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Spiny elm caterpillar

Nymphalis antiopa

23 host plants

Last updated

Data Coverage 1 of 6 dimensions
Host Plants
GDD Threshold
Peak Activity
Damage Severity
Monitoring
Regional Notes

Purplish-black caterpillars with white specks, orange to red spots along the back, and long forked spines reach about 2 inches when mature on elm, willow, hackberry, and cottonwood. These spiny caterpillars feed in large groups and eat all leaves on a branch before moving; their presence is signified by defoliation of entire branches.

Well-established trees tolerate defoliation without serious injury. These caterpillars rarely warrant control measures. Prune defoliated branches if important for appearance. Spines do not cause serious human health impacts. Natural parasitic wasps usually maintain low populations.

Quick Reference

Order
Lepidoptera
Type
defoliator
Host Plants
23

Cultural Controls

  • Hand-pick caterpillars when practical.
  • Numerous parasites and predators, including parasitic wasps and some birds, help keep spiny elm caterpillar populations in check.

Host Plants (23)