Pest profile

European Apple Sawfly

Hoplocampa testudinea · Hymenoptera: Tenthredinidae[3]

European apple sawfly larvae scar young apples with winding, ribbon-like trails, then bore into the seed cavity and make the fruit drop.[1][2]

Red apple with a curving, ribbon-like scar left by a young European apple sawfly larva
Red apple with a curving, ribbon-like scar left by a young European apple sawfly larva. (c) ingridaltmann, some rights reserved (CC BY) — via iNaturalist, CC BY 4.0

How to identify it

  • Adults are wasp-like insects about 5/16 inch long, but with a broad join between thorax and abdomen.[1]
  • Larvae look like caterpillars but have prolegs on every abdominal segment.[1]
  • Older larvae leave entry holes with brownish frass on the fruit.[2]

Look-alikes

Look-alikeHow to tell them apart
Caterpillars in applesSawfly larvae resemble caterpillars but have prolegs on each abdominal segment.[1]

Where it lives

Penn State Extension covers it in Pennsylvania apple orchards and home fruit plantings.[1][2]

Biology and life cycle

There's one generation a year, and larvae overwinter in the soil.[1]

Adults emerge during late pink and early bloom and lay eggs on the calyx end of developing fruit.[1]

Young larvae tunnel just under the skin; second and later instars bore into the seed chamber and can move on to other fruit.[2]

Damage and signs

  • Early feeding leaves a winding, ribbon-like scar; these apples usually stay on the tree, and the scars lower their value.[1][2]
  • Older larvae bore deep into one or more fruits, usually making them drop in mid-season.[1]

Health risk

It feeds on plants; Penn State Extension mentions no risk to people.[1]

Control

Prevention

Orchards hang white sticky traps on the south sides of trees, 5 to 6 feet up, at the pink stage to track adults.[2]

Biological control

No native natural enemy is reported to be effective in North America; Canada introduced the parasitic wasp Lathrolestes ensator with partial success.[2]

Pesticides

Where this sawfly has been a problem before, Penn State's best tactic is a spray as soon as pollination is complete.[1][2]

Common questions

What makes a curving ribbon scar on an apple?
A young European apple sawfly larva tunneling just under the skin.[2]
Why are young apples with holes dropping mid-season?
European apple sawfly is one cause; older larvae bore into young fruit and usually make it drop.[1]

Sources

  1. Penn State Extension, “European Apple Sawfly in the Home Fruit Planting.” extension.psu.edu/european-apple-sawfly-in-the-home-fruit-planting (accessed 2026-10-06)
  2. Penn State Extension, “Tree Fruit Insect Pest: European Apple Sawfly.” extension.psu.edu/tree-fruit-insect-pest-european-apple-sawfly (accessed 2026-10-06)
  3. iNaturalist, “Hoplocampa testudinea taxon page (order and family).” www.inaturalist.org/taxa/483616 (accessed 2026-10-06)

Updated 2026-10-14. Built from sourced records. Spot an error? Tell us.