Montana Field Guide

The following is taken from Wallis (1961), Kippenhan (2007), Pearson et al (2015). Body length is 8-11 mm. Above is variable, dark brown, blue or black. Maculations may be absent or thin, the middle band is absent or most often a transverse dash with marginal origin, never with complete marginal band. Body is long and narrow, but relatively small for a tiger beetle, with relatively straight and parallel outer margins of the elytra. Below is metallic blue-green or purplish, with sparse white hair-like setae on sides of thorax and abdomen. Forehead is not hairy, labrum medium, with 1 tooth. Intergrades with C. t. cinctipennis near the borders with Saskatchewan and the Dakotas have more complete or thicker maculations.

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). Adult Cicindela (=Parvindela) terricola terricola a summer species, most common June to early August (Larochelle and Larivière 2001, and Pearson et al. 2015); July to August in Nebraska (Carter 1989), June to August in South Dakota (Kirk and Balsbaugh 1975), most common in June in western North Dakota (Kritsky and Smith 2005). No information for Montana.

The following largely comes from Wallis (1961), Kippenhan (2007), Pearson et al. (2015). This is the smallest tiger beetle in Montana, and not likely to be confused with any other species; size and the maculations are unique. Of the two subspecies present in the prairie regions of the state, C. t. terricola is variable in color and maculations, but usually dark brown with reduced maculations, the middle band, if present, is often reduced to a transverse dash originating on the elytral margin but never with a complete marginal band. Intergrades with C. t. cinctipennis display intermediate markings. C. t. cinctipennis is brown, greenish brown to blue above with complete maculations, middle band marginal in origin with an indistinct foot, usually with a complete marginal band. There is a lack of consensus on the number and validity of subspecies across the species range (Kippenhan 2007, Woodcock et al. 2007, Pearson et al. 2006, 2015). C. (=Parvindela) pusilla considered a synonym for C. (=Parvindela) terricola and all the accepted subspecies by some authorities, but a separate species by others (Kippenhan 2007, and Pearson et al. 2015).

Non-migratory but capable of dispersal. Wings fully developed (macropterous) but normally a weak flier, and fast runner (Larochelle and Larivière 2001, and Pearson et al. 2015).

Adult and larval tiger beetle habitat is essentially identical, the larvae live in soil burrows (Knisley and Schultz 1997). Across the range Cicindela (=Parvindela) terricola terricola is associated with sparse prairie or grassland vegetation, wet or dry, clay, loamy or muddy soil, alkaline or salty flats, dry creek beds, salt lake margins, irrigation ditches, muddy or gravelly banks along rivers, river bars, badlands, gravel pits, wooded fields, and agricultural fields (Criddle 1907, 1910, Vaurie 1950, Wallis 1961, Kirk and Balsbaugh 1975, Carter 1989, Larochelle and Larivière 2001, Kritsky and Smith 2005, and Pearson et al. 2015). In Montana, habitat is poorly described but probably similar to elsewhere across its range; includes areas of sparse grass or low vegetation with openings, alkaline lake shores, saline spots near roads (Vaurie 1950).

Larval and adult tiger beetles are predaceous. In general, both feed considerably on ants (Wallis 1961, and Knisley and Schultz 1997). Diet of adult and larval C. (=Parvindela) terricola not described but probably includes various small arthropods (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 (=Parvindela) terricola terricola has a broad range of ecological tolerance (eurytopic). Adults are diurnal, and mostly solitary; very wary, when pursued often runs and seeks grass cover; remains active late into afternoon or early evening (Vaurie 1950, Larochelle and Larivière 2001, and Pearson et al. 2015). Predators of adults are not described but probably include birds, spiders, and robber flies (Asilidae). Associated tiger beetle species include Cicindela denverensis, C. duodecimgutta, C. fulgida, C. lengi, C. limbalis, C. nebraskana, C. (=Ellipsoptera) nevadica, C. purpurea, C. repanda, C. scutellaris, and C. tranquebarica (Kritsky and Smith 2005).

Life cycle of Cicindela (=Parvindela) terricola terricola is probably 2 years, third instar larvae overwinter (Acorn 2001, Larochelle and Larivière 2001, and Pearson et al. 2015). Little information otherwise. No information on reproductive characteristics for Montana.

Cicindela (=Parvindela) terricola terricola not considered rare or in need of special conservation management (Knisley et al. 2014). In general, the subspecies benefits from the creation or maintenance of certain anthopogenic habitats, such as irrigation ditches (Knisley 2011). Changes in irrigation that affect the creation or occurrence of saline mudflat habitats within grasslands could have a negative impact on some populations. Some colonies (particularly the larval burrows) could be impacted by trampling through livestock overgrazing and attraction to water sources, but grazing at appropriate times and stocking levels could also be beneficial by keeping vegetation cover more open (Knisley 2011).