Raspberry: Loopers

categories: Raspberry Raspberry Insects Small Fruits

last review date: 2025-11-13 03:57

Biology

Loopers are green caterpillar up to about 1 1⁄2″ in length. They may have pale or dark stripes along the body. They are distinguished by their characteristic looping or “measuring-worm” movement.

Loopers feed on leaves of many plants, chewing holes in the leaves or feeding along leaf margins. The adult of the alfalfa looper, a species common on raspberry, is a mottled brown moth with silver markings.

Wingspan is approximately 1 1⁄2″. The primary damage caused by loopers is the contamination of harvested fruit.

Management Options

See "Using Integrated Pest Management (IPM) in the Landscape" for successful problem management techniques.

Non-chemical Management

Select non-chemical management options as your first choice!

• Hand-pick and destroy any caterpillars or cocoons found on leaves.
• Natural enemies of caterpillars include predacious beetles, parasitic wasps, and birds. Avoid use of broad-spectrum insecticides when possible to conserve beneficial insects.

Chemical Management

IMPORTANT: Visit Home and Garden Fact Sheets for more information on using pesticides.

• Apply to control loopers when first noticed.
• Use a spreader-sticker with liquid Bt formulations.

Approved Pesticides

Examples of pesticides that are legal for home use in Washington State are listed below.
The list may not include all products registered for this use.

• Bonide Captain Jack's Deadbug Brew R-T-U [Organic]
  Active ingredient: spinosad (spinosyn A+D) (EPA reg. 4-472)
• Bonide Thuricide BT Concentrate
  Active ingredient: Bacillus thuringiensis subsp. kurstaki (EPA reg. 4-226)