| About 2 months ago, my grape grower friend noticed "holes" in the main trunk of his grapevines. They are about 1/2 the size of a pencil eraser, extend about 1/16" into the trunk, and are about halfway up the trunk. The holes are in straightlines around the trunk. The "holes" fill-in (with sap?) within a day & you can hardly tell that the hole was there in the first place. He has applied pesticide for stem borers, which he had had a problem with before, but this has no effect on this new problem insect. What is this insect & what can be done to prevent it in the future? |
| I am almost positive that the holes are caused by Sap Suckers,a bird that makes such hole in many trees and grape vines. A way to control them is to wrap cheese cloth loosely around the trunk of the vine. If it were borers the holes would not have been in a straight line as you describe, but with the sap sucker the holes are in a straight line. |
