Townsendiella californica Michener, 1936

Orr, Michael C. & Griswold, Terry L., 2015, A review of the cleptoparasitic bee genus Townsendiella (Apidae, Nomadinae, Townsendiellini), with the description of a new species from Pinnacles National Park, ZooKeys 546, pp. 87-104 : 94

Taxon classification Animalia Hymenoptera Apidae

Townsendiella californica Michener, 1936

Holotype.

female, pinned; Altadena, California; 6-26-35 [26 June 1935]; deposited in CAS (Type#4544).

Diagnosis.

This species is immediately separable from all other species by its wing venation. The marginal cell is the shortest of any Townsendiella , its maximum length significantly shorter than the distance from its apical tip to the apex of the wing. The posterior margin of the first submarginal cell is roughly twice the length of the second submarginal’s, while in other species the first submarginal cell is closer to 1.5 × the length of the second. The second submarginal cell forms a nearly symmetrical triangle with the distal vein nearly straight and nearly the same length as the proximal vein.

Distribution.

Townsendiella californica has a relatively restricted range in comparison to the other species of the genus. It is currently known from localities along the southern edge of the Transverse Range and north of the nearby Mt. San Jacinto. Interestingly, these collections are all along the edge of the California montane chaparral and woodlands ecoregion. It may be that this species, its host, or both inhabit a very narrow ecological niche.

Phenology.

The phenology of this species is difficult to ascertain due to few collection records, though it appears to be active from late April through June.

Bee hosts.

Uncertain. This species is hypothesized to be cleptoparasitic on Hesperapis (Zacesta) rufipes (Ashmead, 1899) based on observation of Townsendiella californica flying over a nesting aggregation of the former ( Michener 1936). Multiple attempts were made to confirm the host at the same site; the population has apparently been extirpated by urban sprawl from the Altadena, California area ( Stage 1966).

Floral hosts.

No floral records are known for this species.

Discussion.

This exceptionally rare species is known from the fewest specimens of any Townsendiella . As such, much remains to be discovered regarding its distribution, host specificity, and environmental constraints.