narrow-collared snail-eating beetle

Scaphinotus angusticollis    Family: Carabidaea

Common name: narrow-collared snail-eating beetle; 
narrow-collar snail-eating beetle

Food: snails; slugs; earthworms; spiders; insects; berries
Adult size: 1.5 – 2 inches (4-5 cm)

Type: Beneficial

Life cycle phases: 
                  Generation: 1 over a year and a half
                  Egg: laid in May – June
                  Larva: about 1 year
                  Pupa: about 2 months
                  Adult: 4 – 5 months

Description & Life cycle:
Entire beetle is black. Almond-shaped abdomen has an overlaying rosy-purple matte luster. The pronotum is rather heart-shaped and ridged on both sides. Head and prothorax are long and narrow. Underlip is deeply notched. Antennae are long and slender with 5th segment and beyond covered with short hairs. Long legs raise the body up from the ground.

Eggs are laid under debris in May through June. After hatching, larvae actively feed on slug and snail eggs, as well as earthworms and other insects. Larvae overwinter in soil. Pupation occurs when soil warms up in spring. Adults appear in June and are active through into September, largely at night.

Special Notes:
This is a nocturnal beetle native to southern regions of British Columbia to northern portion of California, mostly west of the BC Coast Range mountains and the Cascades but also on the eastern slopes of the foothills. There is a black form found almost exclusively on Vancouver Island. Preferred habitat is moist forest areas, usually under logs and other debris. Feeds on slugs, snails, earthworms, spiders, earth-dwelling insects and berries. Narrow head and prothorax allow this beetle to reach inside the curved shell of a snail to pull it out.

Remedial Action:
None. This beneficial insect is to be encouraged into our gardens.


Posted on August 12, 2020