Horned Spanworm – Nematocampa resistaria

Horned Spanworm – Nematocampa resistaria Common Name: Horned Spanworm Latin Name: Nematocampa resistaria Appearance: The Horned Spanworm has a wingspan of about 25 mm. The wings are light brown with a dark brown or black pattern. The larvae are green with tiny black dots and two prominent horns on the head and tail. Egg: The eggs are small, yellow, and laid in clusters on the leaves of the host plant. Pupa: The pupa is brown and about 10 mm in length. Larva: The larvae of the Horned Spanworm are green with tiny black dots and two prominent horns on the head and tail. They are about 25 mm in length when fully grown. Adults: The adults have a wingspan of about 25 mm. The wings are light brown with a dark brown or black pattern. Host plant: The Horned Spanworm feeds on various deciduous trees and shrubs, including oak, maple, cherry, and willow. Territory: The Horned Spanworm is found throughout North America. Damages caused by Horned Spanworm: The larvae of the Horned Spanworm feed on the leaves of the host plant, causing defoliation. Heavy infestations can lead to stunted growth, reduced vigor, and even plant death. Life history and Habits: The Horned Spanworm undergoes complete metamorphosis, with four life stages: egg, larva, pupa, and adult. The eggs are laid on the leaves of the host plant, and the larvae hatch and begin feeding on the foliage. The larvae feed for several weeks before pupating in a cocoon. After pupation, the adult moths emerge and mate, starting the cycle again. The Horned Spanworm has one generation per year, and the adult moths are active from late spring to early summer. They are primarily active at night and can be attracted to light.