Montana Field Guide

The following is taken from Wallis (1961), Acorn (2001), Pearson et al (2015). The body length is 12-13 mm. Dark brown to purple above. Maculations are heavy, and complete. Middle maculation is perpendicular or nearly so to margin before turning posterior at a right angle, often with a slight anterior bump at the bend. The shoulder (humeral) maculation is coat-hook or G-shaped (left) or inverted G-shape (right). There is a distinctive tuft of long white hairs (setae) on the side of the thorax. Below, purple to blue-green on the abdomen, sides of thorax coppery. Body, legs, forehead hairy, labrum medium, mandible with 1 tooth.

Tiger beetle life cycles fit two general categories based on adult activity periods. “Spring-fall” beetles emerge as adults in late summer and fall, then overwinter in burrows before emerging again in spring when mature and ready to mate and lay eggs. The life cycle may take 1-4 years. “Summer” beetles emerge as adults in early summer, then mate and lay eggs before dying. The life cycle may take 1-2 years, possibly longer depending on latitude and elevation (Kippenhan 1994, Knisley and Schultz 1997, Leonard and Bell 1999, Pearson et al. 2015). Adult Cicindela hirticollis couleensis a spring-fall species found May-June and August-September (Larochelle and Larivière 2001). Not described for Montana but probably similar to Idaho (see comments in Sauder 2017).

The following comes largely from Pearson et al. (2015). Most similar in appearance to the Bronze Tiger Beetle (Cicindela repanda), which has a shoulder (humeral) maculation that is elongate C-shaped not G-shaped. Also the long dense tufts of hairs (setae) on the side of the thorax are absent or less obvious in C. repanda. Differs from C. h. shelfordi (the other subspecies in Montana) primarily by range, being west of the continental divide in the Columbia River drainage (not in the eastern prairies), and dorsal coloration, maculations, and size. C. h. shelfordi is reddish-brown, not dark brown to purple, the maculations are connected along elytra margins, and is slightly larger than C. h. couleensis. Subspecies validity is questionable, based on recent range-wide mDNA analysis, although western forms showed some differentiation (Pearson et al. 2015).

Non-migratory but capable of dispersal. When wings are fully developed (macropterous), it is a strong flier, and fast runner (Larochelle and Larivière 2001).

Adult and larval tiger beetle habitat is essentially identical, the larvae live in soil burrows (Knisley and Schultz 1997). Across the range Cicindela hirticollis couleensis is found in open ground associated with sandy banks of rivers, streams and creeks, sand bars, other river sand deposits (Larochelle and Larivière 2001, and Pearson et al. 2015). In Montana, habitat is not described but probably similar to elsewhere across the range.

Larval and adult tiger beetles are predaceous. In general, both feed considerably on ants (Wallis 1961, and Knisley and Schultz 1997). Diet of adult Cicindela hirticollis couleensis not described (Larochelle and Larivière 2001) but probably includes various small insects, spiders, and other small invertebrates.

Larval tiger beetles live in burrows and molt through three instars to pupation, which also occurs in the larval burrow. Adults make shallow burrows in soil for overnight protection, deeper burrows for overwintering. Adults are sensitive to heat and light and are most active during sunny conditions. Excessive heat during midday on sunny days drives adults to seek shelter among vegetation or in burrows (Wallis 1961, Knisley and Schultz 1997, and Pearson et al. 2015). Cicindela hirticollis couleensis has a narrow range (stenotopic) of ecological tolerance, being largely restricted to open sandy habitats along rivers (Larochelle and Larivière 2001). Adults are diurnal and gregarious (Larochelle and Larivière 2001). Predators of adults are not described but probably include birds and robber flies (asilids); larvae probably attacked by bee flies (bombyliids) and tiphiid wasps. Associated tiger beetle species include C. columbica, C. oregona, C. repanda, and C. tranquebarica (Sauder 2017).

Life cycle of Cicindela hirticollis couleensis 2 years. Details largely lacking but probably similar to other inland northwest subspecies. Mate in July. Females oviposit in level moist sandy areas. Larval burrows are straight, second-instar burrows are 13.5 cm deep in fine sand. They overwinter as third-instar larvae, reemerge in spring then pupate in early summer. Sexually immature adults (fresh tenerals) emerge in August then overwinter before reemerging the following spring to mate (Vaurie 1950, Larochelle and Larivière 2001, and Pearson et al. 2015). No information on reproductive characteristics for Montana.

Not considered rare or in need of special conservation management (Knisley et al. 2014). However, Cicindela hirticollis couleensis and is currently considered Vulnerable (T3) by NatureServe and is especially sensitive to altered river and stream flows through damming and channelization, and perhaps human disturbance (Pearson et al. 2015). Early-succession sandy habitats near water favored by this species experience vegetation encroachment and stabilization as succession proceeds for whatever reason (Shelford 1907, and Knisley 1979), and benefit from disturbance that retains a mosaic of successional conditions. Some colonies (particularly the larval burrows) could be impacted by trampling through livestock overgrazing or access to water sources at streams and rivers, but grazing at appropriate times and stocking levels could also be beneficial by keeping vegetation cover more open. Creation of dredge spoils from channelization could benefit this species (Knisley 2011). Retention and restoration of natural stream and river sediment-deposition processes (especially of sand, not silt) will also benefit this species, as will controlled burns to reduce vegetation cover and encroachment.