Pleotrichophorus quadritrichus pallidus Corpuz-Raros & E. F. Cook 1974

Pleotrichophorus quadritrichus pallidus

DESCRIPTION.—Apterous Viviparous Female: Color in life unknown. Cleared specimen with head slightly dusky, body pale and membranous; antennal segments I and II pale or dusky, concolorous with head, flagellum dark brown from apices of segment V; ventral head sclerites and last 2 rostral segments dusky but with extreme apex darker; coxae to femora of all legs dusky or very pale brown, bases and apices of tibiae, entire tarsi brown, remainder of tibiae pale like body; cornicles, cauda, anal and subgenital plates dusky or pale brown. Body 1.22–1.46 (1.36, n = 12) mm long, .32–.37 (.348, n = 13) mm wide across eyes. Laterofrontal tubercles relatively less developed than in typical subspecies, mesofrontal tubercle broad, low; mf 1p, lf 1–2 (usually 2) on each side, vlf 1p, df 24–36 (28.92 ± 1.98, n = 13), vf 5 to 7, pc 2p, ac 4–5, md 2–4 (usually 3 on each side); anterior dorsal setae elongate, slightly expanded, posterior shorter, more widely flaring, funnel-shaped; ventral setae with vf and pc blunt or slightly expanded, others pointed; mf .0330–.0572 (.0457, n = 22) and df–1 .0396 (n = 23) mm long. Antennal segment I slightly produced mesodistally, faintly imbricate, with 3–6 long, blunt to slightly knobbed setae aside from small pointed one on dorsum. A.s.II almost smooth, usually with long knobbed setae. A.s.III faintly imbricate, setae all with knobbed or bulbous apices, longest subequal to basal diameter of segment; with only 1 sensorium. A.s.IV and V subequally long averaging ¾ length of a.s.III; a.s.VI with unguis 3½ to 4½ times (3.89, n = 25) length of its base.

Dorsal body integument smooth on disk, becoming spiculate caudally from about the abd.s. 5; moderately densely covered with funnel- or cone-shaped setae. Cauda .18–.25 (.212, n = 13) mm long; elongate, constricted on basal 14, acutely rounded at apex; spiculate; and bearing 2 pairs lateral and 1 posterodorsal setae. Cornicles .17–.26 (.219 ± .01, n = 26) mm long, about as long as cauda (co/ca, .94–1.19, m = 1.05, ± .028, n = 20); cylindrical, with widest diameter at bases; distinctly imbricate-spiculate, spicules rather large, blunt. Legs with 3,3,3 hairs on 1st tarsal joints, hind tibiae .69–.90 (.80, n= 21), and hind ta–2 .11–.12 (.116) mm long. Rostrum IV+V .12–.13 (.122 ± .003, n = 14) mm long, slightly longer than hind ta–2 (1.08–1.14 times, m = 1.09 ± .01, n = 20); slender at base, distal ½ produced into cylindrical needle; with 1 basal, 2 dorsal, and 3 lateral pairs of setae, al about twice as long as ml and pl setae.

Measurements (in mm) of holotype: BL 1.34, We .37; a.s.III .36 and .37, a.s.IV .26 and .25, a.s.V both .24, a.s.VI .11 + .40 and .11 + .39; cornicles both .24, cauda .22; hind tibiae both .75, hind ta–2 both .11, and rostrum IV+V .12 mm.

Alate Viviparous Female: Unknown.

Oviparous Female: Very much like viviparous aptera and differing only as follows: body setae relatively sparser, longer, more narrowly expanded; dorsal seta on a.s.II often absent (e.g., in 63.7% of 11 segments); cauda stouter, not distinctly constricted, broadly rounded at apex, bearing more posterodorsal hairs (1–5, m = 3.75, n = 8); subgenital plate with more setae; basal ⅓ of hind tibiae enlarged, with numerous pseudosensoria.

Measurements (in mm) of 8 paratypes: BL 1.26–1.52 (1.42), We .34–.38 (.358), a.s.III .33–.45 (.411), a.s.IV .30–.36 (.325), a.s.V .28–.31 (.300), a.s.VI .10–.12 (.113) + .40–.53 (.474); cornicles .20–.25 (.213), cauda .19–.20 (.191); hind tibiae .81–1.06 (.98), hind ta–2 .11–.13 (.121), rostrum IV+V .12–.14 (.130), mf .0440–.0550 (.0499), and df–1 .0506.0550 (.0541). Proportions of a.s.III:IV:V, 1: .68–.88 (.79): .64–.77 (.73); VIu/VIb 3.33–4.64 (4.21); co/ca 1.05–1.25 (1.12) and rostrum IV+V/ hind ta–2 1.00–1.18 (1.06).

Alate Male: Associated with viviparous and oviparous females from Kanab Creek Canyon, Utah, are strikingly different from males of the typical subspecies from California in the long, pointed to blunt dorsal head and body setae; the conspicuous abdominal sclerotizations, spinal contiguous with pleural sclerites on segments 1 to 5 to 8; smaller ovate sclerites on segments 2 to 3 where sclerites are separate; more sensoria on all antennal segments bearing them.

Head, thorax, entire antennae, entire legs except extreme bases of tibiae, abdominal sclerites, cornicles, genital capsule, and apical 2 rostral segments dark brown; wing veins lighter brown; remaining areas of abdomen pale, membranous. Morphologically different from viviparous aptera in having head and body setae all pointed or merely blunt; presence of abdominal sclerotizations; presence of fewer df setae (10–12, m = 11, n = 3) and sparser body setae; presence of more sensoria on a.s.III (43–49, m = 46.0, n = 4) and their presence also on a.s.IV (30–31, m = 30.3, n = 4); in having shorter cornicles and cauda and slightly shorter rostrum IV+V/ hind ta–2 ratio. Genitalia consisting of 2 oblong, setaceous parameres, aedeagus cylindrical, apically rounded.

Measurements (in mm) of 3 paratypes: BL 1.52–1.60 (1.56), We .34–.37 (.353); a.s.III .48–.53 (.505), a.s.IV .42–.44 (.430), a.s.V .34–.41 (.378), a.s.VI .13–.15 (.143) + .57–.61 (.587); cornicles .14–.16 (.143), cauda .12–.13 (.125); hind tibiae .97–1.09 (1.05), rostrum IV+V .12–.13 (.127); mf .0286–.0396 (.0334), and df–1 .0352–.0484 (.0396). Proportions of a.s.III:IV:V, 1: .83–.88 (.86); .69–.79 (.75); VIu/VIb 3.87–4.38 (4.11); co/ca 1.08–1.33 (1.19); and rostrum IV+V/ hind ta–2 .92–.93 (.926).

HOST.—Artemisia tridentata.

DISTRIBUTION.—Utah–Arizona border.

TYPES (all in EOE coll.): Holotype, apt.v.f., Fredonia, Arizona, 13–X–1955, GFK, on Artemisia tridentata; specimen at 1:00 o’clock of slide with 2 apt.v.f., 1 ovip.f. and 5 ny. Paratypes: specimens on same slide as holotype; 5 apt.v.f. and 5 ny. with same data as holotype but on a different slide; 6 apt.v.f., 4 ovip.f., 3 al.m., and 2 ny., Kanab Creek Canyon, Utah, 15–X–1955, GFK, on A. tridentata (mounted on 3 slides); 3 apt.v.f., 3 ovip.f., and 6 ny., Mt. Carmel Jct., Utah, 13–X–1955, on A. tridentata (2 slides).