Polydema eubenangee De Prins, Sruoga & Zwick, 2025

Polydema eubenangee De Prins, Sruoga & Zwick , sp. nov.

( Figs 481, 486, 487, 495, 496, 505, 506, 512, 515, 638)

Type locality: Australia, Queensland, Eubenangee Swamp National Park.

Type specimens: Holotype ♀: [labels verbatim] [1] Australia QLD [Queensland]/ 17.26°S 145.58°E /Eubenangee Swamp/Nat. Pk. [National Park] em.[erged]/28.Jan.[January]1997/T. & M. Kumata. [2] Host 5667/ Mallotus / polyadenos, DNA sample NULT025284, genitalia slide 6204, ANIC Acc. no 31 085541, in ANIC (Canberra).

Paratype ♀: Australia, Queensland, 17.26°S 145.58°E, Eubenangee Swamp National Park, emerged 30 January 1997, T. & M. Kumata, Host 5667, Mallotus polyadenos F.Muell. ( Euphorbiaceae ), in ANIC (Canberra).

Remark: Additional specimen with the following labels:

Queensland, 16.49°S 145.38°E, Kuranda em.[erged] 28 March 1998, T. & M. Kumata, Host 6024, Mallotus sp. , in ANIC (Canberra) GoogleMaps .

This specimen certainly belongs to the same complex of species as Polydema mallota sp. nov., P. macaranga sp. nov. P. eubenangee sp. nov., and P. virgula sp. nov. It is the only specimen belonging to a potential new species and it lacks the abdomen. The factors such as unreliable diagnosis based on external characters only due to the possible variability in the wing pattern within this complex, probable plasticity in bionomics of Mallotus feeding Polydema species-complex, not yielding enough DNA from legs (only one hind leg is present) determined our decision to abstain from describing this species as new until more material is found. We prefer to have a diagnostic character set, unconditionally separating this probable new species before it is officially named.

Type depository: Australian National Insect Collection, Canberra, Australian Capital Territory, Australia.

Diagnosis: The female genitalia characters between both species feeding on Mallotus spp. at the same locality but in slightly different periods (a month difference in mining records) are strongly diagnostic, especially the signal area on corpus bursae and the ductus bursae itself. In P. mallota sp. nov. the corpus bursae is sac-shaped, wrapped by a tape-shaped ornamental sclerotisation, ductus bursae short, but strongly sclerotised, nicely cylindrical. In P. eubenangee sp. nov. the corpus bursae is an irregular-shaped wrinkled internal structure with one huge more or less rectangular, strongly sclerotised with different dentate markings and huge melanised fold, as described below; ductus bursae in P. eubenangee sp. nov. is extremely short, does not protrude from the anterior margin of segment VII, corpus bursae is connected with very short antrum via very short ductus bursae. Though all Polydema species presented here are Euphorbiaceae feeders the host specificity and bionomics can serve well as diagnostic indicators: Polydema mallota sp. nov. feeds on Mallotus paniculatus Müll. Arg. , while P. eubenangee sp. nov. feeds on M. polyadenos F. Muell.

Description: Wingspan ca. 4.8–5.8 mm; length of the forewing 2.3–2.8 mm ( Fig. 481).

Head ( Figs 486, 487, 496): vertex smooth, ochreous, dotted with beige and darker ochreous, irregular small spots, two tufts of short piliform, rather broad, and compactly pressed scales radially directed cover the occiput. Frons light ochreous golden, with some narrow dark brown scales near eyes, labrum white. Maxillary palpus short, almost as long as scape, erect, dark ochreous. Labial palpus relatively long, ca. 2× longer than the diameter of the eye, covered with loose scales, basal palpomere golden ochreous, mid palpomere dirty white with golden ochreous base and apex, terminal palpomere white with shiny golden apex, a few narrow, prolonged ochreous scales like tiny stripes are inserted in sub-apical area of palpomere III, proboscis rolled, ochreous beige. Antenna dark ochreous, longer than forewing, flagellomeres with dark dorsal patches consisting of tiny piliform narrow stripes and light bases, antenna uniformly light ochreous ventrally, pedicel as big as the following flagellomere, also concolourous with the following flagellomere, scape dirty white, with a couple of ochreous patches laterally, with 15–20 long, light golden ochreous; hanging pecten of different lengths.

Thorax ( Figs 481, 496): thorax tegula light ochreous with white apical part. Forewing narrowly elongated, equal in width along all its length, with a gently rounded apex, ground colour ochreous with white clear and contrastive ornaments and a row of white small dots on black background running along the costal margin; dorsal margin is decorated by a series of oblique stripes of different length and of different shapes. Base of the forewing is decorated by an irregular patch-like double fascia, followed by a triangular marking at sub-base, the broader triangular or reversed Y marking is in the mid of forewing followed white-grey-black markings at sub-apical part; a peculiar, broad, interrupted, narrowing at apical end stripe at the mid of sub-apical part, apical spot indistinct, just a tiny oval spot or comma-shaped stripe, that might differ in shape even in the same specimen between right and left forewing; apical line very thin and interrupted by dirty white scales. The fringe line is clear black, gently following apical margin of forewing. Fringe grey with some silver shine, shorter at tornus the longest at subapical part and again shortening towards base of forewing. Hindwing narrow, elongate, sharply pointed, ground colour dark grey, fringe long, ca. 6× longer than the width of hindwing at the base, with the longest piliform scales hanging at the base of the dorsum of the hindwing. Fore femur and tibia dark ochreous, fore tarsomere I dark fuscous with two white spots one at base and the other at median part, tarsomere II dirty white with grey median part, tarsomeres III–IV dirty white with fuscous basal and apical parts, tarsomere V and tip of tarsus grey; mid femur fuscous, mid tibia grey at basal part, dirty white at sub-apical part and with narrow fuscous stripe at mid of white area, apex of mid tibia dark fuscous; tibial spurs dark fuscous with white tips; mid tarsomeres I–V dirty white with fuscous bases and apices, tip of mid tarsus grey; hind femur ochreous, hind tibia fuscous with median white ring; median spurs long, as long as about 2/3 of tibia length, grey with white tips, apical spurs short, grey, lighter grey at tip, hind tarsomere I fuscous with white sub-base, hind tarsomeres II–V dirty white with fuscous bases and apices, tip of hind tarsus dirty white. Abdomen ( Figs 495, 496): fuscous brown on terga II–V, and light brown with orange shading on tergum VI, anterior segments VI and VII of abdomen orange-white, lateral sides of abdomen creamy white (sternites) with five oblique dark brown stripes, sternum VII without an oblique stripe, creamy white with very strong orange shading.Abdominal opening rather small, shaped as an equilateral triangle, the horizontal joint, connecting the lateral sides of the abdominal opening convex, the corners of the triangular opening gently rounded, the anterior part of sternum I is with protruded and centrally puffed sclerotisation consisting of two narrowly triangular appendages with sclerotised costal margin that are mirroring each other to two symmetrical parts at 180°; the tergal joint without sclerotised margin, but stronger melanised and clearly distinguishable plate of tergum II separates tergal joint from the rest of the cuticle; sternal apodemes initiate at the gently rounded corners of abdominal opening are well developed, of mid-length, terminating at anterior 1/3 of sternum II, with thicker bases, slightly bent inwards; tergal apodemes initiate at sub-anterior part of tergum I at the lateral sides of abdominal opening, angled at sub-basal part, slightly bent outwards at mid part with curved apices dilating from each other; tergal apodemes rather long, terminating beyond sternal apodemes, at the mid of segment II. Posterior margin of segment VI in females lightly, broadly but visibly sclerotised.

Male genitalia: No data.

Female genitalia ( Figs 505, 506): Anterior segments of female abdomen strongly narrowing posteriorly. Papillae anales fused, sharply triangular, with curved basal joint, the basal surface and lateral sides are covered with rarely planted thin setae of different length, with the longest at the base of papillae anales; apophyses posteriores initiate at the lateral sides of papillae anales, rather long, of moderate thickness, with sharp apices reaching anterior margin of segment VIII; segment VIII trapezoid-shaped, short, narrowing towards posterior margin; apophyses anteriores with very broad, strongly sclerotised bases, with short slightly bent, distancing from each other apices that enter segment VII. Segment VII with a semi-oval, arc-shaped sterigmatic plate almost entirely occupying sternum VII. Ostium bursae opens as a narrowly cut gap almost at anterior margin of segment VII, with funnel-shaped, and strongly melanised lamella ante-vaginalis that transforms into a fold with a sickle-shaped sclerotisation on ductus bursae anteriorly; posteriorly lamella ante-vaginalis has two lateral digitiform, tuberculate appendages attached to the anterior margin of sternum VII; antrum very short, inside the upmost marginal part of segment VII; corpus bursae irregular sac-shaped with strongly enlarged initial posterior part, almost entirely covered with long more or less rectangular sclerotised plate with the marked central part which is with a row of tiny darts. Ductus seminalis enters ductus bursae, near the joint of ductus bursae with corpus bursae.

Individual variation: Sub-apical and apical ornamentation is variable till that extent that it might be different on right and left forewing within the same specimen: comma-shape white short stripe, apical spot sub-spot vary in size, shape and even presence/absence.

Bionomics: The host plant of this species is Mallotus polyadenos F. Muell. ( Euphorbiaceae ). Probably this species is monophagous, but it belongs to a complex of very closely related species feeding on Mallotus spp. plants. Most probably specific differentiation within this complex was related to the choice/preference of the host plant species. The mining period is from mid to late January. The flight period is in late January, early February.

Pupa ( Fig. 515): length including the body and antennae ca. 4.1 mm; pupal body length ca. 2.8 mm, length of metathoracic leg appendages 3.1 mm. Pupa shining light bronze, slightly darker at frons; labrum extremely well developed, cocoon cutter is rectangular, strongly sclerotised and covered with tuberculate fold, galea, antenna, meso- and metathoracic legs and fore wing appendages with strong bronze glow, labial palpus lanceolate between maxillae; appendages for future maxillary palpus, labial palpus, proboscis, legs, wings and antennae are well observable; the appendages for future antennae, posterior legs and wings are free, not attached to the pupal case, end of abdomen moves freely; appendages for future maxillary palpus, labial palpus, proboscis, fore and mid legs attached to each other but not fused in a pupal case; the appendages of labial palpus ca. 1/3 shorter than the appendages of maxillae, metathoracic appendages ca. 1 mm shorter than the appendages of antennae. Pupal body is rather slender with A5–A7 and A8–A10 sharply narrowing towards anterior part. Genital aperture on rounded prominent projection on anterior region of A9; anal orifice on A10 between two round tubercules; cremaster absent.

Mitogenomic data: The single mitogenomic sequence from the holotype is very distinct from the other congeners, but its placement within the genus (as sister to P. mallota sp. nov.) is poorly supported ( Fig. 638).

Distribution: Known only from the type locality: Australia: Queensland, Eubenangee Swamp National Park.

Etymology: The specific name derives from the name of type locality Eubenangee Swamp National Park in Queensland, Australia. It is a noun in apposition in the nominative case.