Buds and Shoot Insects
FIELD GUIDE TO INSECTS AND DISEASES OF ARIZONA AND NEW MEXICO FORESTS

Pinyon and Ponderosa Pitch Nodule Moth
Retina (= Petrova) arizonensis (Heinrich)
R. metallica (Busck)

Host:  Piñon

Figure 163. Figure 163. Damage caused by the piñon pitch nodule moth.

Symptoms/Signs:  Attacks are characterized by fading branch tips and small nodules of pitch formed at the insects feeding sites. The pitch nodules are hollow balls of pitch 13 to 25 mm long, round, smooth, and light purple to red in color. Pitch nodules usually occur at the crotch of two or more twigs.

Figure 164. Figure 164. Cocoon of ponderosa pitch nodule moth.

Biology:  Small, rusty-brown moths emerge through holes in the pitch nodule in late June and early July. Eggs are laid on the needle sheaths of the current year’s foliage. Newly hatched larvae feed on the young needles before boring into the bark at nodes or whorls of twigs or branches. Full-grown larvae are about 13 mm long, reddish-yellow in color with a black head and a dark area behind the head. Pupation occurs inside the pitch nodule in June. The pupae move just below the pitch surface before they emerge as adults.

Effects:  Attacked twigs and branches are killed. Leaders are occasionally damaged and forked trees may result.

References:  9, 24