What's eating my thompson seedless grape?

Thompson Seedless is a primary target for leafhoppers, grape mealybug, and western grape leafroller in California and warm-climate gardens. Birds attack ripe clusters heavily. Powdery mildew-stressed vines become more vulnerable to leafhoppers. Mealybug is the most damaging pest in vineyards, transmitting grapevine leafroll virus.

Cottony white masses under bark and in bunches; honeydew promotes sooty mould and black fruit; transmits grapevine leafroll-associated viruses Apply dormant oil sprays in late winter; encourage lacewings and Anagyrus parasitoid wasps; remove loose bark where females overwinter; use systemic insecticides only as a last resort

Stippled, pale-white leaves; heavy populations cause bronzing and early drop; adult leafhoppers fly up explosively when disturbed Insecticidal soap or pyrethrin applied to leaf undersides; maintain vine canopy for good air circulation; natural parasite Anagrus epos is highly effective where present

Ripe berries eaten or punctured in clusters; secondary fungal rots follow bird damage; worst in the two weeks around harvest Enclose maturing clusters in perforated paper bags; drape bird netting at veraison; harvest promptly

Bronzed, dusty-looking leaves; reduced photosynthesis weakens shoots; hot, dry summers trigger population explosions Predatory mites (Galendromus occidentalis) provide excellent biological control; avoid broad-spectrum insecticides that kill predators; forceful water jets early in the season