Hentzia palmarum Hentz 1831

Hentzia palmarum (Hentz 1831)

Figs. 11–15

In the process of comparing this species to specimens of Hentzia alamosa new species from Big Bend Ranch State Park, Presidio County, Texas, several new records were discovered. For a description of this species see Richman (1989, pp. 296– 302, figs. 16–27).

New Records. — USA: Texas: 1 male, 4 females, Edwards County, near Rock Springs (30°0 1ʹ29ʺN, 100°12ʹ21ʺW), January 1994; 3 females, Mason County, near Mason (ca 30°44ʹ56ʺN, 99°13ʹ50ʺW), January 1994; 1 male, 5 females, Zavala County, near Nueces (ca 28°47ʹ18ʺN, 99°49ʹ0 9ʺW), January 1994. All specimens were taken from irrigation tubes in pecan orchards by J. W. Stewart. All specimens deposited in TAMUIC.

Discussion. —The scattered distribution of most Hentzia species in the western United States and Mexico, usually in riparian areas, suggests speciation events by the founder effect, with a few individuals being accidentally introduced (perhaps by storms) to isolated favorable habitats. The other possibility may be isolation of populations of more widely spread species (such as H. palmarum or H. fimbriata) in refugia because of desert expansion, followed by subsequent speciation events. The presence of Hentzia fimbriata in Sycamore Canyon is an exception to the isolated populations in other parts of the southwesten USA and northwestern Mexico, as this species is widespread in Mexico. It is likely that its distribution follows the Sierra Madre and the watersheds of Mexican rivers draining into the Gulf of California. Sycamore Canyon, which drains into the Rio Altar in the Rio de la Concepcion drainage in Sonora, and where the U.S. specimens of H. fimbriata have been collected, is unusual in the variety of jumping spiders found there that are primarily associated with other geographical ranges. These include Zygoballus rufipes Peckham & Peckham 1885 (Mexico and eastern United States), Phidippus tux Pinter 1970 (central Mexico), and Sarinda hentzi (Peckham & Peckham 1892) (eastern United States) (all collected by the author). Because of the similar morphological features, future research on the genus Hentzia should include mitochondrial DNA analysis of as many species as possible in order to clear up the actual phylogenetic source and relationships of these species, especially in the palmarum species group. This is unfortunately beyond the scope of this paper and would require collection of fresh material from Cuba and Mexico, as well as the USA, even if limited to the palmarum group.