Q.
My grapevine has been overtaken by these worms/insects and at least 25% or more
of the leaves have been eaten and/or turning brown. Are the grapes safe to
eat? I've attached some pics. Early in the season I was spraying the vine
with BT but maybe I didn't apply it often enough? Could the netting that I put over the vines
have made it easier for them to multiply like they did? I know it made it difficult for me to get to
the undersides of a lot of the leaves, but it was that or feed the birds! I think I will forgo the netting going
forward now that the grapevine is more established.
 |
| Midseason attack of grape leaves by grape leaf skeletonizer larva |
A.
I don’t think the netting had anything to do with skeletonizer. The only thing
I can think of is that birds might not have been able to get in to get the
adult moths. They will not touch the larvae as they have stinging hairs near
their heads which keep birds from eating them.
There
are probably five generations of these larvae in one season and they probably
overlap on each other. The first one starts about April/Mayish and a new
generation every 4 to 6 weeks so if you don’t spray at least three during the
season you will miss a generation or two.
The
Bt spray only lasts a few days and it is gone. Control = picking the right
poison, applying at the right time, at the right dosage and the right coverage. You probably missed one or more of the generations.
Start spray applications in May. Apply every two months during warm weather. Read and follow the
directions on the label. Use a “sticker” such as EZ Wet or equivalent, Apply to
both the top and bottom of the leaves.
The
grapes are safe to eat. Just make sure you wash them.The netting is more for bird control than anything else. It is wise to delay putting bird netting over the top of grape vines until you start to see the berries turning color.
