Shenahweum minutum Davis
Creators: name: Wieczorek, Karina
name: Kanturski, Mariusz
name: Junkiert, Łukasz
Publisher: name: Zenodo
Year: 2013
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Aphidomorpha
Aphididae
Shenahweum
Shenahweum minutum

description: Shenahweum minutum Davis
(Figs 1, 2)
Drepanaphis minutus Davis, 1910: 195 Oviparous female (Fig. 1 a; Table 1). Color of live specimens unknown; mounted specimens: pale, light yellowish. Body egg shaped with elongate end of abdomen. Head with compound eyes and triommatidia. Head width 0.14– 0.15 times length of antennae. Frons semicircular, recessed with well-developed, smooth and diverging antennal tubercles. Head chaetotaxy: dorsal side with three pairs of fronto-orbital, forked setae - one pair of long (0.105 mm) setae located on well visible protuberances (Fig. 1 c) and two pairs fine and about a half shorter than the first pair setae; one pair of latero-dorsal and one pair of postero-dorsal, forked setae. Antennae 6-segmented, 1.37–1.54 body length, with very short and almost transparent fine and pointed setae. Antennal segment I almost rectangle with protuberance in middle part of inner side of segment. Ant. segm. II square-shaped. Ant. segm. III slightly wider at base then at apex. Ant. segm. IV shorter than ant. segm. V. Ant. segm. V slightly wider at apex with only one small, rounded rhinarium with small, fine sclerotic rosette which have irregular edge. Ant. segm. VI (Fig. 1 b) longest, with very long terminal process (VIb), 13.32–14.22 times base (VIa). VIa with one rounded rhinarium with small, fine sclerotic rosette which have irregular edge and five accesory rhinaria. Other antennal ratios: VIb:III 2.30–2.78, V:III 0.76–0.84, IV:III 0.59–0.78. Antennal chaetotaxy: segm. I with 6–7 setae, segm. II with 3 setae, segm. III with 12–14 setae, segm. IV with 4–6 setae, segm. V with 4–5 setae. Ant. segm. VI with 1–2 basal, 2 apical and 2 subapical setae. Antennal setae 0.007–0.01 mm long; the longest antennal seta III 3.0 times shorter than basal articular diameter of this segment. Rostrum short, reaching mesosternum, apical segment of rostrum (ARS) blunt, with 4 primary and 4 accessory setae and flat apical part (Fig. 1 d). ARS 0.14–0.15 times ant. segm. III and 0,77 times segment II of hind tarsus (HT II). Fore femur flared apically. Hind tibiae (Fig. 1 e) slightly swollen in the middle, with transverse rows of fine, short spinules, and 31–38 circular pseudosensoriae located in 1–2 rows on the almost whole length of hind tibiae; first tarsal chaetotaxy 5:5:5, empodial hairs spatulate (Fig. 1 f). Abdomen without sclerites and dorsal tubercles. Dorsal chaetotaxy: setae arranged in transverse rows on each abdominal segment, pale; on abd. segm. I–V forked (Fig. 1 i), 0.06–0.09 mm long, on abd. segm. VI–VII pointed (Fig. 1 j), 0.11–0.12 mm long. Siphunculi pale, truncate at the base and gradually narrowing towards apex with flange weak and inconspicuous (Fig. 1 h). Cauda knobbed, slightly constricted near base, with 8–9 pointed setae (Fig. 1 g). Subgenital plate poorly developed, slightly wider than longer.
Alate male (Table 2). Color of live specimens unknown; mounted specimens yellowish with head, thorax and genitalia dusky. Antennae pale with ant. segm. I dusky. Body elongate. Head (Fig. 2 a) with big compound eyes, triommatidia and well-developed ocelli. Head width 6.17–6.88 times length of antennae. Frons slightly recessed with well-developed, smooth and diverging antennal tubercles. Head chaetotaxy: dorsal side with three pairs of fronto-orbital setae, one pair of latero-dorsal setae and one pair postero-dorsal setae; ventral side with five pairs of setae. Antennae 6-segmented, 1.73–2.22 body length with very short, almost transparent and pointed setae and numerous rhinaria. Antennal segment I almost rectangle with small protuberance in middle part of inner side of segment. Ant. segm. II square-shaped. Ant. segm. III (Fig. 2 b) widest in middle part than at base and at apex. Ant. segm. IV almost as long as ant. segm. V. Ant. segm. VI longest with rounded and ciliated primary rhinarium and 4– 5 ciliated accessory rhinaria, loosely aggregated and forming irregular row. Two extremes are larger in diameter and apical one is located further from primary rhinarium (Fig. 2 b). VIb 11.5–13.0 times VIa; other antennal ratios: VIb:III 1.76–1.91, V:III 0.54–0.65, IV:III 0.59–0.67. Antennal chaetotaxy: segm. I with 7–9 setae, segm. II with 3– 4 setae, segm. III with 10–20 setae, segm. IV with 4–10 setae, segm V with 2–3 setae. Segm. VI with 2 basal, 3 apical and 2 subapical setae. Antennal setae 0.007–0.01 mm long; the longest antennal seta III about 3 times shorter than basal articular diameter of this segment. Segment III with 45–54, segm. IV with 20–29, segm. V with 14–20 oval and ciliated rhinaria (Fig. 2 c). Rostrum short, reaching second coxae. ARS short and blunt, with 4 primary and 4 accesory setae (Fig. 2 d). ARS 0.08–0.11 times ant. segm. III and 0.66–0.87 times HT II. Fore femur flared apically. Tibiae with transverse rows of short spinules and 2-3 rastral spines on the distal part. First tarsal chaetotaxy 5:5:5, empodial hairs spatulate (Fig. 2 e). Fore wings typical, with normal venation; radius strongly curved, media with 3 branches, pterostigma pale. Abdomen without sclerites, and usually without dorsal tubercles (1 specimen with very small broadly rounded, paired dorsal tubercles on abd. segm. II and III). Dorsal chaetotaxy: setae arranged in transverse rows, pale, pointed, about 0.01 mm long. Siphunculi pale, truncate at base and gradually narrowing toward apex with flange weak and inconspicuous (Fig. 2 f). Cauda knobbed, slightly constricted near base, with 4 long and pointed setae (Fig. 2 g). Genitalia well developed, strongly sclerotized with lobate parameres and elongated, hooked-shaped basal part of phallus (Fig. 2 h).
Material examined. USA: Illinois, Glencoe, 2.ix.1909, paratype, winged viviparous female from Acer saccharum, Davis, B.M. 1930 -204; Maine, Orono, 9.xi.1976, 2 oviparous females, 4 males, (Rem. & Latge), MNHN (EH) 16378-16383; North Carolina, Raleigh, Umstead PK, 10. xi.1962, 1 oviparous female, 1 male, (C.F. Smith) BMNH 682-492.
Additional material examined. Nine winged viviparous females of S. minutum; about 80 winged viviparous females of all species Drepanaphis, also 18 oviparous females and 32 males of Drepanaphis species (MNHN and BMNH).
description: Published as part of Wieczorek, Karina, Kanturski, Mariusz & Junkiert, Łukasz, 2013, Shenahweum minutum (Hemiptera, Aphidoidea: Drepanosiphinae) — taxonomic position and description of sexuales, pp. 324-330 in Zootaxa 3731 (3) on pages 324-327, DOI: 10.11646/zootaxa.3731.3.2, http://zenodo.org/record/219696