Polydema macaranga De Prins, Sruoga & Zwick, 2025

Prins, Jurate De, Hartley, Diana, Sruoga, Virginijus, Nicholls, James, Wallace, Jesse & Zwick, Andreas, 2025, Diversity of Australian Ornixolinae (Lepidoptera: Gracillariidae) with taxonomic and nomenclatural acts within the related taxa (Acrocercopinae and Gracillariinae) based on the evidence of museomics, bionomics, and mitogenomics, Zootaxa 5616 (1), pp. 1-340 : 236-240

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

( Figs 482, 483, 488, 489, 497, 498, 504, 507, 510, 513, 516, 517)

Type locality: Australia, Queensland, Kuranda.

Type specimens: Holotype ♀: [labels verbatim] [1] Australia Q. [Queensland]/ Kuranda /nr. Cairns /em.[erged] 8 IV[April]1991/ T. Kumata leg. [2] genitalia on slide/ No Grc-5692/ T. Kumata 1991. [3] ANIC /genitalia slide/No 21378. [4] Host 4198/ Macaranga/involucrata. [5] Polydema / Det. T. Kumata 199[7], DNA sample NULT025044, ANIC Acc. no 31 085539, in ANIC (Canberra).

Paratype ♂: Australia, Queensland, Kuranda, Cairns , emerged 06 April 1991, leg. T. Kumata, Host 4198, Macaranga involucrata Baill. ( Euphorbiaceae ), Genitalia on slide No Grc-5691, T. Kumata, 1991, ANIC Image, DNA sample NULT025169, ANIC Acc. no 31 081108, in ANIC (Canberra).

Additional specimens excluded from the type specimens: Specimen 1: without abdomen, Australia, Queensland, 16.49°S 145.38°E, Kuranda, emerged 3 February 1997, T. & M. Kumata, Host 5702 Macaranga sp., ANIC image, DNA sample, ANIC Acc. no 31 075736. Specimen 2: without abdomen, same data, ANIC Acc. no 31 075737, in ANIC (Canberra) .

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

Diagnosis: Polydema macaranga sp. nov. clearly belongs to the same genus Polydema and the same species group as P. mallota sp. nov., but they are easily separated by external wing pattern and bionomics. The ornaments in P. macaranga sp. nov. are brighter, the lines of ornaments reversed Y and reversed V are broader and more diffused. In P. macaranga sp. nov. apical spot is as a long broad clear black stripe, in P. mallota sp. nov. the apical spot is bicoloured white/black, round, mid-sized. The biggest morphological differences are in female genitalia: the huge signum is highly diagnostic. In P. mallota sp. nov. the signum is as a broad ornamental tape wrapping the ductus bursae, while in P. macaranga sp. nov. the signum is as a broad flat plate with sclerotised central suture running along the entire length of the signal plate. The connection between ductus bursae and corpus bursae in P. macaranga sp. nov. is without the special morphological structure as an oval strongly sclerotised plug, such sclerotisation is present in P. mallota sp. nov. There are also tiny morphological differences in the shape of sterigmatic plate and the form of the lamella ante-vaginalis ( Fig. 507).

Huge signal area, fully sclerotised ductus bursae, position of ostium bursae on sub-anterior margin of sternum VII, semi-oval shape of sterigmatic plate on sternum VII, similar length and shape of apophyses, fused, triangular-shaped at anterior part papillae anales—morphological characters that demonstrate the affinity of both species P. mallota sp. nov. and P. macaranga sp. nov. which are sympatric and synchronic (with one week difference only), and mining the plants belonging to the same plant family Euphorbiaceae . However, both species feed on different genera of plants: larvae of P. mallota sp. nov. feed on Mallotus paniculatus , while larvae of P. macaranga sp. nov. feed on Macaranga spp.

Description: Wingspan ca. 5.0–6.0 mm; length of the forewing 2.4–3.0 mm ( Figs. 482, 483).

Head ( Figs. 488, 489): vertex smooth, golden ochreous, with dirty-white lateral parts bordering the eyes, two tufts of short piliform scales radially directed cover the occiput. Frons light ochreous golden, labrum snowy white. Maxillary palpus short, ca. as long as scape, erect, dirty white with golden apex. Labial palpus relatively long, ca. 2.5× longer than the diameter of the eye, slightly upcurved, basal palpomere, short, dirty white with fuscous patch at inner side of palpomere, palpomere II carries a long tuft of piliform scales, longer than palpomere II, the tufts consist of intermixture of white, ochreous and dark brown piliform scales, apical palpomere covered with roughly attached scales, white at base and ochreous with two irregular dark brown lines at sub-base and at sub-apex.Antenna light ochreous, flagellomeres with dark dorsal surface and light apices, ventrally antenna uniformly light ochreous, pedicel white, approximately as long as the following flagellomere, scape shining white, with long white pecten of different lengths.

Thorax ( Figs 482, 483, 497, 498): thorax and tegula light ochreous. Forewing narrowly elongated, equal in width along all its length, with a gently rounded apex, ground colour ochreous with dark fuscous patches at sub-apical and apical part of forewing; two dirty white curved stripes and patches are at base of forewing, dirty white irregular fascia, edged from both sides at 1/3 of forewing, two white spots, edged with dark scales present on costa, a reversed Y ornament is at mid of forewing, followed by narrow oblique stripe directed towards apex, apical part of costa carries white or fuscous irregular patches, apical stripe rather long, oblique towards apex; apical line rather thick, black, gently following apical part of the forewing and abruptly ends at tornus; the fringe line black, gently following the apical margin. Fringe light grey at tornus with darker shading toward basal part. Hindwing narrow, elongate, sharply pointed, ground colour ochreous-fuscous, 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 ochreous, fore tibia dark fuscous with two white patches at base and at midden, fore tarsomeres with white bases and dark fuscous apices, tip of tarsus dark ochreous; mid femur ochreous fuscous, tibia white with fuscous sub-base and fuscous apex, tarsomere I white at base, fuscous at median part, and white at apex, tarsomeres II–III fuscous at bases and dirty white at apices, tarsomeres IV–V white at bases and fuscous at apices, tip of tarsus light grey; hind femur ochreous, hind tibia dirty white with fuscous apical 1/3, median spurs long, ca. as long as about 2/3 of tibia length, grey, apical spurs short, grey, darker at apices.

Abdomen ( Figs 510, 513): Abdominal opening rather small, shaped as an triangle, the horizontal joint, connecting the lateral sides of the abdominal opening convex, the anterior part of sternum I is with protruded and centrally puffed sclerotisation; the tergal joint is marked as a strongly melanised cuticle; sternal apodemes initiating at the corners of abdominal opening are well developed, of mid-length, terminating at anterior 1/3 of sternum II, as appendages, slightly bent inwards, with rather sharp apices; tergal apodemes initiate at sub-anterior part of tergum I, at the lateral sides of abdominal opening, with a short, sharply pointed appendage at sub-base; tergal apodemes rather long, terminating at the mid of segment II, straight. Posterior margin of segment VI in females lightly, broadly and visibly sclerotised. Two brightly red, big, oval androconial sclerotisations are present on the ventral side of the abdomen in males; the first brightly red marking is situated in the cuticle joint between sterna II–III and the second marking is situated in the cuticle joint between sterna III–IV.

Male genitalia ( Fig. 504): Tegumen moderately sclerotised as equilateral triangle; uncus as two narrow, strongly sclerotised lateral arms approaching each other well beyond the teguminal top; anal tube slightly protruding as short, blunt, cylindrical tube. Valvae directed down towards vinculum with narrow blunt apices; costal margin of valvae slightly bent, but strongly narrowly sclerotised, ventral margin of valvae wrinkled, flexible, with bigger or smaller waves; the inner surface of valvae covered with short, pressed setae of different lengths; transtilla incomplete but juxta is circular shaped and its posterior part coming well between costal bases of valvae. Vinculum is very broad Ushaped, complex, as a fused structure of three mirroring each other plates; a horizontal rectangle, semi-round lateral plate, and the anterior part of U-formation crossed by mid suture nicely dividing vinculum into the symmetrical left and right sides; saccus well developed, narrow, digitiform appendix. Data on aedeagus not available.

Female genitalia ( Fig. 507): Papillae anales fused, but gently triangular, covered with rarely planted thin setae of different length; apophyses posteriores with broad bases, sharply narrowing towards thin and short anterior part; apophyses posteriores terminate in the sub-posterior sector of segment VIII; apophyses anteriores initiate at the anterior margin of segment VIII; the basal part of apophyses anteriores is sclerotised and fully fused into a ring, the anterior part of the apophyses anteriores is strongly divided into two parts: i) broad, rather thick posterior part in the form of two lateral appendages situated in segment VIII and ii) sharp needle like, strongly sclerotised anterior part of the appendages that terminate in the mid of segment VII. Segment VII moderately sclerotised with semi-oval sterigma, occupying almost entirely sternum VII. Ostium bursae opens at sub-anterior part of sternum VII, lamella post-vaginalis rather simple, just stronger sclerotisation round the opening of ostium bursae, while lamella ante-vaginalis with two narrow, strongly sclerotised appendages. Antrum+ductus bursae entirely sclerotised, making the distinction between ductus and corpus bursae very clear. Corpus bursae is prolonged sac-shaped with strikingly diagnostic colliculum. Colliculum is shaped as prolonged very strongly sclerotised plate, covering almost entirely corpus bursae, except the anterior part; a prolonged mid suture runs along the entire length of colliculum that has a function of a signal plate. Ductus seminalis enters ductus bursae anteriad the sclerotised antrum which has the shape of the cork.

Individual variation: There is a slight variation in the pattern of ornamentation, especially on the costal margin, it might vary in shape and number of small dirty white spots. The shape, length and size of apical spot/stripe varies from a short thick, almost round spot till a long, fine, but well-defined stripe.

Bionomics: The specimens belonging to the Type specimens were reared from Macaranga involucrata Baill. ( Euphorbiaceae ). The species is probably not monophagous but feeds on closely related host plants belonging to the same genus. The mining period of this species is in early April but might be earlier. The additional specimens were collected in different year, but in the same locality, so the phenology might be different in different years depending upon microclimatic conditions. Based on collection material we presume that the mining period of this species might be longer than mean for the other complexes of Ornixolinae species. The flight period is in early April.

Pupa ( Figs 516, 517): length including the body and antennae ca. 4.1 mm; pupal body length ca. 3.7 mm. The head possesses a cocoon cutter with an extending short cylindrical process which is dentate at the anteriorly; maxillae with enlarged and puffed basal part that is darker, anterior part is covered with tiny tubercules; appendages for future antennae ca. 0.7 mm longer than the abdomen; the appendages for future antennae, posterior legs and wings are free, not attached to the pupal case, end of abdomen is not fixed and can move; appendages for future maxillary palpus, labial palpus, proboscis, fore and mid legs attached to each other but not fused in a pupal case; appendages for maxillary palpus and labial palpus are relatively long, ca. 2/3 of pupal body length; abdominal segments VII–IX ventrally smooth; the abdominal segment IX is relatively small, the abdominal anterior part is broadly round.

Mitogenomic data: No data (all specimens without abdomens).

Distribution: Known only from the type locality: Australia: Queensland, Kuranda.

Etymology: The species name derives from the genus name of the host plant Macaranga involucrata Baill. It is a noun in apposition, gender feminine.