Which pest defoliates larches by feeding on needles and then eats all needles the following spring, and is controlled by a parasitic wasp introduced in the 1970s?

• A. Larch case bearer
• B. Cypress tip moth
• C. Pine engraver beetle
• D. Western spruce budworm

Answer: (A)

Larch casebearer is the pest described. This small moth’s larvae feed on larch needles, living in a protective case as they feed, and heavy infestations can strip needles from the tree. The pattern of damage often spans two seasons, with feeding continuing into the following spring as the larvae complete their development. Management historically used a parasitic wasp introduced in the 1970s to curb larch casebearer populations; the wasp parasitizes the larvae, reducing outbreaks without broad insecticide use. This combination—host-specific defoliation on larches and a biocontrol introduced in the 1970s—fits the description better than the other pests, which affect different hosts or have different life cycles.