Spruce Needleminer

How to identify it

• Look for clumps of brown needles held together by webbing that can easily be pulled apart.^[1][2]
• Mined needles have a small exit hole at the base, where the caterpillar entered or left.^[2][1]

Where it lives

It attacks most kinds of spruce; Illinois and Iowa State Extension both report it.^[1][2]

Biology and life cycle

Eggs are laid overlapping like shingles on spruce needles; the young caterpillar enters the base of a needle and hollows it out.^[1]

Caterpillars feed on one needle after another until fall, overwinter inside a needle, then resume feeding in spring until they pupate.^[1]

Damage and signs

• Damage is typically more unsightly than fatal.^[2]

Health risk

None to people or pets.^[1][2]

Control

Traps and physical control

On small trees, wash the webbed needle debris out with a forceful stream of water from a hose, or prune off and destroy infested stems where practical.^[2]

Pesticides

If spraying, apply a contact insecticide labeled for spruce in early spring while the caterpillars are active (until about mid May, according to Iowa State).^[1][2]

Common questions

Why are there clumps of webbed brown needles on my spruce?

Spruce needleminer caterpillars mine needles, cut them off and web them together.^[1][2]

Will spruce needleminer kill my tree?

Damage is typically more unsightly than fatal.^[2]

When should I spray for spruce needleminer?

In early spring, while the caterpillars are active.^[1][2]

Sources

1. University of Illinois Extension, “Spruce Needle Miners.” extension.illinois.edu/insects/spruce-needle-miners (accessed 2026-10-15)
2. Iowa State University Extension and Outreach (Yard and Garden), “Spruce Needleminer (May 20, 2009).” yardandgarden.extension.iastate.edu/article/2009/5-20/needleminer.html (accessed 2026-10-15)
3. iNaturalist, “Endothenia albolineana taxon page (order and family).” www.inaturalist.org/taxa/1020995 (accessed 2026-10-06)