Cicindela obsoleta Say

Mawdsley, Jonathan R., 2009, Geographic variation in U. S. populations of the tiger beetle Cicindela obsoleta Say (Coleoptera: Cicindelidae), Insecta Mundi 2009 (94), pp. 1-10 : 2-4

Cicindela obsoleta Say

Cicindela obsoleta Say (1823:143) Type destroyed, but identity well established.

Diagnosis. A large to very large tiger beetle (length 13-20 mm) associated with desert grasslands and woodlands in Arizona, Colorado, Kansas, New Mexico, Oklahoma, and Texas, with isolated populations in Arkansas and Missouri. Dorsal coloration may be matte black, brown, blue, olive-green, or bright green, but never strongly iridescent. Elytral markings variable, with yellow or white maculae and/or fasciae

often present. Pronotum subquadrate, with a thin band of reclinate setae along the lateral edges of the disc.

Subspecific taxonomy. Four subspecies are recognized here, confirming the traditional taxonomic arrangement in Cicindela obsoleta ( Freitag 1999; Pearson et al. 2006). Of the 1,424 specimens that I examined, 1,393 could be unequivocally assigned to a single subspecies on the basis of their elytral markings. The remaining 31 specimens are more or less intermediate between the two forms that have been conventionally recognized as C. o. obsoleta and C. o. santaclarae Bates. As discussed below, I interpret these forms as intergrades between these two subspecies.

Cazier (1954) reviewed the Mexican subspecies of C. obsoleta and recognized two additional subspecific taxa, C. o. latemaculata Becker from Durango and C. o. juvenilis Horn from Jalisco, Sinaloa, and Sonora. However, Cazier’s treatment of C. obsoleta is limited, as it was based on material collected at just 11 localities in México ( Cazier 1954). A more extensive study of the Mexican forms is needed; Murray (1979) reports the discovery of Mexican specimens which do not fit into any of the currently-recognized subspecific taxa. Even the status of the two subspecific taxa C. o. latemaculata and C. o. juvenilis can be questioned. Cazier (1954) relied on the presence of wide elytral markings to separate C. o. latemaculata from the other subspecies of C. obsoleta . However, similar markings are present in individuals from U.S. populations of C. o. santaclarae (e.g. Figure 7, 9 ). Thus, C. o. latemaculata may ultimately prove to be a synonym of C. o. santaclarae. Likewise, C. o. juvenilis differs from the other subspecies of C. obsoleta in lacking dense setae on the proepisterna and metepisterna ( Cazier 1954), a significant morphological distinction which suggests that C. o. juvenilis may actually be a separate species. Additional material of these forms from additional collecting localities is needed in order to resolve these questions.

The following key is offered to assist in the separation of the U.S. subspecies of C. obsoleta Say. Users should be aware that putative intergrades between C. o. obsoleta and C. o. santaclarae have been collected in New Mexico and Texas and may also occur in Arizona (see further discussion in the section on intergrades below). These intergrades will run to C. o. santaclarae in this key.

Figures

Figure 1-9. Adult habitus photographs of pinned specimens of Cicindela obsoleta in NMNH. 1) Cicindela obsoleta obsoleta Say, male, Silver City, NM. 2) Cicindela obsoleta obsoleta, female, Carrizo Creek Picnic Area, Baca Co., CO. 3) Cicindela obsoleta obsoleta, male, Silver City, NM. 4) Cicindela obsoleta obsoleta X Cicindela obsoleta santaclarae, female, Silver City, NM. 5) Cicindela obsoleta santaclarae Bates, syntype female, Santa Clara, Chihuahua, México. 6) Cicindela obsoleta santaclarae, male, Ft. Wingate, NM. 7) Cicindela obsoleta santaclarae, female, Ft. Wingate, NM. 8) Cicindela obsoleta santaclarae, female, Ft. Wingate, NM. 9) Cicindela obsoleta santaclarae, male, Ft. Wingate, NM.