Description and conservation status of a new subspecies of cicindela tranquebarica (coleoptera: cicindelidae), from the san joaquin valley of california, u.s.a
2007
Knisley, C Barry | Haines, R Dennis
This paper describes a new subspecies of oblique-lined tiger beetle, Cicindela tranquebarica joaquinensis, from the San Joaquin Valley of California. This new subspecies is most closely related to C. t. vibex with which it intergrades along the margins of the San Joaquin Valley. The maculation pattern of C. t. joaquinensis, like that of C. t. arida is characterized by being reduced to only the apical lunules. However, C. t. arida is significantly smaller in body size, has microserrations on the elytra, is restricted to the Death Valley area and thus well separated from C. t. joaquinensis by both distance and the Sierra Nevada Mountains. A study of collection records indicated C. t. joaquinensis was historically present throughout much of the San Joaquin Valley in alkali sink or flat habitats. A search of the historic and many additional sites with these habitats produced only three extant populations of C. t. joaquinensis, all in patches of habitat that were less than three hectares in size. The extirpation of most populations of this beetle was caused by habitat loss from intense agricultural development in the San Joaquin Valley, especially cultivation for crops, cattle grazing, and water diversions and modifications related to irrigation. Increased vegetation is also reducing the open areas in the habitats needed by this species. Because of the very few and small extant populations and the elimination of nearly all of the alkali sink habitat, C. t. joaquinensis should be considered for endangered status by the U.S. Fish and Wildlife Service.
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