Q: We have a thornless blackberry vine. The fruit has been ripening well up until the last day or so. Several of the drupeletes on particular fruits have all of a sudden begun to turn white.
A: It’s both sunscald and possible feeding damage by stinkbugs or leaf-footed bugs. Sun-scalded fruit has white drupelets on the side facing the sun. Stinkbug injury is shown by scattered individual drupelets turning white, some of which may show feeding damage.
Stinkbugs are brown or green and shield-shaped. Leaf-footed bugs have a leaf-shaped appendage on their legs. Stinkbugs are easy to see and have a pungent, fetid smell when alarmed.
In my view, there is no harm in eating fruit after one has visited: I’ve tasted lots of blackberry fruit that was tainted by their smell.
Any labeled garden insecticide will kill bugs but read and follow the label directions about washing the fruit before eating.
For organic control, try spinosad ( Captain Jacks Dead Bug Brew, etc)