Diphtheroptila cornuta De Prins, Sruoga & Zwick, 2025

Diphtheroptila cornuta De Prins, Sruoga & Zwick , sp. nov.

( Figs 142, 143, 159, 160, 190, 191, 217, 218, 237, 256, 265, 274, 282–284, 638)

Type locality: Australia, Northern Territory, Darwin.

Type specimens: Holotype ♀: [labels verbatim] [1] Australia N.T. [Northern Territory]/ 12.21S 130.52E /Darwin/ Casuarina C. R. em.[erged]/ 5 Feb 1998 /T. & M. Kumata. [2] Host 5812/ Glochidion / sp., DNA sample NULT025266, genitalia slide ANIC 6190, ANIC Acc. no 31 085527, in ANIC (Canberra).

Paratypes: 5 specimens: Paratype 1(♀) same locality data except the date 10 February 1998, T. & M. Kumata. Host 5812, Glochidion sp. ( Phyllanthaceae ), DNA sample NULT025381, genitalia slide ANIC 6191, ANIC Acc. no 31 085567. Paratype 2: without abdomen, same data, except the date 8 February, 1998. Host 5756 Glochidion sp. Paratype 3(♀): Northern Territory, 12.42S 130.59E, Berry Springs, em.[erged] 09 February 1998, T. & M. Kumata. Host 5791 Glochidion sp. , DNA sample NULT025141, genitalia slide ANIC 6189, ANIC Acc. no 31 085569. Paratype 4(♂) same locality data except the date 07 February 1998, Host 5791 Glochidion sp. , DNA sample NULT025026, genitalia slide ANIC 6188, ANIC Acc. no 31 085570, in ANIC (Canberra).

Queensland: Paratype 5(♂): Kuranda, 16.49S 145.38E, em.[erged] 05 February 1997, T. & M. Kumata, Host 5708 Glochidion sp. , DNA sample NULT024665, genitalia slide ANIC 6185 About ANIC , ANIC Acc. no 31 085565, in ANIC (Canberra) GoogleMaps .

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

Diagnosis: This species belongs to the same natural species group within the genus Diphtheroptila , feeding on Phyllanthaceae . It mostly reminds of D. breynella sp. nov., feeding on Breynia sp. , due to contrasting forewing ornamentation. However, following the mitogenomic characteristics and internal morphology, it is the sister species of D. ochridorsellum ( Meyrick, 1880) . Though the general wing pattern of D. cornuta sp. nov. and D. breynella sp. nov. resembles each other, the diagnostic differences are detectable easily: transverse fasciae in D. cornuta sp. nov. are not interrupted, stripes and fascia are grouped together. In D. breynella sp. nov. the predominant forewing pattern is as follows: short, not reaching midline, parallelly oblique dorsal strigulae, arranged in a row on dorsum; fasciae in D. breynella sp. nov. are absent, or consisting of interrupted costal and dorsal strigulae which meet at the midline of the forewing. Vertex can serve for diagnosis as well: in D. cornuta sp. nov. it is smooth, with an intermixture of ochreous scales on occiput, while in D. breynella sp. nov. it is white, rough, piliform scales radially projecting. The most reliable diagnostic characters between both species are in two independent data sets: molecular and bionomics— D. cornuta sp. nov. feeds on Glochidion sp. while D. breynella sp. nov. feeds on Breynia sp. However, bionomics will not diagnose D. cornuta sp. nov. from other Diphtheroptila new species feeding on Glochidion spp. such as D. glochidia sp. nov., D. virosae sp. nov., and D. glochidiella sp. nov. Despite the fact that the wing pattern is variable, nevertheless it can serve to separate D. cornuta sp. nov. from related species feeding on the closely related plants belonging to the same genus Glochidion , due to its contrasting white fasciae and ornamental stripes. The unique specific diagnostic characters should be searched in the internal genital morphology, bionomics and mitogenomics.

It is interesting to mention that D. cornuta sp. nov. from external characters resembles other Glochidion feeding Diphtheroptila species; however, from internal morphology it mostly resembles D. ochridorsellum . In male genitalia, both species possess a reduced tegumen, curved with straight and flat apices valvae, extremely well-developed sacculus and horn-shaped clavus. The diagnostic differences in internal male morphology between these two species are as follows:

● In D. ochridorsellum the clavus is a short thick bent appendage with blunt apex. In D. cornuta sp. nov. the clavus is long, bent, double, narrow horn-like appendages with sharp apices that reach the cucullus area.

● In D. ochridorsellum peniculus is ampulla-shaped with rounded anterior part; in D. cornuta sp. nov. it is arrow-shaped with sharp anterior part.

● In D. ochridorsellum vinculum is narrow, semi-round, saccus very narrow sickle-shaped, while in D.

cornuta sp. nov. vinculum is rather broad, saccus is more or less triangular-shaped with a rounded anterior part.

Females are more diagnostic than males separating these two sister species in the mitogenomic cladogram:

● In D. ochridorsellum lamella ante-vaginalis is U-shaped with broad posterior parts, while in D. cornuta sp.

nov. lamella ante-vaginalis is bell-shaped, clearly rounded with broader anterior part.

● Sterigma is also diagnostic: in D. ochridorsellum sterigma is only in central part of sternum VII and it is bow-shaped, while in D. cornuta sp. nov. sterigma occupies almost entirely sternum VII with strongly sclerotised posterior margin which is W-shaped.

● Antrum/colliculum in D. ochridorsellum is covered by a fully sclerotised prolonged plate, while antrum/ colliculum in D. cornuta sp. nov. only margins at the anterior part of the antral plate are strongly sclerotised.

Description: Wingspan ca. 6.0–7.0 mm; length of the forewing ca. 2.8–3.0 mm ( Figs 142, 143).

Head ( Figs 159, 160): Vertex light ochreous smooth, with intermixture of ochreous fuscous piliform scales, initiating at occiput and radiating on vertex toward antenna; occiput with two tufts of piliform scales projecting to two directions: laterad and posteriorly. Frons white with some ochreous shading between the central part of the eyes. Maxillary palpus small, as long as about 2/3 the eye diameter, projecting anteriorly, bicoloured, basic palpomere dark brown and apical palpomere white, no hanging bunches or tufts of scales are visible. Labial palpus relatively long, as long as ca. 2× of eye diameter, palpus gently distancing from each other, lightly lifted at apices, palpomere I and palpomere II equipped with long, hanging, dark ochreous scales from outwards and white drooping piliform scales from inner side, apical palpomere glabrous with sharp apex. Antenna ochreous with dirty white intermixed with dark ochreous prolonged scales forming tiny longitudinal lines, apices of flagellomeres light, flagellum not ringed, ventrally antenna light ochreous basally and darker ochreous, the same colour and shading as dorsal side, pedicel as long as the second flagellomere, dirty white dorsally with dark ochreous scales from anterior and posterior sides, slightly thicker at basis; scape dorsally and laterally white with intermixture of some ochreous scales at apical with 10–12 light ochreous pecten of different length.

Thorax ( Figs 142, 143, 190, 191): dirty white with intermixture of light ochreous, tegula ochreous with apical part. Forewing narrowly elongated, equal in width along all its length, with a gently rounded apex, ground colour ochreous fuscous with lighter dorsal part, wing ornamentation might be variable not only among the specimens but also between right and left forewing. Forewing with two indistinct oblique light ochreous stripes at base of dorsum, complete or interrupted fascia with irregular edging at 1/3 of forewing, broader, oblique, transverse and irregular fascia just beyond of mid of forewing, two strigulae, dorsal and costal separated by an area of fuscous scales at distal 1/3 of forewing, bright white, semi-round apical spot on costal margin at apex, apical fuscous spot fused with fuscous sub-apical patch forming dark irregular, prolonged dark patch, four broader ochreous spots separated by irregular, thin ochreous lines and stripes on light dorsal margin; apex of forewing is edged by very thin fuscous line. The fringe line is dark fuscous, gently surrounding apex, termen and tornus; fringe long, at the sub-distal part of dorsum, light grey, with light silver shine, and shorter at median part of the dorsum of the forewing, unicoloured. Hindwing narrow, elongate, sharply pointed, ground colour light ochreous-fuscous, fringe short at costa and 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. The fore femur is dark ochreous, fore tibia dark ochreous dorsally and dirty white ventrally, tarsomere I fuscous ochreous with light median part, tarsomere II dirty white at basal part and fuscous at apical part, tarsomeres III–V fuscous at base and dirty white at apical part, tip of tarsus dark grey; mid-femur and tibia fuscous with prolonged light ochreous patches, apical spurs short, about 1/2 length of tarsomere I, light fuscous, tarsomere I grey with lighter basal and apical areas, terminal tarsomeres grey; hind femur three-coloured: white at basal and median areas, dark brown at sub-basal area, ochreous fuscous at apical area, hind tibia fuscous ochreous with short, stout, sharp, spines in a row at inner side of tibia decreasing in size and even continuing on the first tarsomere, medial spurs fuscous, almost as long as hind tibia, apical spurs short, ca. 1/3 of the length of tarsomere I, light grey, tarsomeres light fuscous with brushes of porrect short piliform scales at apices, tip is dirty white.

Abdomen ( Figs 190, 191, 256, 265): tergites dark ochreous, median part of sternites ochreous-white, lateral sides of abdomen (tergites and sternites) are dirty white with four oblique bronze-ochreous stripes. Abdominal opening as equilateral triangle, margins of abdominal opening on sternum II strongly sclerotised, ventral crossing joint with very narrow sclerotised anterior margin; sternal apodemes initiating at the corners of abdominal opening are well developed, slightly bent, thin, entering anterior 1/3 of segment II; a lightly melanised sickle-shaped joint connects lateral sides of abdominal opening on tergum I, which is an initiating point of tergal apodemes; tergal apodemes sharply hooked at bases, slender, straight, rather long, reaching sub-posterior 1/3 part of tergum II; apical part of tergal apodemes is blunt.Anterior segment VI in females without sclerotisations; anterior segment VII in males with two narrow, sclerotised semi-rings. Anterior margins of segments III–VI in females and III–VII in males narrowly and finely sclerotised, intersegmental joins are broad and weakly melanised.

Male genitalia ( Figs 217, 218): Tegumen short, but extremely strongly developed and sclerotised; teguminal arms are as very broad plates with curved inner margin; anal tube strongly protruding, extending as long as ca. 1/2 of valvae with narrow pyramidal apex; costal margin of valvae gently sinuating, cucullus gently round, corona with straightly cut margin making apices of valvae prolonged narrow plates when they are in closed position; ventral margin of valvae more or less straight, sub-apical and apical area very densely covered with long, stout, sharp, spiculose setae; basal part of valvae slightly folded; a strongly sclerotised claval appendage initiates at sub-basal part of ventral surface of valvae, the clavus is shaped as a pair (double), strongly sclerotised, bent, horn-shaped with sharp apices appendages; sacculus area extremely well-developed as broad folded plate with narrowing anterior part that reaches the setose margin of valvae; transtilla incomplete; basal parts of saccular appendages form juxta; peniculi as semi-oval plates with a pair of stout setae; vinculum is well-developed, U-shaped, anterior part broader, the anterior suture of vincular joint is very well observable, crossing the central part of vinculum; saccus short but well developed, more or less triangular with equal lateral margins, crossed by mid-suture with protruding digitiform appendage at the anterior part. Aedeagus is slightly longer that 1/2 of valva, broad, thick, well developed with extremely peculiar cornutus, consisting of one lateral digitiform appendage and a crest with a lot of branched and forked protuberances.

Female genitalia ( Fig. 237): Papillae anales fused and flattened, covered with long, thin, setae of different lengths; apophyses posteriores short, broad, flattened with sharply hooked apices, terminating at posterior margin of segment VIII, segment VIII is short, weakly sclerotised; apophyses anteriores initiate at segment VII at the posterior edge of sterigma on sternum VII, very short digitiform appendages, ca. 2× shorter than posterior apophyses; segment VII moderately sclerotised, with folded broad sterigma occupying almost entirely sternum VII; the posterior margin of sterigma W-shaped, with broad intermediate joint, and with very strongly sclerotised broad posterior margin; ostium bursae opens at sub-anterior margin of sternum VII, enringed by fused circular lamella with very strongly sclerotised broad internal surface; antrum surrounded by a sclerotised collicular plate with open ended anterior part. Ductus bursae very short, gently transforming into long sac-shaped corpus bursae, with one triangular-shaped signum at sub-anterior anterior part; signum bears one short pointed projection; wall of corpus bursae with squamous melanised covering. Bulla seminalis significantly shorter and smaller than corpus bursae, ductus seminalis lightly sclerotised with longitudinal lines, enters ductus bursae at the joint of ductus and corpus bursae.

Individual variation: Wing pattern is exceptionally variable among the specimens of the Type specimens, with irregular stripes, lines and patches. Despite the observed variation, it falls within the general description presented above.

Bionomics ( Figs 274, 282–284): The larvae were reared from four unidentified species of host plants belonging to the same plant genus Glochidion ( Phyllanthaceae ). The mining period is in early February. The flight period and adult activity start in the second decade of February.

Mitogenomic data: The species is closely related to and maximally supported as sister of D. ochridorsellum ( Fig. 638).

Distribution: Known from three localities: two localities in the same administrative region of Australia: Northern Territory, and one locality in Queensland.

Etymology: The specific name cornuta derives from the Latin word cornus, meaning horn. The name points to the horn-shaped clavus in male genitalia. It is an adjective in feminine gender.