Damage
Leaves curled, webs present

Possible Causes
Webworms; obliquebanded leafrollers

Damage
Leaves with numerous, small holes

Possible Causes
Adult flea beetles; plant diseases

Damage
Leaves spotted 

Possible Causes
Tarnished plant bugs; spider mites;
thrips; lace bugs; plant diseases

Damage
Leaves or stems speckled or silvery

Possible Causes
Thrips

Damage
Leaves and stems with hardened
bumps, scales, or cottony growths

Possible Causes
Scales; mealybugs; plant diseases

Damage
Leaves with shallow tunnels under
leaf surface.

Possible Causes
Larval leafminers; sawflies

Damage
Leaves with shiny, slimy, frothy, or 
sticky coating

Possible Causes 
Aphids; mealybugs; slugs and snails;
pear psyllas; scales; spittlebug; whiteflies;
plant diseases

Damage 
Fruit with tunnels throughout

Possible Causes
Apple maggots; moth larvae like codling moths 
or European corn borers

Damage
Fruit distorted, twisted

Possible Causes
European corn borers; tarnished plant bugs

Damage
Fruit spotted, sticky

Possible Causes 
Aphids; leafhoppers; spittlebugs; plant diseases

Damage
Rootsor bulbs with signs of feeding or dead spots

Possible Causes
Wireworms; many kinds of beetle grubs; weevils 
(black vine, carrot, or strawberryroot weevils)

Damage 
Roots or stems with galls, swellings

Possible Causes
Gall wasps; nematodes; plant diseases

Damage
Roots or stemswith excessive branching

Possible Causes
Nematodes

Damage
Stems hollowed, with larvae inside and leaves wilted

Possible Causes
Borers (European corn, flatheaded appletree, fruit, peachtree,
roundheaded appletree, and squash vine borers)

Damage
Flowers eaten

Possible Causes
Japanese beetles; rose chafers

Damage
Flowers fall before opening

Possible Causes
Tarnished plant bugs

Damage
Seedlings chewed off at soil level

Possible Causes
Cutworms; animal pests