Grape
Symptom Cause  
Grapes appear as small, black dots. Purple to black, sunken lesions may also appear on young shoots and stems
Anthracnose Spot
>
Leaves wrinkled or curled; discolored, stunted, tend to fall off
Aphids
>
Leaves eaten entirely or partially
Armyworms
>
Fruit removed and eaten
Birds
>
Small holes in bark/stems , sawdust visible
Borers
>
Roots, stems and/or crowns develop tumors (galls); outer layer turns brown and corky.
Crown Gall
>
Plants/twigs disappear all or in part
Deer
>
Areas between veins turn yellow, then brown; lower surface of leaves have white, purple or black hairy growth.
Downy Mildew
>
Soft, watery spots appear on stems, leaves or fruit; fuzzy white or gray mold forms.
Gray Mold (Botrytis Blight)
>
Grape skin broken, fruit partially eaten
Hornet
>
Holes in leaves and flowers
Japanese Beetles
>
Foliage yellowed or white mottling, glaze of honeydew; plant weakens
Leafhoppers
>
Holes in flowers; leaves rolled up
Leafrollers
>
Cottony white masses on roots, stems, branches leaves; reduced plant vigor
Mealybugs
>
Mottled, crinkled foliage; brown specks appear on tubers, and plants droop & die
Mosaic Viruses
>
Plant stunted, leaves yellowed, lesions on roots
Nematodes
>
Fan-shaped plaques of white fungal strands between bark and wood of roots and lower trunk; armillaria mellea
Oak Root Fungus
>
Young plant wilt, roots gnawed, plant dies
Pocket Gophers
>
White spots on leaves; eventually entire leaf is covered with a white powdery substance.
Powdery Mildew
>
Young plants disappear all or in part; twigs sliced off and lying on ground
Rabbits
>
Leaves yellow, drop; bumps on leaves and stems; sometimes sticky material on leaves
Scale
>
Black mold on leaves and stems of plant
Sooty Mold
>
Leaves stippled, yellow, dirty; webbing on interior stems of plant
Spider Mites
>
Leaves discolored; black fecal spots
Thrips
>
Grape skin broken, fruit partially eaten
Wasp
>
Weakened plant, leaves yellowed, appears like flying dandruff
Whiteflies
>
Grape skin broken, fruit partially eaten
Yellow Jacket
>