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 10-13 mm and blackish to dark olive above. Maculations reduced to a few spots and a distinct short but straight line extending inward on outer tip of elytra. A row of small but distinct blue-green pits runs parallel to inner margin of the elytra. The body is relatively slender, especially at the thorax. Below, metallic blue-green on abdomen, coppery-purplish on sides of thorax. Forehead not hairy, labrum with one tooth, and first antennal segment with only one sensory setae. C. punctulata punctulata the only subspecies of Punctured Tiger Beetle in Montana.

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 (= Cicindelidia) punctulata punctulata a summer species, April to November across the range but most active in July (Larochelle and Larivière 2001, and Pearson et al. 2015); June to mid-September in North Dakota and Colorado (Kirk and Balsbaugh 1975, and Kippenhan 1994), June to October in Nebraska (Carter 1989). In Montana, records from late June to late September (Nate Kohler personal communication, iNaturalist 2023).

The following comes from Wallis (1961), Kippenhan (1994), Acorn (2001), and Pearson et al. (2015). The combination of dark body with maculations reduced to a few spots and short thin lines, the row of small blue-green pits parallel to the inner margin of the elytra, the labrum with a single tooth, and a non-hairy forehead, are diagnostic in our region. The dark form of the Cowpath Tiger Beetle (Cicindela purpurea auduboni), the Long-lipped Tiger Beetle (Cicindela longilabris), and the Prairie Long-lipped Tiger Beetle (Cicindela nebraskana) are heavier-bodied (broader) with different maculations (or none) than Cicindela (= Cicindelidia) punctulata punctulata, and all lack the row of small blue-green pits on the elytra. The subspecies C. punctulata chihuahuae of the southwestern US reaches southern Idaho (Pearson et al. 2015, Gotschall 2021), is bright metallic green to blue-green or bright blue above with maculations absent or reduced to a few spots. C. punctulata chihuahuae has a broad area of intergradation with C. punctulata punctulata in southern Wyoming and all of Colorado but has not been reported from Montana.

Non-migratory but capable of dispersal. When wings fully developed (macropterous), it is a strong flier, and fast runner; sometimes attracted to lights in cities and the field in large numbers (Larochelle and Larivière 2001).

Adult and larval tiger beetle habitat is essentially identical, the larvae live in soil burrows (Knisley and Schultz 1997). Cicindela (= Cicindelidia) punctulata punctulata associated with disturbed and undisturbed habitats, including dirt and paved roads, road cuts, roadside ditches, cow paths, dirt paths, eroded banks and gullies, badlands, rocky hillsides, to treeline in high mountains, strip mines, sand dunes, blowouts, sand bars, yards, city lawns and parks, garden paths, grasslands and prairie, pastures, cultivated fields, plowed fields, city vacant lots and parking lots, sidewalks, forest paths, hard-packed open ground that is dry and sparsely vegetated soil of sand or sandy loam, saline flats, lake and river margins, and dry mudflats (Vaurie 1950, Willis 1966, Hooper 1969, Kirk and Balsbaugh 1975, Knisley 1984, Carter 1989, Kippenhan 1994, Acorn 2001, Larochelle and Larivière 2001, Kritsky and Smith 2005, and Pearson et al. 2015). In Montana, habitat includes stream, river, and pond margins, wetland edges, badlands, large sandy blowouts, dunes, saline flats, sandy two-tracks, grasslands, and urban sidewalks (Vaurie 1950, Winton 2010, Nate Kohler personal communication, Paul Hendricks personal observation, and iNaturalist 2023).

Larval and adult tiger beetles are predaceous. In general, both feed considerably on ants (Wallis 1961, and Knisley and Schultz 1997). Adult diet in the field includes ants, nymphal seed bugs (lygaeids), grasshoppers (acridids), beetles (chrysomelids, carabids), and worms; in captivity ants, beetles (carabids), flies, and lean meat. Larval diet in the field includes a variety of small arthropods; in captivity flies (drosophilids, muscids, calliphorids), cricket nymphs (gryllids), and lean meat (Mury Meyer 1987, and 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 (= Cicindelidia) punctulata punctulata has a broad range of ecological tolerance (eurytopic), occurring in a variety of disturbed and undisturbed habitats. Larval burrows excavated among grass clumps and weeds, dry mossy sites, or willow and cottonwood seedlings, usually in hard-packed sand, clay, or loam, Larvae can survive flooding (hypoxia) up to 180 hours, adults for about 15 hours (Larochelle and Larivière 2001, and Brust and Hoback 2009). Adults are both diurnal and nocturnal, gregarious. Basks, stilts, forages, and shuttles to shade at 33.4-37.7°C, inactive at 38-39°C. During hottest times of day seen going in and out of mud cracks or sheltering in shade of vegetation, sticks and rocks; hides under wood on cloudy or cool days. Attracted to artificial lights at night. Very wary during day, sometimes difficult to approach; when pursued makes quick flights, emits strong fruity scent when captured. Predators include birds (American crow (Corvus brachyrhynchos), flycatchers, European Starling (Strunus vulgrais), American Kestrel (Falco sparverius), American Robin (Turdus migratorius)), amphibians (frogs, toads), White bass (Morone chrysops), asilid (robber) flies, possibly bats; larval parasites include bombyliid flies and tiphiid wasps (Larochelle and Larivière 2001, Brust et al. 2004). C. punctulata adults especially sensitive to ultrasound in the range of 25-50 kHz and makes nocturnal flights (Vaurie 1950, Yager et al. 2000, and Larochelle and Larivière 2001). Associated tiger beetle species across the range include Cicindela (=Eunota) circumpicta, C. decemnotata, C. denverensis, C. formosa, C. fulgida, C.lengi, C. limbalis, C. (=Ellipsoptera) nevadica, C. (=Cicindelidia) nigrocoerula, C. (=Cicindelidia) obsoleta, C. (=Cicindelidia) ocellata, C. pulchra, C. purpurea, C. repanda, C. sexguttata, C. (=Parvindela) teriricola, C. (=Eunota) togata, and C. tranquebarica (Kippenhan 1994, Larochelle and Larivière 2001, and Kritsky and Smith 2005).

Life cycle of Cicindela (= Cicindelidia) punctulata punctulata life cycle is 1 year over most of range, possibly 2 years in the north; overwinters as third-instar larvae (Acorn 2001, Larochelle and Larivière 2001, and Pearson et al. 2015). Adults mate during June-September, (Vaurie 1950, and Larochelle and Larivière 2001). Females lay eggs during June-July from the ground surface during the day at depths of 5-8 mm, eggs hatch in about 14 days. Larval burrows about 14-65 cm deep, deeper in winter than summer, duration of larval stage is 10 months. After hibernation larvae feed from April-June; pupation in May-June lasts 10-14 days, tenerals (fresh adults) emerge in May-July, adults live about 2 months (Criddle 1907, Shelford 1908, Larochelle and Larivière 2001, Brust et al. 2012, and Pearson et al. 2015). No information about reproductive characteristics in Montana.

Not considered rare or in need of special conservation management (Knisley et al. 2014). As one of the most widespread tiger beetles east of the Rocky Mountains (Pearson et al. 2015), Cicindela (= Cicindelidia) punctulata punctulata occurs in many human-altered landscapes, including grazed pastures and rangelands, agricultural fields, orchards, urban yards and clearings, powerline cuts, sandy and clay roads and paths, and can benefit from the maintenance or judicious creation of these habitats in Montana and elsewhere (Knisley 2011). Encroachment of open areas by native or exotic plants through the process of succession might become a problem locally as this species prefers open terrain (Knisley 1979). Local disturbance could also be a problem for some populations where larval burrows are damaged or destroyed by trampling from livestock drawn to water sources, but grazing at appropriate times and stocking levels could also be beneficial by keeping vegetation cover more open (Knisley 2011).