Do Japanese beetles affect the grapes?
YES, they sure do. I thought this would be an appropriate question for July since the first of the Japanese beetles arrived in our vineyards this week. In many years we can ignore them because their populations are small and they only do a little damage to the vines. The last two years, however, have been absolutely horrible with regards to the beetles and it looks like 2008 may be another bad year. How much damage can they do you may ask. Well, if we don’t kill them, they can completely strip a vine of leaves. Without leaves, photosynthesis cannot occur and the vine cannot ripen the grapes. Unfortunately, nobody has found a natural solution on a commercial scale that has been very effective on the beetles and we need to spray insecticide when the populations get too high. There are so many beetles that after spraying, you can walk on a crunchy carpet of dead beetles in the vineyard which is quite disgusting!
