Pleotrichophorus obscuratus Hille Ris Lambers 1966

Pleotrichophorus obscuratus Hille Ris Lambers, 1966:605–607; 1969:166

DIAGNOSIS.—This species is distinctive among short cornicled species (viz., P. brevinectarius, P. infrequenus, P. filifoliae, P. pseudopatonkus, P. triangulates) with its entirely brown appendages, anal plate, and cauda. The short (.09–. 12 mm), needle-tipped last rostral segment is also diagnostic.

DESCRIPTION.—Apterous Viviparous Females: Color in life pruinose, grayish green (original description). Cleared specimen with light brown head, rest of body pale; antennae brown with basal 2 flagellar segments paler; entire legs, rostrum from third segment, entire cornicles, cauda, subgenital and anal plates brown. Body 1.30–1.80 (1.59, n = 6) mm long, .37–.40 (.390, n = 7) mm wide across eyes. Head with slightly developed frontal tubercles; mf 1p, lf 2p, vlf 1p, df 20–28 (25.71 ± 2.54, n = 7), vf 6–8 (usually 6), pc 2p, ac 4, md 2–4 (usually 3) on each side; dorsal setae funnel-shaped, with rather long stems (about ¾ entire length for anterior ones); ventral setae with vf flattened to slightly expanded on apices, pc, ac, and md much smaller and pointed; mf .0418–.0550 (.0489, n = 14), df–1 .0440–.0550 (.0490, n = 14) mm long. Antennal segment I slightly produced on inner distal margin, faintly imbricate, with 4–5 pointed or blunt-tipped setae aside from basal pointed one on dorsum. A.s.II with blunt setae. A.s.III with blunt to pointed setae, longest about 14 basal diameter of segment; bearing 1 sensorium. A.S.IV and V subequal, about ¾ length of a.s.III; a.s.VI with unguis 3 ¼ to 4 ¼ times (3.58, n = 13) as long as base.

Body with dorsum pale, membranous; with 2 pairs of rows of light brown pleural intersegmental patches on abdomen and brown sclerotic spiracular plates; setae moderately dense and similarly shaped to those on dorsum of head. Cauda gradually tapering to acute but rounded tip; spiculate; with 2 pairs lateral and 1 posterodorsal setae. Cornicles .09–.13 (.108, n = 12) mm long, .41–.67 times (.56 ± .05, n = 12) as long as cauda; cylindrical, almost uniformly thick; imbricate-spiculate, with spicules rather large, sharp. Legs bearing 3, 3, 3 setae on 1st tarsal joints. Last rostral segment .09–.12 (.11, n = 7) mm long, .82–1.22 (1.12 ± .06, n = 11) times as long as hind ta–2; tapering just past pl setae, from there drawn into thin cylindrical needle, about ⅓ total length of segment; with 1 basal, 2 dorsal, and 3 lateral pairs of setae, ml and pi about ½ al in length.

Measurements (in mm) of 2 paratypes: BL 1.30 and 1.45, We .37 and .39; a.s.III .28–.31 (.293), a.s.IV .21–.28 (.24), a.s.V .20–.21 (.205), a.s.VI .09–.10 (.095) + .37–.38 (.373); cornicles .10–.12 (.108), cauda .17 and 18; hind tibiae .67–.73 (.69), hind ta–2 .09–.10 (.093), and rostrum IV+V both .11.

Alate Viviparous Female: Unknown.

Sexuales: Unknown.

HOST.—Artemisia californica.

DISTRIBUTION.—California.

SPECIMENS EXAMINED.—Two paratypes, with same data as holotype; 5 apt.v.f., Riverside, California at U.C., 20–I–1965, RCD, on Artemisia californica (RCD coll.).