Amblycheila schwarzi

Distinguished from other North American tiger beetles by its large size (25–38 mm), flightless condition, and nocturnal habits. Differs from congeneric species by geographic distribution. Larvae can be identified by extremely large size (up to 62 mm for third instar), two pairs of eyes with the anterior pair distinctly larger than the posterior pair, and distinctly separated middle and inner hooks on the fifth abdominal segment (not touching at the base). Larval burrows are large (6–8 mm diameter), almost perfectly round with clean beveled edges, slightly D-shaped to match larval head morphology, and may extend to depths of one meter or more.

Grassland and prairie habitats with barren soil patches among vegetation. Favors clay banks near streams, ravines, and talus slopes with sufficient incline. In Oklahoma, found in mixed-grass prairie beneath flat-topped mesas and associated ravines. Adults construct burrows in clay soils.

Southern United States. Specific range details limited; known from western habitats including the Mojave region. Museum specimens have been documented from Utah.

Adults active nocturnally. Precise seasonal activity period not well documented, though collecting success has been reported during summer months (July).

Larval development extends through at least three instars. Third instar larvae reach exceptional size (up to 62 mm). Larval burrows are constructed in clay soils to depths potentially exceeding one meter. One individual collected as second instar in 2009 pupated after approximately four years, with adult emerging in spring. Pupation occurs within plugged burrow. Duration of larval stage estimated at multiple years (possibly 4+ years based on limited rearing data).

Adults are strictly nocturnal and flightless. Adults construct and occupy burrows in clay soils, spending much time within them. Adults have been observed to accept caterpillars as prey in captivity. Multiple adults can be maintained together without apparent cannibalism under proper conditions. Larvae are sit-and-wait predators at burrow entrances, using large sickle-shaped jaws to capture prey. Larvae brace against burrow walls using abdominal hooks when capturing prey to prevent extraction.

Predatory role as both larvae and adults. Larval burrows contribute to soil aeration and structure in clay habitats.

Subject of interest to entomologists and collectors due to large size, rarity, and basal phylogenetic position. Can be collected using nocturnal searching with headlamps. Larvae can be extracted from burrows using grass stem 'fishing' technique or careful excavation. Rearing from larva to adult has been accomplished in captivity using native soil substrates.

• Amblycheila cylindriformisSimilar large size and habitat preferences; distinguished by geographic distribution (Great Plains region from Texas to South Dakota)
• Amblycheila hoversoniSimilar exceptionally large larval size; distinguished by geographic distribution (South Texas)
• Tetracha speciesLarvae share simple thornlike hooks, but Tetracha larvae have middle and inner hooks touching at the base rather than distinctly separated, and lack the stout hair clusters around hook bases present in Amblycheila
• Cicindela speciesLarvae have curved sickle-shaped middle hooks rather than simple thornlike hooks, and only one pair of eyes visible

• tiger beetle
• flightless
• nocturnal
• basal lineage
• large size
• clay soil
• burrowing

• BugGuide
• Wikipedia
• GBIF taxonomy match
• iNaturalist taxon
• Catalogue of Life
• How to collect larvae of Amblycheila cylindriformis | Beetles In The Bush
• Amblycheila success! | Beetles In The Bush
• Another look at North America’s most beautiful longhorned beetle | Beetles In The Bush
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