Xtremehorticulture

Not Thrips on Grapes. Leafhoppers!

Q. Some kind of thrip-like
bug has invaded my garden. My grapes leaves are brown and drying up from these
bugs. There’s tiny black spots where they were. There’s so many of them I can
hear them as I approach the plant. I applied Spinosad in September but it
didn’t do anything. Now they’ve gotten into my peach tree.


A. The tiny black spots on
grape leaves is fecal matter (poop) from leafhoppers, not thrips. Thrips are very
common on grapes here that feed on plant juices from the leaves of grapes and
other plants.
            Leafhoppers start building their colonies in grapes
around April. Once established, they will build huge colonies in the grapes and
spread to other plants.

grape leafhopper damage

            They are easy to get under control in April and May when
they are young. They are extremely difficult to control without some heavy duty
insecticides later in the season.
            Spinosad, a natural insecticide spray, works great if
applied early in the season such as April and May. Later in the season you will
need to bring out some heavy duty artillery to get them under control.

Leafhoppers greatly magnified. They are maybe 1/8 inch long

            I hate to recommend anything this late in the year
because the insecticides needed are very heavy-duty. It is best if you can wait
until next spring and begin treatment early with Spinosad or pyrethrin sprays.
Spinosad active ingredient

            Alternate Spinosad with insecticidal soap and neem oil.
Make sure to spray the tops and bottoms of the leaves. If using Spinosad, two
sprays about six weeks apart starting in late April will take care of them, the
hornworms and the skeletonizers all at the same time.

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