Subspecies Thyanta custator accerra

Thyanta custator Stål, 1872 (1)

Thyanta pallido-virens Banks, 1910 (1)

Thyanta accerra Deay & Gould, 1935 (1)

Thyanta pallidovirens accerra Ruckes, 1957 (1)

Thyanta pallidovirens spinosa Ruckes, 1957 (1)

There is a great deal of variation in this species, which has caused a history of taxonomic confusion. Its color can be anywhere from green to tan to dark brown and sometimes possesses a variable red band across the pronotum. Humeral spines are sometimes present. (1)

It is difficult to distinguish from Thyanta pallidovirens. Typically, T. custator accerra has black dots on the lateral portions of the abdomen that are larger than the nearby spiracles, while T. pallidovirens usually lacks the spots completely or has pale ones that are smaller than the spiracles(1). But this character may not be useful in the parts of California where the spinosa form (see Remarks, below) of T. custator accerra overlaps in range with T. pallidovirens because the spinosa form lacks these spots(1). The humeral spines that are common in the spinosa form may help to separate it from T. pallidovirens in areas where the ranges overlap. While the maps are from 1992 and ranges could be different today, T. pallidovirens is not expected to occur in Arizona(1).

The species is much more easily separated from Thyanta custator custator, which has black anterolateral pronotal margins, like Thyanta calceata(1).

This is the most wide-ranging member of the genus. In 1992, Rider & Chapin reported its distribution throughout the eastern 2/3 of the US to eastern Montana, eastern and southern Wyoming, Utah, Nevada, and southern California (1).

In 1957, Ruckes separated Thyanta pallidovirens into four subspecies (2): Thyanta pallidovirens pallidovirens from the western US, Thyanta pallidovirens accerra from the eastern US, Thyanta pallidovirens spinosa from the southwestern states, and Thyanta pallidovirens setosa largely from the Great Basin(2).

Chromosomal studies and cross-breeding experiments have determined that the males of T. pallidovirens pallidovirens and T. pallidovirens setosa have a chromosome count of 14 + XY while those of T. pallidovirens spinosa and T. pallidovirens accerra) have a count of 16 + XY(1)(3).

Now, T. pallidovirens pallidovirens and T. pallidovirens setosa fall under Thyanta pallidovirens while T. pallidovirens accerra and T. pallidovirens spinosa fall under Thyanta custator accerra.