Aacanthocnema Tuthill and Taylor
Creators: name: Taylor, Gary S.
name: Jennings, John T.
name: Purcell, Matthew F.
name: Austin, Andy D.
Publisher: name: Zenodo
Year: 2011
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hemiptera
Triozidae
Aacanthocnema

description: Aacanthocnema Tuthill and Taylor
Aacanthocnema Tuthill & Taylor, 1955: 252 –3. Type species: Trioza casuarinae Froggatt 1901, by original designation.
Redescription. Adult. General colour pale ochraceous to dark brown with light orange-brown to black markings; vertex with orange-brown to dark brown marking in vicinity of fovea and often a transverse dark stripe on anterior margin; genal processes white to pale brown; antennae pale ochraceous to brown, progressively dark brown to black towards apex; pronotum, mesonotum, mesopraescutum and metascutum pale ochraceous to brown with pale orange-brown to black markings; fore wings clear or with brown infuscation along some wing veins; abdominal tergites brown to black; male terminalia ochraceous to black; female terminalia pale ochraceous with brown to black markings.
Structure: antennae short, 0.7–1.3 mm in length, 0.9–1.8 times width of head, 10-segmented, a single subapical rhinarium on each of segments 4, 6 and 9; segment 3 short, 0.2–0.5 mm; segment 10 with 1 long, pointed and 1 short, truncate apical setae; genal processes elongate with rounded apices 0.15–0.25 mm long, about 0.6–0.9 times length of vertex, slightly divergent distally, little declined ca. 40° to longitudinal axis of vertex, ca. 80° to longitudinal axis of body; anterior margin of vertex delineated by moderate ridge, overhanging median ocellus and genal processes; vertex short, broad, 0.4–0.7 times longer than wide with prominent medial suture and prominent fovea; occipital margin sharply defined; head wider than pronotum and mesoscutum; pronotum short, broad with prominent anterior, medial node; thorax rather flat dorsally; fore wings elongate-oval, 2.5–3.1 times longer than wide with broadly rounded to pointed apex, usually clear but sometimes with brown infuscation along some wing veins; Rs very short, terminating well short of wing apex; vein m1+2 terminating little anterior of wing apex; M branch on or distal to Rs-Cu1a line; cells m1 and cu1 short, broad (m1 cell value 0.7–1.4, cu1 cell value 0.7–1.7); radular areas elongate triangular at margin of wing in cells m2 and cu1 not always in m1 but if so often much reduced; meracanthus conical, pointed; apical hind tibia without spurs, but with corona of 6–10 setae; hind tarsi without spurs; hind tibia with basal genual node. Male proctiger unipartite, short, without lateral expansions; subgenital plate of male short, rounded; parameres thin, elongate, curved inward towards apex. Female proctiger short, 0.26– 0.40 mm in length, 0.3–0.6 times width of head, broadly rounded, ovipositor short, stout and straight, subgenital plate short, narrow, broadly rounded from lateral aspect.
Nymph (Figs 13, 26–28, 36, 58–59) elongate-narrow, heavily sclerotised, scale-like; body about 1.8–2.6 times longer than wide; antennae short; cephalothorax entire, with a single prominent depression on each of meso- and metathoracic tergites; fore wing pads produced anteriorly, confluent with lateral margin of head; abdominal tergites fused to form caudal plate; caudal plate elongate, narrow, about 0.8–1.2 times longer than wide; circum-anal pore field ventral and distant from posterior margin of abdomen; sectasetae very short, truncate on margin of head, fore and hind wing margins, and margin of caudal plate; dorsum without sectasetae.
Diagnosis. Species of Aacanthocnema can be distinguished from all other triozids by the following combination of characters: antennae short, 0.8–1.8 times width of head, with single rhinarium present subapically on segments 4, 6 and 9, genal processes long, conical, 0.6–0.8 times length of vertex, produced ventrally and delineated from vertex by a prominent overhanging ridge, apex of fore wings broadly rounded, wings clear, sometimes with brown infuscation along wing veins, vein Rs short, medial and cubital cells short, broad, hind tibia without spurs but with a corona of 6–8 setae, male proctiger short, without lateral expansions, parameres simple, female proctiger short, broadly rounded with a rounded apex, nymphs elongate-narrow, heavily sclerotised and scale-like. It differs from Acanthocasuarina in the arrangement of antennal rhinaria (rhinarium absent on segment 8 in Aacanthocnema), status of spurs on apical hind tibia (absent in Aacanthocnema), shape of the female proctiger (short, rounded in Aacanthocnema, short, with an apical hook in Acanthocasuarina) and shape of the ovipositor (short, stout and straight in Acacanthocnema, long, thin and either straight or curved upward in Acanthocasuarina).
description: Published as part of Taylor, Gary S., Jennings, John T., Purcell, Matthew F. & Austin, Andy D., 2011, A new genus and ten new species of jumping plant lice (Hemiptera: Triozidae) from Allocasuarina (Casuarinaceae) in Australia, pp. 1-45 in Zootaxa 3009 on pages 5-6, DOI: 10.5281/zenodo.278552