Since my blog entry last week where I mentioned that we hadn’t found WBC feeding in dry beans yet, my crew as well as reps who have been sending photos in have found WBC pod feeding in dry bean fields at a few locations across the province. To date, sites known to have WBC pod feeding include: Talbotville and Dutton (Elgin County), Dublin (Perth County), a few fields in Northern Huron County (nearest towns not known at this time) and Belleville (Hastings County). I am sure that more will be found this week or next.
I recognize that it is a challenge to figure out if it is actually WBC feeding or not. I am finding more European corn borer in beans then expected. But the good thing is that ECB tends to leave a lot of frass just outside of the hole they made to enter the pod and you can sometimes even find them inside the pod. Corn earworm is also doing some of the pod feeding. The important thing to do is to open up pods that have holes going directly into the pod and look for feeding on the seeds. If there is some seed feeding and no culprit present to point the finger at, it COULD be WBC. WBC feed at night in dry beans so you are not likely to ever get a chance to see the WBC larvae.
If you are finding pods with holes in them on more than just a few plants in the field, we do recommend spraying if the crop is less than 21 days to harvest. If it takes you an hour to find just a couple of pods with feeding, then that field is probably safe but scout it again later that week to see if pod feeding has increased. Matador is registered for control. Don’t spray at the heat of the day as temps above 25 degrees can decrease the products efficacy. Days to harvest interval for Matador on dry beans is 21 days and for snaps and green beans it is 7 days to harvest.