Acizzia veski, Taylor, Gary S. & Moir, Melinda L., 2009

Taylor, Gary S. & Moir, Melinda L., 2009, In threat of co-extinction: two new species of Acizzia Heslop-Harrison (Hemiptera: Psyllidae) from vulnerable species of Acacia and Pultenaea, Zootaxa 2249, pp. 20-32 : 21-26

Acizzia veski , sp. nov.

( Figs 1–10 ; Tables 1 –7)

Types. AUSTRALIA, Western Australia: Holotype: 1 3 (slide), Stirling Range NP, Mt Talyuberlup, 351 m., 34°24.843’S, 117°57.440’E, M.L. Moir & K.E.C. Brennan, 17.x.2007, ex Acacia veronica (WAM T71980). Paratypes: 2 3, 2 Ƥ (slide), same data as holotype (WAM T71981-T71984); 1 3, 2 Ƥ (slide), 6 3, 6 Ƥ (dried, on 4 points), same data (WINC 030550 - 030556); 3 nymphs (1 slide), same data, except 18.x.2007 (WINC 030557); 1 3, 1 Ƥ, 7 nymphs (dried, on 2 points), same data (WAM T71985-71993); 9 3, 10 Ƥ, 2 nymphs (dried, on 11 points), same data (AgWA); 12 3, 16 Ƥ, 4 nymphs (dried, on 11 points), same data (MLM 00806-00837).

Description. Adult. Head, habitus and wing as in Figs 1–6 . Colouration: General colour ochraceous with brown to dark brown markings (female slightly more reddish-brown than male). Head and thorax ochraceous with brown to dark brown markings; vertex ochraceous with medial brown spot in posterior half confluent with medial suture and 2+2 submedial brown markings in vicinity of foveae; genal processes ochraceous with brown infuscation at apex; antennal segments 1–2 ochraceous to brown; segment 3 ochraceous with brown apex; segments 4–8 with progressively darker apices; segments 9–10 dark brown to black; pronotum ochraceous with thin brown medial longitudinal stripe, 1+1 brown submedial longitudinal stripe, 1+1 brown mediolateral spot and 1+1 sublateral longitudinal stripe; mesopraescutum ochraceous with 1+1 broad triangular brown markings anteriorly, and darker anteriorly and laterally; mesoscutum ochraceous with thin medial longitudinal strip and 2+2 light brown longitudinal submedial stripes; mesoscutellum ochraceous with medial orange-brown infuscation; abdominal tergites and sternites dark brown to black; meracanthus pale ochraceous; femora dark ochraceous with dorsal dark brown longitudinal infuscation; fore and mid tibia brown, hind tibia ochraceous to brown; tarsi ochraceous; apices of distal segments of tarsi with brown infuscation; forewings heavily pigmented with dark brown to black maculation darker and denser in anteroapical quadrant, darker and sparser in antero-basal quadrant, and paler and sparser in posterior (lower) half; wing veins dark brown in anterior half (Rs, M, M1+2), ochraceous in posterior half (M3+4, Cu, Cu1a, Cu1b). Male proctiger dark brown to black with base of apical portion and posterior apices of lateral lobes pale ochraceous; subgenital plate glossy dark brown to black; parameres pale ochraceous. Female proctiger and subgenital plate dark brown to black.

Structure: Antenna long, 2.3–2.6 times width of head, 10-segmented, a single subapical rhinarium on each of segments 4, 6, 8 and 9; segment 10 with 2 long, pointed apical setae; genal processes moderate in length, broadly rounded, in same plane as longitudinal axis of vertex, little deflexed, ca. 20° to longitudinal axis of body, delineated from anterior margin of vertex by moderate suture; vertex with medial suture and prominent fovea, anterior margin produced to form distinct anterior lobes (adjacent to medial suture), medially produced to form a lobe between medial suture and foveae, and posteriolaterally produced to form a lobe to support lateral ocelli; pronotum short, broad, with hind margin little recurved; thorax moderately arched, head wider than pronotum, little wider than mesoscutum; forewing ovate with broadly rounded apex; Rs moderate in length, terminating little anterior of wing apex; vein m1+2 terminating well posterior to wing apex; cell m1 elongate, triangular; cell cu1 elongate triangular, strongly recurved towards wing base; radular areas short broad triangular in cells m1, m2 and cu1; meracanthus conical, pointed; apical metatibia with 1 outer and 3 inner spurs, basitarsus with a pair of apical spurs. Male terminalia as in Figs 7–8 ; proctiger with thin, reclinate apical node and broadly-rounded lateral (posterior) lobes each with a thin terminal distal appendage; parameres broad, blade-like, evenly curved inward towards apex; inner face of parameres with rod-shaped setae; apical segment of aedeagus with an asymmetric bulbous apex with an anterior hook. Female terminalia as in Fig. 9 ; proctiger short, broadly rhomboid from lateral aspect; subgenital plate short, broadly triangular from lateral aspect.

Nymph. Habitus as in Fig. 10 . Cephalothoracic plate glossy dark brown; eyes reddish-brown; antenna yellow brown, progressively darker to black at apex; thoracic sclerites brown; fore and hindwing pads glossy brown with glossy black lateral margins; first 4+4 free abdominal sclerites glossy dark brown to black; caudal plate glossy dark brown. Antenna with a short capitate seta (about as long as width of antennal segments) on each of segments 4 and 6; a single rhinarium on each of antennal segments 4, 6, 8 and 9; apex of antenna with 2 pointed setae; 4–5 capitate setae on lateral margin of forewing pad and 2 capitate setae on apex of hindwing pad; 4–5 capitate setae on lateral margins of caudal plate; first two abdominal sternal sclerites with a single lateral capitate seta, remaining sclerites with pointed setae; circumanal pore ring in ventral position, with a single row of pores.

Measurements in mm; mean ± standard deviation; range.

Species Sex n BL (vertex BL (vertex to HW GCL VL VW AL AF1L

to apex of

terminalia) folded wings)

Measurements in mm; mean ± standard deviation; range.

Species Sex n WL WW Ve i n R s Vein M stem Vein M1 + 2 Marginal Marginal Vein Cu 1 b

width cell width cell

m1 Cu1

Comments. Acizzia veski is the first species of Acizzia to be described from Western Australia, and is considered endemic to that State. Only three other species have been recorded from Western Australia; A. acaciaedecurrentis (on A. cyclops: Van Der Berg 1980 ), A. acaciaebaileyanae and A. uncatoides ( Hollis 2004) . However, these species of Acizzia may be native to eastern Australia, and introduced in Western Australia, as they have been in other regions of the world (see Hollis 2004).

Acizzia veski sp. n. can be distinguished from all other described species of Acizzia by the following suite of characters: antenna long, 2.3–2.6 times width of head ( Fig. 1 ); genal processes moderate in length, 0.55– 0.66 times length of vertex, with broadly rounded apices ( Fig. 1 ); both sexes with characteristically mottled wings ( Figs 2–6 ); male proctiger with thin, reclinate apical node and broadly-rounded lateral (posterior) lobes each with a thin terminal distal appendage ( Fig. 7 ); apical segment of aedeagus with an asymmetric bulbous apex with an anterior hook ( Fig. 7 ); inner face of parameres with rod-shaped setae ( Fig. 8 ); female terminalia short, proctiger broadly rhomboid, and subgenital plate broadly triangular from lateral aspect ( Fig. 9 ).

Etymology. Named in honour of Dr Peter Vesk, who has provided financial, logistical and intellectual support for the investigation into co-extinction of Australian insects on plants that resulted in the discovery of this new species.

Host-plant association. The plant genus Acacia is host to a number of described species and many undescribed species of Acizzia ( Yen 2002) . The genus Acacia is widely distributed with over 1350 species world-wide, however, recent work suggests that Acacia comprises several genera (Maslin et al. 2003; Orchard & Maslin 2003). Within Australia there are 948 species of Acacia in the subgenus Phyllodineae distributed in all states and territories and adapted to many different habitats (e.g., see http://www.anbg.gov.au/cpbr/ taxonomy/acacia-conserved-2004.html). Acacia veronica is a small, often spindly, tree (1.5– 7 m) restricted mainly to watercourses in the Stirling Ranges of Western Australia, with smaller individuals growing at higher altitudes, and is often associated with marri ( Corymbia calophylla ) woodlands. It is listed for ‘Priority 3’ conservation because of its restricted distribution, however, key threatening processes most likely include climate change ( Barrett et al. 2008), inappropriate fire regime and habitat clearing. The closest relatives of Acacia veronica appear to be eastern state species ( Maslin 1989; Maslin pers. comm. 2008). One of us (MLM) searched for known populations of A. veronica to sample for insects, which resulted in five populations of the plant rediscovered, four previously recorded populations found to be extinct, and a newly discovered population located. However, of the six populations of A. veronica sampled, only one yielded A. veski , suggesting that although the host has a low ‘priority 3’ conservation status, the psyllid is critically endangered (Moir et al., in press). No other host associations have been previously recorded, however, a diverse assemblage of insects was collected from A. veronica during sampling, including at least one weevil and chrysomelid beetle that may also be restricted to A. veronica (Moir, unpublished data).

Figures

FIGURES 1 – 6. Acizzia veski, sp. nov. (1), Head, male, (dorsal aspect, from slide); (2), habitus, male, (dorsal aspect); (3), habitus, female, (dorsal aspect); (4), habitus, male (lateral aspect); (5), habitus, female (lateral aspect); (6), forewing, male. Scale = 0.5 mm.

FIGURES 7 – 10. Acizzia veski, sp. nov. (7), Male terminalia (lateral aspect); (8), paramere (inner face, lateral aspect); (9), female terminalia, (lateral aspect); (10), fifth (final) instar nymph (ventral aspect, left; dorsal aspect right). Scale = 0.2 mm in Figs 7 – 9, 0.5 mm in Fig. 10.

Tables

TABLE 1. Measurements of Acizzia veski sp. n. and A. keithi sp. n. from endangered Acacia and Pultenaea.

Acizzia veski sp. n. 3	4	1.98± 0.06 1.90–2.03	3.19±0.02 3.17–3.21	0.70±0.02 0.68–0.72	0.12±0.01 0.11–0.12	0.21±0.01 0.20–0.22	0.43±0.01 0.42–0.43	1.75±0.03 1.72–1.78	0.40±0.01 0.39–0.40
Ƥ	4	2.48±0.23 2.14–2.66	3.59±0.16 3.38–3.76	0.74±0.03 0.71–0.77	0.14±0.01 0.13–0.16	0.24±0.02 0.22–0.25	0.46±0.01 0.44–0.47	1.75±0.08 1.68–1.84	0.41±0.01 0.40–0.42
Acizzia keithi sp. n. 3	1	1.38	2.00	0.54	0.05	0.19	0.33	0.65	0.12
Ƥ	4	1.82±0.08 1.76–1.93	2.35±0.07 2.28–2.45	0.59±0.01 0.58–0.60	0.05±0.01 0.05–0.06	0.20±0.01 0.19–0.22	0.36±0.01 0.35–0.37	0.62±0.02 0.60–0.63	0.10±0.01 0.10–0.11