Montana Field Guide

The following is taken from Wallis (1961), Graves and Brzoska (1991), Kippenhan (1994), Knisley and Schultz (1997), Leonard and Bell (1999), Acorn (2001), and Pearson et al (2015). Body length is 8-12 mm; above, head and thorax is dark metallic greenish or bluish to coppery-red and with flattened whitish hair-like setae especially dense on the forehead. Elytra is mostly white (rarely brownish), maculations complete with marginal band and greatly expanded, often outlined in pale brown; sides of elytra are distinctly convex. Below, iridescent greenish-bronze with dense hair-like setae. Legs are light-colored to whitish and unpigmented, labrum is wide, 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, and Leonard and Bell 1999). Adult Cicindela (=Ellipsoptera) lepida, a summer species, active period is March to October across range but mostly June to July (Larochelle and Larivière 2001, and Pearson et al. 2015); April to August in Nebraska (Carter 1989), June to August in Colorado and Alberta (Kippenhan 1994, and Acorn 2001). Poorly described for Montana but probably similar to Alberta.

The following comes largely from Kippenhan (1994), Acorn (2001), and Pearson et al. (2015). Not likely to be confused with any other tiger beetle in Montana, especially in the hand. The combination of dorsal coloration and pattern, extensive elytra maculations, and pale legs, are unique. Most similar in appearance and size, and easily confused at a distance in sandy habitats, with the Sandy Tiger Beetle subspecies (Cicindela limbata nympha) occurring in the northern Great Plains and Canadian prairie provinces. Cicindela limbata nympha has a reddish-brown wedge down the center of the back on the whitish elytra and the legs are dark, not pale.

Non-migratory but capable of dispersal. Sometimes found many kilometers from breeding habitat. When wings are fully developed (macropterous), normally a weak 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 (=Ellipsoptera) lepida is associated with pale loose sand with sparse vegetation, and well-drained open ground: sand dunes, dune fields, blowouts, sand flats, roadside banks, sandy river banks and bars, coastal dunes, sand ridges in open forest. Not necessarily associated with water; adults often on wind-swept dune crests and slopes as opposed to bottoms, larvae in sheltered bowl areas of dunes or slopes of banks exposed to wind (Shelford 1907, Vaurie 1950, Wallis 1961, Hooper 1969, Knisley 1979, 1984, Carter 1989, Graves and Brzoska 1991, Kippenhan 1994, Stanton and Kurczewski 1999, Acorn 2001, Larochelle and Larivière 2001, and Pearson et al. 2015). In Montana, habitat is poorly described but probably similar to elsewhere across range.

Larval and adult tiger beetles are predaceous. In general, both feed considerably on ants (Wallis 1961, and Knisley and Schultz 1997). The diet of adult Cicindela (=Ellipsoptera) lepida in the field includes various insects, and in captivity carabids, house flies, spiders, lean meat. The diet of larvae in captivity includes lean meat (Larochelle and Larivière 2001).

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, and Knisley and Schultz 1997). Cicindela (=Ellipsoptera) lepida has a narrow range of ecological tolerance (stenotopic). Adults are diurnal and nocturnal, often attracted to lights at night, gregarious, becomes active at about 18°C then throughout the day but mostly in morning and at dusk. Basks to elevate body temperature, hides in a burrow (3-6 cm deep) in sand or under grass during hottest parts of day or during cloudy, cool or rainy conditions. Very wary, and very cryptic when motionless, and when pursued, often runs about 2 m through sparse vegetation or flies 2-5 m (Vaurie 1950, Knisley 1979, Kippenhan 1994, Larochelle and Larivière 2001, and Pearson et al. 2015). Predators of adults include the Big Sand Tiger Beetle, Cicindela formosa (Acorn 2001), probably birds, spiders, and robber flies (Asilidae). Emits a faint scent when captured. Adults may sometimes occur at densities exceeding 2 per m2 (Knisley and Schultz 1997, Acorn 2001, and Larochelle and Larivière 2001). Associated tiger beetle species include Cicindela formosa, C. limbata, C. (=Ellipsoptera) marutha, C. (= Cicindelidia) punctulate, C. repanda, and C. scutellaris (Graves and Brzoska 1991, Kippenhan 1994, Knisley and Schultz 1997, Stanton and Kurczewski 1999, Acorn 2001, and Larochelle and Larivière 2001).

The life cycle of Cicindela (=Ellipsoptera) lepida is 2 years. It is a two-brooded species with adults of each brood emerging in alternate years (Leonard and Bell 1999, Larochelle and Larivière 2001, and Pearson et al. 2015); overwintering twice, first as second-instar larvae and again as third-instar larvae, adults emerge in mid-summer, live about 2-3 months while they mate (June to August) and lay eggs; females sometimes mate in adult burrows. Eggs are a yellow-cream color, laid in shallow burrows in pure drifting sand. Larval burrows are vertical with a funnel at the entrance, 60-90 cm deep in the second instar, typically 150-190 cm deep (up to 300 cm) in the third instar. Overwintering burrows are usually greater than 70 cm deep and closed. The duration of larval life is 22 months, pupation in May-July in a lengthy and curved cell off of the main burrow. Fresh adults (tenerals) emerge June-August, reach sexual maturity in 2-3 weeks (Criddle 1907, 1910, Shelford 1908, Vaurie 1950, and Larochelle and Larivière 2001). No information on reproductive characteristics for Montana.

Not considered rare or in need of special conservation management (Knisley et al. 2014). Nevertheless, Cicindela (=Ellipsoptera) lepida is sensitive to anthropogenic disturbance, such as off-road vehicle use (Knisley and Schultz 1997, and Stanton and Kurczewski 1999), has been experiencing local declines, and a conservation assessment has been written for the species for at least one state, Nebraska (Panella 2012). Sandy habitats favored by this species experience vegetation encroachment and stabilization as succession proceeds (Shelford 1907, Catling et al. 2008), and benefit from disturbance that retains a mosaic of successional conditions. Absence in Theodore Roosevelt National Park, North Dakota in early 21st century, near the Montana state line, attributed during recent decades to increased precipitation and vegetation encroachment (as well as increased human activity) on sand dunes (Kritsky and Smith 2005), which probably impacts the range in eastern Montana in a similar way. Some colonies (particularly the larval burrows) could be impacted by trampling through livestock overgrazing, but grazing at appropriate times and stocking levels could also be beneficial by keeping vegetation cover more open (Knisley 2011). Prescribed fire in late autumn could also be a useful tool for sustaining habitat once larvae are in deeper overwinter burrows.