Purplestriped shootworm

Distribution

Quebec, Nova Scotia, Ontario, British Columbia, Yukon, Newfoundland and Labrador

This species occurs throughout the interior of British Columbia; it also occurs north to the Yukon and east to Nova Scotia.

Micro-habitat(s)

Annual shoot, Needle

Damage, symptoms and biology

Zeiraphera unfortunana is a common pest of spruce sometimes causing visible damage to expanding new terminal shoots.

Mature larva up to 15 mm long. Head, chestnut brown to dark brown. Thoracic shield dark brown. Body, creamy yellow with broad reddish brown dorsal and lateral stripes; two pairs of prominent dark dorsal spots (pinnacula) on the dorsum of each abdominal segment.

This species overwinters in the egg stage. Larval emergence begins in late May, coinciding with the opening of the new buds. Larvae are present from June to early July. Once the larvae are mature, they drop to the ground where they pupate. Pupation lasts up to 3 weeks. Adults emerge from July to early August.

Main host(s)

Balsam fir, Engelmann spruce, subalpine fir, white spruce

Secondary host(s)

Black spruce, Douglas-fir, False Cypress, Cedars, Cypress, Norway spruce, red spruce, Sitka spruce, spruces, trembling aspen, white spruce