Lesser Cornstalk Borers (LCB) is one of the most damaging insects to peanuts. LCB is a caterpillar pest that bores into peanut stems, crowns, and pods. Feeding can reduce yield and directly increase the risk of aflatoxin. Right before this little period of rain showers that we are currently experiencing LCB populations were starting to increase. LCB love it when it’s hot and dry which is the way it has been in the previous weeks. If wet weather continues for an extended period of time LCB populations should decline. If the hot and dry returns you better be scouting for them because an outbreak could occur. If your peanuts are irrigated, that does not mean that you should stop scouting for LCB especially if the vines haven’t lapped yet. Once the vines lap in an irrigated field your chances of LCB outbreak are reduced. There are no “preventative” sprays for LCB. Scouting is your best tool. Below I have pictures of LCB caterpiller, LCB silk tubes, and LCB moth.
Treatment:
- Prevathon at 16 fl. oz/acre OR Diamond at 6-9 fl. oz/acre
- Besiege at 10 fl. oz/acre BUT only use Besiege in irrigated peanuts. Besiege contains a pyrethroid and pyrethroids flare spider mites. So Besiege is not recommended for dryland fields.
- Do not use Dimilin
Lesser Cornstalk Borer found boring into peanut plant
Look for silk tubes when scouting for Lesser Cornstalk Borer
Lesser Cornstalk Borer Moth