Panaetius laevicornis sp. nov.

Figures 1, 3, 6, 7, 8, 9, 11, 12

Zoobank registration: http://zoobank.org/urn:lsid:zoobank.org:act:5EF8D1E6-F5DC-47ED-AAB6-CF0F0ACB2036

Holotype: ♂, AUSTRALIA: New South Wales: Comboyne, 10 XI 1932, K. C. McKeown (00002771) (AM) .

Paratypes: AUSTRALIA: Queensland: 2♀♀, National Park, Nov 1920, H. Hacker (00002778–00002779) (QM) ; 2♂♂, Mt. Tambourine, 29 Nov 1925, H. Hacker (00002774) (QM) ; 1♀, National Park, Macpherson Range, 1928, H. J. Carter (00002773) (AM) ; 1♀, Stanthorpe, 01 I 1928, H. J. Carter (00002772) (AM) ; 1♂, National Park, 01 Jun 1929, (00002776) (QM) ; 1♂, Petrie, 16 Nov 1962, G. Monteith (00002775) (QM) ; 1♀, Palmerston National Park, via Innisfail, 23–24 Apr 1968, B. Cantrell (00002780) (QM) ; 2♀♀, Basset site. Mt. Glorious, Argyrodendron actinophyllum ( Malvaceae), Jan 1988, Y. Basset (00002777) (QM) .

Diagnosis. Panaetius laevicornis sp. nov. is recognised by the following combination of characters: male eyes pink; female eyes yellow (Fig. 1); anterior margin of head concave medially (Fig. 7a); anterolateral processes of pronotum triangular (Fig. 7b); humeral horns projected anterolaterally, apically undivided, without ridges (Figs 1,7b); MTG peritreme anterolaterally oriented, mesepimeron with evaporative area (Fig. 8a).

Description. Male. COLOURATION. Head: yellowish brown, with dark brown markings dorsally; anterior region of paraclypei pale brown. Eyes: pink, with medial and posterior margins dark brown, almost black. Antennae: AI-AII(b) pale brown, except apex of AII(b) weakly medium brown; AIII-AIV medium brown, with apex of AIV dark brown. Labium: mostly medium brown; LIV darker brown, almost black.

Pronotum: yellowish brown, with dark brown markings; callus dark brown; humeral horns reddish brown, with anterior and posterior margins black, with pale brown stripe medially on humeral horns; anterolateral processes pale brown. Scutellum: lateral margins yellowish brown, medial region dark brown, V-shaped pale brown callose marking at apex. Thoracic pleura: uniformly dark brown, with black markings. MTG: external efferent system yellowish brown. Hemelytra: pale brown, with medium brown stripe along medial fracture; membrane medium brown, with two indistinct brown spots.

Legs: uniformly pale brown, with apex of tarsi medium brown, claws dark brown, almost black. Abdomen: yellowish brown, with dark brown stripes laterally; abdominal spine yellowish brown. Pronotum: white decumbent setae on lateral margins and humeral horns. Legs: uniformly pale brown; setae on femora sparse; tibiae and tarsi mostly dense, with bristlelike setae and apex of tarsi with a few hairlike setae. Abdomen: with moderate distribution of semierect setae. STRUCTURE.

Head: paraclypei arcuate, apically contiguous, with lateral margins weakly reflexed. Antennae: AIII-AIV slightly wider than other segments; AI shortest, not surpassing anterior margin of head; AII(a) second longest segment, ca. 0.5× longer than AI; AII(b) a little longer than AI, and shorter than AIII; AIV longest segment, ca. 1.5× longer than AII(b). Labium: extending just beyond procoxae, not reaching mesocoxae.

Pronotum: anterolateral processes of pronotum triangular; humeral horns distinctly protruding, projecting anteriorly; humeral horns smooth, without ridges or teeth, with vertex slightly downward; dorsum medially transverse concave.

Scutellum: flat, slightly longer than wide. MTG: external efferent system mostly as in genus description; peritreme posterolaterally oriented; mesepimeron with evaporative area (Fig. 8b). Legs: tarsi narrow, tarsal segment I short, segment II ca. 1.5–2.0× longer than segment I. Male genitalia (Fig. 3): pygophore with two prominent lateral spines on ventral rim of genital opening, with dense long hairlike setae medially; parameres slender, slightly arcuate medially; aedeagus with a pair of sclerotised dorsal processes, with ventral conjunctival lobe distally divided; vesica membranous.

Female. COLOURATION. Mostly as in male, aside from following differences. Head: uniformly yellowish brown, anterior region with slightly reddish tinge. Eyes: pale brown, shining, sometimes anterior or medial region with slightly reddish tinge. Antennae: AIV-AV pale reddish brown. Labium: pale brown; LIV dark brown. Pronotum: callus reddish brown. Scutellum: medial region reddish brown, V-shaped medium brown callose stripe at apex. Legs: uniformly pale brown, with apex of claw black. Abdomen: Pendergrast’s organs yellowish brown. STRUCTURE. Mostly as in male. Labium: nearly reaching mesocoxae. Pronotum: humeral horns longer. Abdomen: Pendergrast’s organs (Fig. 9b). Female genitalia: capsula seminalis small and recurved (Fig. 6b); thickenings of vaginal intima cloud-shaped (Fig. 6b); two sclerotised rings long and thin, contiguous medially, with lateral and medial region of sclerotised rings elevated (Fig. 6b).

Measurements. Table 2.

Etymology. From the Latin laevicornis meaning ‘smooth horns’, in reference to the lack of prominent ridges or teeth on the humeral horns.

Distribution. Distributed in coastal New South Wales and Queensland (Fig. 11).

Plant associations. Two specimens of this species were collected on Argyrodendron actinophyllum ( Malvaceae), and based on the ‘>10 specimens’ criterion, we do not hypothesise it as a host plant. It is noteworthy, however, that P. trabifer was also collected on this plant species.

Remarks. Panaetius laevicornis can be separated from other members of the genus by its humeral horns directed anteriorly, which are undivided, smooth and devoid of ridges (Fig. 1), and the anterolateral processes of the pronotum are triangular (Fig. 7b).