P. tremulae, Boerner , 1940

Nowinska, Agnieszka, Mroz, Ewa & Depa, Lukasz, 2017, Sexual morphs of Pterocommatremulae Boerner, 1940 (Aphididae, Aphidinae) with description of male reproductive system, ZooKeys 686, pp. 125-136 : 126-129

Description of sexual morphs of P. tremulae, Boerner, 1940

Oviparous female.

Body oval, 3.66-4.03 mm long (Fig. 1), grey to brightly brown, significantly convex. Head and pronotum dark and sclerotised; mesonotum with marginal sclerites, and spinal sclerites broken into smaller scleroites in the middle; metanotum with weak marginal sclerites only. Mesothoracic furca separated, but with band of dark sclerotisation between them, giving the impression of being joined. Antenna 6-segmented, brownish, with base of antennal segment III paler (Fig. 2A), 1.72 -1.92 mm long, 0.47-0.48 of body length. Antennal segment III 0.64-0.71, IV 0.26-0.29, V 0.26-0.31, VI 0.37-0.41 mm long; length of antennal segment III: 2.39-2.50 of the length of antennal segment IV, 2.29-2.44 of antennal segment V; processus terminalis 0.23-0.26 mm long, 1.60-1.90 of VIa. Antenna covered with long, erect hairs, 0.11-0.13 mm long. Number of secondary rhinaria on III antennal segment: 13-20 (Fig. 2), on IV antennal segment 0. Base of antennal segment VI with 6-8 erect hairs. Rostrum 0.90-1.10 mm long, 0.25-0.27 of body length, with ultimate rostral segment 0.22-0.23 mm long, 1.27-1.30 of second segment of hind tarsus, 0.33-0.34 of III antennal segment, 0.72-0.77 of siphunculus, with 12-13 accessory hairs (Fig. 1). Legs dark, with brighter bases of femora and coxae, second segment of hind tarsus 0.17-0.18 mm long; legs covered with erect hairs, their length on tibia 0.10-0.12 mm. Hind tibia swollen with ca. 150-200 scent plaques (Fig. 2B).

Abdomen membranous, covered with dense pubescence. Length of hairs on abdominal tergite V 0.17-0.19 mm. Spinal sclerites only on VI and VII segment: on VI weakly developed, broken into minute scleroites. Intersegmental sclerotic insertions dark. Marginal slerites present on abdominal tergites I and V, sometimes also on VI but broken into smaller scleroites. Marginal tubercles present always on abdominal tergites I-IV, sometimes also on V-VII, their diameter at most as the diameter of spiracles, always dark pigmented. Number of hairs on abdominal tergite VIII ca. 50, their length 0.16-0.17 mm. Cauda rounded, dark pigmented, covered with many hairs (Fig. 2C). Genital plate semicircular, dark pigmented, 0.47-0.50 mm wide, covered with many hairs. Siphunculi pale, cylindrical, but may be slightly swollen in the distal half (Fig. 2C), 0.28-0.32 mm long, slightly darker at the apex, with very delicate flange, 0.44-0.45 of the length of antennal segment III.

Alate male.

Body dark, brownish, 2.87-3.03 mm long (Fig. 3); head sclerotized, with ocelli well developed and big, multifaceted eyes with triommatidium. Antennae 6 segmented (Fig. 4A), 1.74-1.92 mm long, 0.61-0.65 of body length, brownish, only slightly paler than legs. Antennal segment III 0.63-0.71, IV 0.29-0.33, V 0.29-0.33, VI 0.38-0.44 mm long; length of antennal segment III: 1.62-1.63 of the length of antennal segment IV, 2.12-2.13 of antennal segment V; processus terminalis 0.22-0.27 mm long, 1.43-1.74 of VIa. Antenna covered with long, erect hairs, 0.09-0.11 mm long. Number of secondary rhinaria on antennal segment III: 73-105 (Fig. 4A), on antennal segment IV: 27-43, V: 20-26, VI: 0-2. Base of antennal segment VI with 8-10 erect hairs. Rostrum 1.15-1.22 mm long, 0.38-0.42 of body length, with ultimate rostral segment 0.19-0.21 mm long, 1.17-1.25 of second segment of hind tarsus, 0.29-0.31 of III antennal segment, 0.94-1.00 of siphunculus, with 11-13 accessory hairs. Thorax heavily sclerotized, winged. Forewings with veins weakly sclerotized, medial vein branched twice. Legs uniformly brownish, only bases of femora slightly paler, covered with erect hairs 0.12-0.13 mm long. Second segment of hind tarsus 0.15-0.17 mm long.

Abdomen membranous, covered with hairs 0.010-0.015 mm long, with spino-pleural sclerites on abdominal segments I-VII often divided in the middle, and on segment V broken into smaller slceroits. Marginal sclerites present on all abdominal segments, with spiracles in the anterior margins of the sclerites and with conspicuous marginal tubercles (Fig. 4B), dark pigmented, on segments I-IV and VI-VII, occasionally also on V. Siphunculi pale, 0.19-0.22 mm long, 0.30-0.32 of antennal segment III, tapering, with weakly swollen apical part and small flange (Fig. 4C). Cauda small, pigmented, semicircular, sparsely covered with hairs. Genital apparatus sclerotized, parmeres conspicuous, dark, densely covered by relatively short hairs; base of the membranous aedeagus less sclerotized, sparsely covered by very short hairs (Fig. 4D).