Casuarinicola Taylor

Taylor, Gary S., Austin, Andy D., Jennings, John T., Purcell, Matthew F. & Wheeler, Gregory S., 2010, Casuarinicola, a new genus of jumping plant lice (Hemiptera: Triozidae) from Casuarina (Casuarinaceae), Zootaxa 2601, pp. 1-27 : 3-4

Casuarinicola Taylor , gen. nov.

Type species: Casuarinicola australis Taylor sp. nov.

Description. Adult. General colour pale ochraceous to brown with light orange-brown to black markings; vertex with dark marking in vicinity of fovea and medial suture; antenna pale ochraceous to brown, progressively dark brown to black towards apex; pronotum, mesonotum, mesopraescutum and metascutum pale ochraceous to brown with light orange-brown to dark brown markings; fore wings with dark markings (in females of most species) or clear (in males of most species); abdominal tergites pale brown to black; male terminalia ochraceous to black; female terminalia pale ochraceous with brown to black markings.

Structure: antenna short, 0.6–0.9 mm in length, 1.1–1.5 times width of head, 10-segmented, a single subapical rhinarium on each of segments 4, 6, 8 and 9; first antennal flagellum (antennal segment 3) short, 0.18–0.25 mm; segment 10 with 1 long, pointed and 1 short, truncate apical setae; genal processes short, 0.04–0.14 mm, 0.2–0.5 times length of vertex, conical, little declined ca. 10–20° to longitudinal axis of vertex, ca. 30–40° to longitudinal axis of body; anterior margin of vertex delineated by moderate ridge; vertex short, 0.6–0.9 times longer than wide with prominent medial suture and prominent fovea; pronotum visible from above with a weak to prominent anterior medial node; thorax moderately arched, head little wider than pronotum, about same width as mesoscutum, fore wing elongate-oval with broadly rounded to subangular apex and mottled with dark markings (in females of most species) or clear (in males of most species), Rs short, terminating well short of wing apex; vein M1+2 terminating little anterior of wing apex; M branch variable with respect to Rs-Cu1a line, generally branching on or proximal to Rs-Cu1a line in females and on or distal in males; cell m1 short, broad (m1 cell value 1.1–1.8) to acute triangular (m1 cell value 1.8–2.2); cell cu1 elongate triangular (cu1 cell value 0.6–1.1) to short, broadly triangular (cu1 cell value 1.1–2.2); radular areas elongate triangular in cells m1, m2 and cu1; meracanthus conical, pointed; metatibia with basal genual node; apical metatibia with 1 outer and 2 inner spurs; basitarsus without spurs;. male proctiger unipartite, short with broad lateral expansions; subgenital plate of male short, rounded; parameres thin, elongate, curved inward towards apex; distal segment of aedeagus strongly curved basally; distal segment of aedeagus angled mid-length, with a slightly swollen apex; female proctiger broadly rounded from lateral aspect, short, 0.4–0.6 mm in length, 0.75–0.95 times width of head, pointed apically and with a pair of broad, flange-shaped lateral lobes; subgenital plate short, narrow, broadly triangular from lateral aspect; ovipositor valves thin, needlelike, weakly recurved towards apices.

Final instar nymph. Triozine in type; dorsal surface outline broadly ovate; body about 1.3–1.6 times longer than wide; antenna with 4 flagellomeres; cephalothorax entire; fore wing pad about 1.0– 1.2 mm long, produced anteriorly to anterior margin of eye; abdominal tergites fused to form caudal plate; caudal plate short, broad, about 0.8–0.9 times longer than wide; circum-anal pore field ventral and distant from posterior margin of abdomen; sectasetae short, truncate and closely and evenly spaced on anterior margin of head, fore and hind wing margins, and margins of caudal plate; dorsum without sectasetae.

Diagnosis. Species of Casuarinicola can be distinguished from all other triozids by the following combination of characters: antenna short, 1.1–1.5 times width of head, genal processes short, conical, 0.2–0.5 times length of vertex, fore wing with broadly rounded to subangular apex, mottled with dark markings (in females of most species) or clear (in males of most species), male proctiger short, with broad lateral expansions, parameres simple, female proctiger short, broadly rounded, pointed apically and with a pair of broad, flange-shaped lateral lobes. It differs from Aacanthocnema , the only other genus described from the Casuarinaceae , by: orientation of genal processes being little-declined vs well-declined to longitudinal axis of body; antennae with rhinaria on segments 4, 6, 8 and 9 vs 4, 6 and 9; metatibia with 1 outer and 2 inner spurs vs metatibia lacking spurs, but with a corona of apical setae; shape of male parameres simple, little curved to apex vs short, sickle-shaped and strongly curved inwards to apex; shape of female proctiger being short with a pair of lateral lobes vs short, bluntly rounded, without lateral lobes; nymphs broadly ovate, little-sclerotised, typically ‘triozine’ in type vs elongate, heavily sclerotised and ‘scale-like’; and host, recorded only from Casuarina vs only from Allocasuarina .

Etymology. From the host genus, Casuarina , + suffix - cola (Latin); dweller, inhabitant.