Amblycheila hoversoni

Distinguished from all other Western Hemisphere tiger beetles by its exceptional size. Separated from the related Amblycheila cylindriformis (Great Plains giant tiger beetle) by geographic range—A. hoversoni occurs in south and west-central Texas while A. cylindriformis is found further north in the Great Plains from Texas to South Dakota. The two species may overlap in Texas, but specific distinguishing characters for adults are not documented in available sources. Larvae can be distinguished from other tiger beetle genera by: two pairs of eyes with the anterior pair distinctly larger; simple, thornlike hooks on the 5th abdominal segment with the middle and inner hooks distinctly separated rather than touching at the base; and a cluster of short, stout hairs around the base of each hook.

Native prairie and grassland habitats, specifically on lower talus slopes with red clay/gypsum exposures. Based on congeneric A. cylindriformis ecology, likely associated with barren soil patches amongst vegetation, including clay banks near streams, ravines, and areas with sufficient slope for larval burrow construction.

Endemic to south and west-central Texas, United States. Distribution more restricted than the related A. cylindriformis, which ranges from Texas north through the Great Plains to South Dakota.

Adult activity period not explicitly documented in available sources. Based on congeneric A. cylindriformis, likely active during summer months with peak activity in June–July.

Larval development extends through at least three instars. Larval burrows are large (approximately 6–8 mm diameter for third instar), almost perfectly circular with clean, beveled edges, and oriented straight down from the surface; slightly D-shaped in cross-section to match the larva's head shape. Burrows may extend to depths of a meter or more. Larvae possess large, sickle-shaped, upward-facing mandibles for capturing prey. Development from second instar to adulthood has been observed to take over three years in laboratory conditions for congeneric A. cylindriformis; duration for A. hoversoni specifically is not documented.

Strictly nocturnal. Flightless adults move with a deliberate, lumbering gait, lifting each foot relatively high, rather than the rapid, jerky running typical of most tiger beetles. Adults have been observed to make burrows and spend considerable time in them. Larvae plug their burrow entrances for extended periods (months at a time) and reopen to feed voraciously when active.

Subject of interest to entomologists and collectors due to its exceptional size and restricted range. Has been reared in laboratory settings, though with difficulty—adults do not readily lay eggs in captivity.

• Amblycheila cylindriformisAlso a giant, flightless, nocturnal tiger beetle with somber coloration, small eyes, and lumbering gait. Distinguished by geographic distribution (Great Plains north of Texas) and slightly smaller maximum size; A. hoversoni is the larger species and is restricted to south and west-central Texas.

• flightless
• nocturnal
• endemic
• prairie
• giant
• western hemisphere largest

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• Wikipedia
• GBIF taxonomy match
• iNaturalist taxon
• Catalogue of Life
• How to collect larvae of Amblycheila cylindriformis | Beetles In The Bush
• Hunting the Great Plains giant tiger beetle | Beetles In The Bush
• The marvelously monstrous Microstylum morosum | Beetles In The Bush