Panesthia juncta, Rose Nathan Lo, 2025

Panesthia juncta sp. nov.

Etymology: From the Latin word for ‘joined’, referring to the fusion of the tegmen with the mesonotum.

Diagnosis: Tegmina reduced to lateral sclerotised pads, wings absent; cerci broadly rounded and dorsoapically setose; tergite 5 (T5) with minute anterolateral pit; male pronotum with welldeveloped disc tubercles. In most individuals, apex of tegmina fused with lateral margin of mesonotum.

Male: Head concealed below pronotum, vertex non-foveolate; dorsal surface glabrous, with frons weakly punctuate and gently wrinkled; ocelli oblique; interocular distance greater than between mesal margins of antennal pits ( Fig. 2 View Figure 2 ).

Pronotum convex, widest between laterocaudal corners ( Fig. 3A View Figure 3 ). Anterior margin incrassate, upturned, subtruncate, swollen laterally; medially with reflexed, raised triangular tubercle, apex bluntly rounded. Pronotum anteromedially depressed, roughened, with pair of oblique, arcuate grooves running to anterolateral margins; remainder punctate, punctures very fine posteriorly; posterior pair of round, blunt disc tubercles. Lateral margins incrassate. Posterior margin slightly concave behind each laterocaudal corner. Tegmina reduced to lateral, triangular sclerotised lobes; apex typically fused with mesonotum, or rarely free and extending to before, at, or slightly after hind margin of mesonotum, apex rounded or abruptly truncate; costal margin incrassate ( Fig. 3B–C, E–F View Figure 3 ). Wings absent, relic of interstice between wing and metanotum sometimes remaining as minute sulcus behind anterior margin of metanotum. Meso- and metanotum subrectangular; laterocaudal corners rounded and slightly expanded; hind margin weakly convex; surface with irregular, fine punctuations. Coxae and femora dorsoventrally flattened, surface glabrous except for fringing setae along anterior and posterior margins; tibiae narrow, spatulate. Anterior ventral margin of front femur with 2 (rarely 0, 1 or 3) basal spines and small distal spine, posterior margin with large distal spine; anterior spines occasionally located asymmetrically.

Tergites rectangular, non-setose, punctate, punctures increasing in size and density laterally and caudally. T5–7 with anterolateral holes, weakly developed on T5 ( Fig. 3D View Figure 3 ); T6–7 holes extending as uneven grooves behind anterior margin of tergite, diminishing medially, margin undulate above the grooves. T7 lateral margin posteriorly somewhat concave, laterocaudal angle produced into an acute spine; hind margin straight. Hind margin of supra-anal plate weakly undulate with 7 (rarely 6 or 8) shallow, rounded denticles; lateral angles obtuse and broadly rounded, oblique, larger than denticles. Sternites 1–4 weakly punctate laterally; S5–6 weakly punctate mesally and densely punctate laterally. S7 densely punctate; depressed laterally with shallow, transverse groove in anterolateral corner; posterior margin truncate or weakly concave, exposing subgenital plate, margin somewhat incrassate below cerci. Cerci bulbous, anterolaterally concave; dorsal surface basally glabrous and apically with few, fine setae; ventral surface covered by dense short setae, with few longer setae. All four genital phallomeres present and well developed ( Fig. 4A– C View Figure 4 ); L1 weakly sclerotised, consisting of two ovoid lobes, more heavily sclerotised in cleft between lobes; L2vm elongate, rod-like, apically bulbous; L2d approximately triangular, apex rounded and heavily sclerotised, lateral margins variably concave, length approximately equal to length at base; R2 strongly sclerotised, hook-shaped.

Size: Total length 33.1 (34.0–36.4); pronotal length × width, 7.4 × 11.1 (8.5–9.0 × 12.2–13.0) ( n = 2).

Colour: Head black or dark brown, eyes dark, ocelli pale. Antennae dark brown basally, grading to tan distally. Clypeus fulvous, labrum pale dorsally and brown ventrally, mandibles brown. Labial and maxillary palpomeres brown or tan, with yellow ring around apical circumference. Pronotum dark brown to black anteromedially, fuscous laterally and posteriorly; meso- and metanotum fuscous to dark brown. Coxae and femora ferruginous to dark brown; tibiae dark brown to black, spines black apically; tarsomeres ferruginous, pulvilli tan. Tergites fuscous to black. Abdominal sternites 1–6 ferruginous mesally and black laterally; cerci ferruginous to black, with pale setae. Dorsal and ventral surfaces lustrous; ventrally with sparse golden setae. Subgenital plate fuscous to dark brown, posterior margin paler.

Female: Pronotum without anterior development, disc less granular and more shallowly depressed, disc tubercles absent, with or without shallow pits in their place. Abdomen broader; hind margin of S7 entire; subgenital plate absent. An   GoogleMaps ootheca was dissected from one female ( Dryander Forest   GoogleMaps , Queensland, 20.2751°S 148.5860°E), and consisted of 22 eggs arranged in a double row.

Size: Total length 29.4–35.2; pronotal length × width, 6.8–7.8 × 10.4–11.1 ( n = 2).

Nymph: Male pronotum without anterior development; tegmina absent; early instars ferruginous dorsally and fulvous ventrally; late instars ferruginous to black dorsally, fulvous or reddish ventrally.

Material examined: Holotype ♂: QM T260326, QLD Dryander Forest , 15 km NNE of Proserpine, 20.2751°S 148.5860°E, 80 m, in rotten log, 6.v.2015, BG, HAR, JAW. GoogleMaps

Paratypes (4): ANIC: 1♂ (ANIC 09-006304), GoogleMaps 1♀ ( ANIC 09-006305), QLD Brandy Creek , 8 km SW of Airlie Beach, 20.341°S 148.682°E, 165 m, in rotten log, 5.v.2015, BG, HAR, JAW. QM: GoogleMaps 1♂ (T260327), GoogleMaps 1♀ (T260328), same data as holotype GoogleMaps .

Other material (176): HARPC: 3♂, 3♀, 2♂ nymphs, 3♀ nymphs, same data as holotype; 3♀, 1♂ nymph, 4♀ nymphs, QLD 12 km W of Airlie Beach, off Patullo Road   GoogleMaps , 20.2707°S 148.5822°E, 13.viii.2014, HAR, JRW; 1♀, 3♂ nymphs, 3♀ nymphs, QLD 7.3 km SSW of Airlie Beach, Brandy Creek Road   GoogleMaps 20.34103°S 148.6816°E, 12.viii.2014, HAR, JRW; 1♂, 2♀, 11♂ nymphs, 11♀ nymphs, QLD 7.3 km SSW of Airlie Beach, Brandy Creek Road   GoogleMaps 20.3411°S 148.6785°E, 14.viii.2014, HAR, JRW; 3♀, 2♂ nymphs, 1♀ nymph, same data as ANIC paratypes. JAWPC: 4♂, 6♀, 42♂ nymphs, 44♀ nymphs, same data as holotype; 5♀ nymphs, QLD 12 km W of Airlie Beach, off Patullo Road   GoogleMaps , 20.2707°S 148.5822°E, 13.viii.2014, HAR, JRW; 10♂ nymphs, 6♀ nymphs, QLD 7.3 km SSW of Airlie Beach, Brandy Creek Road   GoogleMaps , 20.34103°S 148.6816°E, 12.viii.2014, HAR, JRW, HARPC. QM: 1♂, 1♀, QLD Mt Dryander   GoogleMaps , 20.25°S 148.55°E, 650 m, 21.xi.1992 – iv.1993, DC, GBM.

Distribution and remarks: This species is presently known from wet forest in the vicinity of Airlie Beach, Queensland. This habitat is characterised by high rainfall (~ 1800 mm p.a.) and relatively organic-rich soils ( Hardy, 2003). Typical of the genus, P. juncta constructs resident galleries in decaying logs, and has been observed to form aggregations of approximately 5–10 individuals. While all specimens collected by the authors were from forest immediately adjoining National Park or State Forest, we expect this species to also be present within those reserves.

The fusion between the mesonotum and the tegmen observed in P. juncta is unique among all known panesthiine taxa. Similar, but not identical, wing structure has been observed in Panesthia tryoni tegminifera ( Roth, 1977) , as well as Ancaudellia insularis ( Kirby, 1903) . In these taxa, the tegmina and hind wings, respectively, are partially fused with the mesonotum along the entire length of the mesal margin, with a suture that incompletely cleaves the cuticle. In contrast, only the apex of the tegmen is fused in P. juncta , with most of the mesal margin completely detached. Interestingly, the extent of fusion varies intraspecifically: in some specimens examined, the apex of the tegmen is completely contiguous with the mesonotum; while in others there is only a thin (< 1 mm diameter) bridge of connecting integument. Additionally, in a minority of examined material (<10%), one or both tegmina were completely free.