Montana Field Guide

[From Acorn 2001; Pearson et al. 2006] Length 10-12 mm. Most populations (except the most northern Canadian populations) characterized by a coalescence of maculations so that the elytra are mainly white with a dark triangle down the midline, except for a few small dark patches. Dorsal coloring on head, thorax, elytral patches reddish brown in the north, greenish in the south; undersides coppery green to metallic purple. Underside and thorax thickly covered in whitish hairlike setae, forehead hairy. Legs dark. C. l. nympha, the subspecies in northern Montana and adjacent regions, generally fits the above description, with a thin dark patch posteriorly and sometimes a tiny dark patch anteriorly on the elytra.

Adults emerge the first half of August to late September, hibernate, reemerge the following spring (April to July); larvae take 2-3 years to mature in most areas (Acorn 2001; Larochelle and Lariviere 2001; Pearson et al. 2006).

Best determined by combination of smaller size, mostly white elytra with few maculations, dark legs, and occurrence in sandy habitat.

Non-migratory. Not a strong flier (Larochelle and Lariviere 2001).

For C. l. nympha: sand dunes, sand hills, blowouts, roadsides, roadcuts, sandy lake shores; open ground, well-drained, bare or sparsely vegetated soil (Hooper 1969; Acorn 2001; Larochelle and Lariviere 2001; Pearson et al. 2006).

Larvae and adults carnivorous; the larvae sit-and-wait predators in burrows, the adults actively pursue prey on the ground surface (Acorn 2001; Pearson et al. 2006).

Mating June to July, copulating pairs often seen partially buried in sand. Larvae live in burrows 17.5-42.5 cm deep for about 2 years, inactive in summer and overwinter as larvae (as well as adults), pupate in August and September, emerge as adults in August and September, adult lifespan 1 year (Larochelle and Lariviere 2001; Pearson et al. 2006).