Pleotrichophorus packi brevis Corpuz-Raros & E. F. Cook 1974

Pleotrichophorus packi brevis

A collection of 5 apterous viviparous and 2 oviparous females (from Brigham Canyon, Utah, 3–X–1928, GFK, on Chrysothamnus nauseosus) exhibit several differences from P. packi, sensu stricto. A separate sub-specific treatment is proposed for these.

DESCRIPTION.—Apterous Viviparous Female: Measurements (in mm) of holotype and 4 paratypes: B.L. 2.36–2.60 (2.45), We .54–.56 (.548); a.s.III .71—.81 (.742), a.s.IV .69–.79 (.736), a.s.V .60–.71 (.649), a.s.VI .14–.16 (.149) + .84–.88 (.86); cornicles .64–.75 (.684), cauda .36–.41 (.394); hind tibiae 1.56–1.68 (1.64), hind ta–2 13–.15 (.145), rostrum IV+V .11–.12 (.112); mf .0374–.0572 (.0444), and df–1 .0374–.0484 (.0442). Proportions of a.s.III:IV:V, 1: .91–1.06 (.99): .85–.88 (.87); a.s.VIu/VIb 5.87–6.00 (5.94); co/ca 1.60–1.88 (1.74); rostrum IV+V/ hind ta–2 .73–.92 (.78 ± .06, n = 8). Number of sensoria on a.s.III 2–5 (3.5); number of df setae 11–16 (13.20 ± 2.39); number of lateral caudal setae 4–6 (5.1); posterodorsal caudal setae 2–4 (3.2).

Alate Viviparous Female: Unknown.

Oviparous Female: The oviparous female of P. p. brevis can be separated from that of P. p. packi in the same way as the viviparous aptera. The cornicles, however, are dark for a relatively longer portion, the distal ⅔, but not to the same extent as in P. packi packi. It differs from the apterous viviparous female in its shorter cauda, more elongate, less expanded dorsal head and body setae, the presence of more hairs on the subgenital plate, and by having the basal third of the tibiae thickened and bearing numerous pseudosensoria.

Measurements (in mm) of 1 paratype: B.L. 2.08, We .53; a.s.III .75 and .77, a.s.IV .77 and .78, a.s.V .69 and .70, a.s.VI .16 + .90 and .16 + .92; cornicles both .61, cauda .32, hind tibiae 1.58 and 1.60, hind ta–2 both .14, rostrum IV+V .12; mf .0242–.0374 (n = 3) and df–1 both .0440. Number of sensoria on a.s.III 5 and 7; number of df setae 11; number of lateral caudal hairs 4 and 6, and of posterodorsal hairs 5.

Male: Unknown.

HOST.—Chrysothamnus nauseosus.

DISTRIBUTION.—Known only from type-locality, in Brigham Canyon, Utah.

TYPES.—Holotype, apt.v.f. with data indicated above. Paratypes: 4 apt.v.f., 2 ovip.f., and 4 apt.ny. with same data as holotype. Holotype and all but 2 apt.v.f. paratypes in GFK coll., the latter in U. Minn. coll.