still active so cutworm damage can be expected over the next 3 to 4 weeks.
   Dense low-growing weeds are selected by female moths as ideal places to lay a few eggs. These plants will serve as food for the developing cutworm larvae. When the weeds are killed or turned under, the cutworms suddenly are left without food. Newly-set transplants fill this void and the cutworm larvae quickly resume feeding.
   Cutworms are already present in infested fields before transplanting but there is not a good way to determine whether or not they are present or how abundant they may be. The extent of weed flush in the field over the last few weeks is the best indicator, along with reports of cutworm are in nearby communities from fields that have already been set.
   Capture and Orthene are labeled for cutworm control as transplant water applications. With this approach, the treated area is immediately around the plant roots. Control may not be considered satisfactory if there is a large number of cutworms in the field or if they are large (> 1.5 inches). Lorsban and Capture may be used as pre-transplant soil applications, as an alternative to the transplant water use. Capture, Orthene, or Warrior can be used as broadcast rescue treatments if cutworms are found transplants in the field.
   Cutworms feed at night or on overcast days and hide in the soil during the day. If soil is moist, they may feed on leaves in contact with the ground. In dry soil, they are more apt to stay below the surface and feed on stems, cutting off plants. The first signs infestations can be feeding holes at the leaf edge or cut, wilted plants. Δ
DR. LEE TOWNSEND: Extension Entomologist, University of Kentucky