Aggregation-behavior
Guides
Tegrodera erosa erosa
Iron Cross Beetle
Tegrodera erosa erosa is a blister beetle (family Meloidae) endemic to southwestern North America. This large, colorful beetle occurs in dry valleys and hills of cismontane southern California and south into Baja California. Adults are active primarily in late spring and early summer, often forming immense feeding and mating aggregations. The subspecies is distinguished from the nominate form T. erosa inornata by its patterned elytra. Like other meloids, it contains cantharidin in its hemolymph, a compound toxic to mammals. The species is undergoing habitat retrenchment in southern California due to urban development.
Tegrodera latecincta
Soldier Blister Beetle, Iron Cross Blister Beetle
Tegrodera latecincta is a large, colorful blister beetle endemic to the Owens and Antelope valleys of eastern California. As the northernmost species in the genus Tegrodera, it is geographically isolated from its closest relative T. erosa by the San Gabriel and San Bernardino mountains, and from T. aloga by the Mojave Desert. Adults are active in late spring and early summer, often forming conspicuous feeding and mating aggregations. Like other meloid beetles, it possesses cantharidin in its hemolymph for chemical defense.
Trichoton sordidum
Trichoton sordidum is a small, flightless darkling beetle (Tenebrionidae) native to the Sonoran Desert borderlands of southern Arizona and northern Mexico. The species exhibits sophisticated behavioral thermoregulation, including photonegativity and temperature-dependent activity patterns. Under resource limitation or environmental stress, individuals form adhesive aggregations or physical clumps of 2–10 beetles as a threat evasion mechanism. Dispersal follows cohesive patterns consistent with Minimum Risk Distribution models.
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