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Major Types of Invertebrate Pests and their Damage

On this page
  • Caterpillars
  • Mites
  • Thrips
  • Other leaf-chewing invertebrates
  • Avocado lace bug
  • Plant sap-sucking insects

When to monitor:

  • Avocado thrips in February or March, then regularly from April until fruit exceed 3/4 inch.
  • Caterpillars from March through August.
  • Greenhouse thrips from late-March through July.
  • Persea mite and sixspotted mite from April through October.

Names link to more information on identification.

Click on photos to enlarge

Young avocado fruit damaged by omnivorous looper
Identification tip: Leaf edges chewed. Foliage may be webbed or tied together with silk. Fruit injury varies from oval craters to scattered gouges in the skin.

Leaves with necrotic spots and silky webbed patches caused by persea mites
Persea mites
Identification tip: Leaves bleached, bronzed, spotted, or stippled. There may be pale silken patches, but no black excrement, on underside of leaves.

Avocado fruit scarred by avocado thrips
Identification tip: Fruit with brown scars, leaves with pale stippled, bleaching, or black excrement on plants. Damage and signs vary depending on the species of tiny, slender thrips.

Chewed leaves
Other leaf-chewing invertebrates
Identification tip: Notched, chewed, or missing foliage not  caused by caterpillars. Beetles, earwigs, grasshoppers, and snails are relatively uncommon or are a concern only on young trees.


Feeding damage of avocado lace bug
Avocado lace bug
Identification tip: Leaves bleached or stippled (resembling mite feeding) and brown dead leaf blotches. Black excrement on underside of leaves from sap-sucking bugs.

Sticky honeydew from sap-sucking insects
Plant sap-sucking insects
Identification tip: Sticky honeydew, blackish sooty mold, whitish wax, or trails of pest-tending ants. Infestations of mealybugs, scale insects, and whiteflies indicate that biological control has been disrupted as these Homoptera are especially well controlled by parasites and predators.

Statewide IPM Program, Agriculture and Natural Resources, University of California
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Agriculture and Natural Resources, University of California

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