Month: May 2017

Cutworms – Numerous cutworms are active. Perhaps the first to show its feeding is the Eastern Black Cutworm often confused with the dingy cutworm.  Dr. Tooker has a tracking network and moth fights were heavy in some areas in Lebanon area the sites were high in trap counts while other areas were low in numbers this indicates that the cutworms could be a problem in some fields and not others.  As of today in Lebanon we had a peak flight of May 3 perhaps a week earlier.  From May 3 to today May 22 we had 200 heat units.  This would indicate we should be seeing some leaf feeding and in some fields cutting of plants.  There are more of these cutworms that  we will begin to see.  The true armyworm and then European corn borer will become active. For this article a focus will be on Eastern Black Cutworm. The damage is from chewing mouth parts and this picture illustrates damage caused by cutworms. Often times when larvae are large they will completely cut the plant off at ground level.

Management

·         T band insecticide at planting where numerous options are available.

·          If larvae are less than 1 inch long.
Cutworms longer than one inch are likely to pupate (i.e. cease feeding) before causing significant additional damage.

·         The selection of Herculex 1 Bt hybrid( you will find feeding damage however in most cases cutting is suppressed and you will find larvae after they feed will be dead or dying.

·         Neonicotinoid(Poncho, Cruzer) seed treatments at high level rates will also suppress the pest from reaching large enough size to cut.  Scouting is important to ensure the treatment is working.

·         Curative treatments – if threshold levels of cutting damage are noted then treatments are necessary.