Which pest causes elongated chlorotic patches on foliage, a symptom strongly associated with its feeding activity?

• A. Spruce spider mite
• B. Cypress tip moth
• C. Mountain pine beetle
• D. Pine engraver beetle

Answer: (A)

Feeding by a mite causes tissue to lose chlorophyll, producing yellowish or pale patches on needles. The spruce spider mite specifically feeds on spruce needles, and as it chews away at epidermal cells along the needle surface, the result is elongated chlorotic patches that run along the needle or along small bands of tissue. This pattern—pale, elongated areas on the foliage—is a classic sign of mite feeding and is especially associated with spruce spider mite infestations.

Other pests in the list produce different symptoms: the Cypress tip moth damages growing tips with browning or stunted tips rather than pale patches on the entire needle; mountain pine beetle and pine engraver beetle primarily cause symptoms related to bark and wood damage, such as pitch tubes, frass, or widespread canopy discoloration from tree stress, not the elongated chlorotic patches on individual foliage.