Diphtheroptila breynella 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 : 92-95

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

( Figs 138, 139, 155, 156, 183–187, 213, 214, 231, 233, 254, 263, 273, 279, 280, 638)

Type locality: Australia, Northern Territory, Berry Springs.

Type specimens: Holotype ♂: [labels verbatim] [1] Australia N.T. [Northern Territory]/ 12.42S 130.59E /Berry Springs em.[erged]/2 Feb [February] 1998/T. & M. Kumata. [2] Host 5792/ Breynia / cernua, DNA sample NULT025123, genitalia slide ANIC 6174, ANIC Acc. no 31 085528, in ANIC (Canberra).

Paratypes: 7 specimens (6♂, 1♀): Northern Territory : Paratype 1(♀): same locality data as for the holotype, 08 February 1998, T. & M. Kumata, Host 5798, DNA sample NULT024683, genitalia slide ANIC 6201 , ANIC Acc. no 31 085558, in ANIC (Canberra) .

Queensland: Paratype 2(♂): Queensland, 16.05S 145.29E, Cape Tribulation, Daintree NP, em.[erged] 22 March 1998, T. & M. Kumata. Host 6012, Breynia sp. ( Phyllanthaceae ). DNA sample NULT025248, genitalia slide ANIC 6175, ANIC Acc. no 31 085554. Paratype 3(♂): 17.26S 145.58 E, Eubenangee Swamp, Nat[National] Pk[Park], em.[erged] 23 January 1997, T. & M. Kumata, Host 5664 Breynia sp. , DNA sample NULT024674, genitalia slide ANIC 6193, ANIC Acc. no 31 085556. Paratype 4(♂): same data, DNA sample NULT024799, genitalia slide ANIC 6194, ANIC Acc. no 31 085557. Paratype 5(♂): same data, DNA sample NULT025503, genitalia slide ANIC 6192, ANIC Acc. no 31 085555. Paratype 6(♂): same data, except the date 26 January 1997. Paratype 7(♂): same data, in ANIC (Canberra).

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

Diagnosis: All species belonging to the genus Diphtheroptila externally are very similar. Moreover, following mitogenomic data the very short branches show close affinities among the congeneric species. To facilitate the diagnosis and identification we compare the new species D. breynella sp. nov. with the two most resembling species D. cornuta sp. nov. and D. virosae sp. nov. Despite the fact that general ornaments resemble the pattern in D. breynella sp. nov. and D. virosae sp. nov., however stripes and patches in D. breynella sp. nov. are snowy white strongly contrasting with beige-grey ground colour. Furthermore, the ornamental dorsal stripes, lines and patches are shorter and thicker than in new D. virosae sp. nov. The white colour of vertex and thorax can be a good diagnostic character separating the new species from D. virosae sp. nov. though both species belong to the same species group. Hindwing colour is also beige in D. breynella sp. nov. and not grey as it is in D. virosae sp. nov. In general, the D. breynella sp. nov. is lighter, more beige than grey, with strikingly contrasting white dorsal stripes and patches. Wing pattern and ornaments within this group are variable. In D. breynella sp. nov. tegumen is rectangular, apices of valvae broadly round, saccular sclerotisation narrow and short, transtilla bent rectangular tape-like, saccus short and broadly round. In D. virosae sp. nov., species that feeds on the same host plant Flueggea virosa (Roxb. ex Willd.) Royle , these micromorphological characters separate those two species. In D. virosae sp. nov. tegumen is clearly triangular, valvae with narrowing apices, saccular sclerotisation with a long narrow fold, transtilla with rounded lateral parts, saccus short but clearly triangular. Aedeagus is also diagnostic: in D. breynella sp. nov. the cornutus is biforked and a short digitiform appendix is present on vesica, in D. virosae sp. nov. aedeagus with a rod-like cornutus and appendix on vesica is absent. Female genitalia are diagnostic also especially in shape and number of signa: in D. breynella sp. nov. corpus bursae with one huge conus-shaped signum and in D. virosae sp. nov. two signa are present: one small comma-shaped and the other bigger more or less round with appendage. There are diagnostic differences in sclerotisations of ductus bursae and sterigma (see Figs 231, 233). Bionomics cannot serve for reliable diagnosis either, only it can assist partly. Both species D. breynella sp. nov. and D. virosae sp. nov. feed on the host plant belonging to the same plant species Flueggea virosa ( Phyllanthaceae ).

The external diagnostic characters of D. breynella sp. nov. separating it from the closely resembling species D. cornuta sp. nov. are as follows:

● Two oblique stripes at basis of dorsal margin are present in D. cornuta sp. nov., such stripes are absent in D. breynella sp. nov.

● The ornaments in D. breynella sp. nov. are bright white, thicker, clearly defined, while in D. cornuta sp. nov. they are dirty white with blurred edges.

● Vertex in D. breynella sp. nov. is shiningly white while in D. cornuta sp. nov. it is light ochreous with darker midden part.

The species-level diagnostic characters can be found only in the set of internal genital morphology and mitogenomics.

Description: Wingspan 5.5–6.0 mm; length of the forewing 2.8–3.0 mm ( Figs 138, 139).

Head ( Figs 155, 156): Vertex shiny snowy white with erect piliform scale projecting radially to all directions, occiput with two tufts of short white piliform scales, projecting posteriorly. Frons of the same colour as vertex, snowy white, covered with a bunch of suppressed scales, partly covering even eyes. Maxillary palpus white, slightly shorter than the first labial palpomere, with pointed apex. Labial palpus relatively long, drooping, with long white, some with greyish tips piliform scales of different length, hanging along the second palpomere, second palpomere widening in thickness with broader apical part, dirty white along outer lateral sides, terminal palpomere snowy white with sharply pointed apex, labial palpus ca. 2, 5× longer than the eye. Antenna bright beige with light fuscous, consisting of fuscous piliform narrow scales forming longitudinal thin lines and lighter apices, ventrally uniformly light shining ochreous, pedicel short, approximately twice shorter than the second flagellomere, slightly darker in colour; scape dorsally white with brownish apex, ventrally almost white with 5–6 short, thick, white pecten.

Thorax ( Figs 138, 139, 183–187): white with ochreous anterior part, tegula ochreous at base, apical half white. Forewing narrowly elongated, equal in width along all its length, with a gently rounded apex, ground colour is bicoloured, grey-fuscous at costal part, and ochreous at dorsal part, wing ornamentation is also divided into costal and dorsal; on costa: basal part without any ornamentation, bright white spot at 1/2 of forewing followed by a row of seven spots of different shading of white and of different size; dorsal margin heavily decorated with shining white, short, reaching half of the forewing, broad, not edged stripes grouped by three as following: a basal spot on the basis of the dorsum, two groups consisting of three stripes follow the dorsal margin until the mid of forewing, a group of shorter irregular stripes not reaching the midline of the forewing, a group of tornal spots consisting of two bigger and two smaller spots, apical spot indistinct but present. The fringe line is dark fuscous and present only in tornal area; fringe long, at the distal part of dorsum, light grey, with light silver shine, and shorter at median part of the dorsum of the forewing, shading a little bit more ochreous towards the tornus of forewing. 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 beige at the basis and light beige at apical part, fore tibia dirty white at the median part and ochreous fuscous in the apical part, tarsomeres light grey with darker apices; mid-femur light ochreous with light fuscous basal half, mid tibia ochreous with fuscous median part, mid tibia with a row of short stout brown spines stretching along the length of tibia, tibial spurs about as long as the first tarsomere, of the same colour as tibia and tarsus, tarsus dark fuscous with dirty white apices, not ringed, tip of tarsus ochreous; hind femur fuscous, hind tibia fuscous ochreous with short, stout, sharp, spines in a row at the inner side of tibia decreasing in size and even continuing on the first tarsomere, medial spurs dirty white, almost as long as hind tibia, apical spurs shorter than medial spurs, ca. 1/3 of the length of tarsomere I, tarsomeres light fuscous with dirty white apices, tip is dirty white.

Abdomen ( Figs 183–186, 254, 263): grey, terminal tergites and last genital segments of lighter colouration, sternites light ochreous; four broad, dark ochreous oblique stripes present on lateral sides of the abdomen. Margins of abdominal opening on sternum II strongly sclerotised, lateral sides sharply distancing towards posterior ends, ventral crossing joint very narrow, strongly sclerotised with hardly visible liftings at lateral sides; sternal apodemes initiating at the corners of abdominal opening are well developed, narrow, thin, bent; a lightly melanised joint connecting lateral sides of abdominal opening on tergum I is present, that is an initiating point of tergal apodemes; tergal apodemes sharply hooked at bases, thin, straight, rather long, reaching midden part of tergum II; apical part of tergal apodemes round. Anterior segment VI in females without sclerotisations; anterior segment VII in males with two narrow, sclerotised semi-rings which are the androconial characters. Anterior margins of segments III–VI in females and III–VII as well as posterior margin of segment VII in males narrowly and finely melanised.

Male genitalia ( Figs 213, 214): Teguminal arms form more or less rectangular figure, uncus flexible, sclerotised only in the central part, tegumen with strongly sclerotised margins and central joint that is clearly visible; valvae slightly wider at central part and slightly narrower at cucullus, apices broadly and gently rounded; very strongly setose at mid and sub-apical margins with long, stout setae, basal part of sacculus carries a small but very obvious prolonged, dentate sclerotisation, transtilla incomplete, juxta as prolonged rectangular tape, vinculum well developed, consisting of two fused parts with a clearly visible and strongly sclerotised suture that ends with an arrow-shaped small projection; saccus small but present as a broadly sickle-shaped projection. Aedeagus short, thick, vesica triangular, with a gently rounded apex, carries a biforked cornutus and a digitiform projection; the distinction between vesica and coecum is very clear: vesica large, broad, triangular, coecum small with gently rounded anterior part.

Female genitalia: Papillae anales flattened and fused, setose with stout thin setae of different lengths; apophyses posteriores short, rather thick with blunt apices; segment VIII carries a very broad sclerotised basal semi-ringed sclerotisation of apophyses anteriores, anterior part of apophyses anteriores short, shorter than of apophyses posteriores, slender, sharpening anteriorly, terminating at posterior margin of segment VII; segment VII strongly melanised, sternum VII with tiny tubercle sclerotisations; ostium bursae opens at anterior part of sternum VII as a cup-like melanised opening, antrum and ductus bursae rather broad, colliculum strongly sclerotised entirely, with peculiar spiracle sclerotisation at mid of ductus bursae; transition between ductus bursae and corpus bursae without distinction, with strongly melanised, thin and long folds, anterior part of the wall of corpus bursae with visible scales, corpus bursae carries one very big conus-shaped and strongly sclerotised signum; ductus seminalis joins ductus bursae anteriorly sterigmatic spiracle sclerotisation.

Individual variation: The Type specimens shows a slight variation in colour shading of ochreous and fuscous. Also, the colouration and patches on legs slightly differ in paratype specimens from ochreous grey to darker fuscous colouration. The ornamental pattern of the forewing is also variable from shorter thicker white stripes in the holotype to longer thinner stripes in the paratypes. However, the general ornamental design is the same in all specimens belonging to the Type specimens. In this treatment, we take a broader species concept accepting the fact that a broad intraspecific variation might exist in tropical Gracillariidae species and within Ornixolinae subfamily in particular (see implicit indication in De Prins et al. 2023). The variation is observed even in the internal morphology: valvae in type specimens can be of slightly different length and thickness, especially variable is the thickness of the vinculum. However, the general characteristics as described above are attributed to all type specimens that are presented in this study.

Bionomics ( Figs 273, 279, 280): The larva is not a monophagous leaf miner feeder, type specimens are reared from the genus Breynia ( Phyllanthaceae ) plant hosts; the holotype was reared from Breynia cernua (Poir.) Müll. Arg. and the paratypes from an unidentified other Breynia species as well as from Flueggea virosa (Roxb. ex Willd.) Royle ( Phyllanthaceae ) ( Figs 279, 280). The mining period of this species can be long depending upon the geographical location and microclimate. The difference of emergence specimens is 46 days. Such a long mining period is rarely known from biological data records of tropical and even Palaearctic Gracillariidae species.

Mitogenomic data: Although sampled extensively across its geographic distribution, the mitochondrial genomes of the Northern Territory and Queensland populations differ very little (about 1% uncorrected pairwise distance), yet the differences to the closest relatives are substantial (about 8% uncorrected pairwise distance), resulting in the monophyly of the species being maximally supported by all analyses. Relationships between most Diphtheroptila species are only poorly supported, including the sister relationship between D. breynella sp. nov. and the clade comprising D. glochidia sp. nov., D. oxyloga , D. virosae sp. nov., D. nix sp. nov. and D. crotonella sp. nov. ( Fig. 638).

Distribution: Known from two administrative regions in Australia: Northern Territory and Queensland.

Etymology: The specific name is derived from the genus name of the host plant Breynia cernua (Poir.) Müll. It is an adjective in feminine gender with the diminutive suffix - ella.