White slaut

Scientific name: Tetracis cachexiata (Guenée)
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Lepidoptera
Family: Geometridae

Distribution

British Columbia
Ontario
Quebec

This species is generally distributed throughout the southern interior of British Columbia; it also occurs east to Nova Scotia and south to Florida.

Damage, symptoms and biology

Tetracis cachexiata is a relatively uncommon innocuous solitary defoliator.

Mature larva up to 45 mm long. Head, small, flattened, dull yellowish white with dark markings. Body, brown to grey and variously marked with repeating middorsal hourglass pattern. Body slim, wider from segments 6-9. Second thoracic segment with a pair of large angular lateral swellings and small addorsal tubercles. Both abdominal segments 4 and 5 have a pair of subdorsal tubercles.

Larvae are present from early June to late September. Pupation occurs from July to mid-August, and adults emerge in September or May.

Canadian Forest Service Publications

White slaut

Diet and feeding behaviour

Phyllophagous: Feeds on the leaves of plants.
- Free-living defoliator: Feeds on and moves about freely on foliage.

Information on host(s)

Coniferous hosts of Tetracis cachexiata primarily include Douglas-fir, tamarack and white spruce; other hosts include white birch, trembling aspen and willow.