Diphtheroptila ochridorsellum ( Meyrick, 1880 )

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 : 116-121

Diphtheroptila ochridorsellum ( Meyrick, 1880)

( Figs 151, 174–176, 180, 248, 249 260, 270, 638)

“ Cor .[iscium] ochridorsellum , n. sp. ”—Meyrick, E., 1880. Proceedings of the Linnean Society of New South Wales 5(1): 132– 182, 204–271. https://www.biodiversitylibrary.org/page/6455831

Coriscium ochridorsella — Meyrick 1907: 149.

Acrocercops ochridorsella — Turner 1940: 61.

Diphtheroptila ochridorsellum — Nielsen & Kumata 1996: 48; De Prins & De Prins 2005: 175.

Type locality: [ Australia, New South Wales], Sydney.

Type specimens: 12 Syntypes (♂ and ♀), in NHMUK (London) .

Specimens examined: 4 syntypes: Syntype 1: [1]‘Sydney/N[new] S[outh] Wales / 30 January 1880 ’; [2] ‘Meyrick Coll./B. M. 1938-290’; [3] ‘Syntype’; [4] ‘ Acrocercops / ochridorsella /12/7 Meyr./E. Meyrick det./in Meyrick Coll.’; [5] ‘BMNH(E) 1406455. Syntype 2: [1]‘Sydney/N[new] S[outh] Wales / 15 December 1877 ’; [2] ‘Meyrick Coll./ B. M. 1938-290’; [3] ‘Syntype’; [4] ‘ Acrocercops / ochridorsella /12/1 Meyr./E. Meyrick det./in Meyrick Coll.’; [5] ‘ ochridorsella Meyr’; [6] ‘BMNH(E) 1406200. Syntype 3: [1]‘Sydney/N[new] S[outh] Wales / 15 December 1877 ’; [2] ‘Meyrick Coll./B. M. 1938-290’; [3] ‘Syntype’; [4] ‘ Acrocercops / ochridorsella /12/3 Meyr./E. Meyrick det./in Meyrick Coll.’; [5] ‘BMNH(E) 1406327. Syntype 4: [1]‘Sydney/N[new] S[outh] Wales / 9 December 1877 ’; [2] ‘Meyrick Coll./B. M. 1938-290’; [3] ‘Syntype’; [4] ‘ Acrocercops / ochridorsella /12/4 Meyr./E. Meyrick det./in Meyrick Coll.’; [5] ‘BMNH(E) 1406235, in NHMUK (London, June 2024).

Lectotype designation: Hereby, we designate as the lectotype of the species Coriscium ochridorsellum Meyrick, 1880 the female specimen with the abdomen, right antenna broken, belonging to the syntype series and carrying the following labels: [1] ‘Sydney/N. S. [New South] Wales‘/ 15 December 1877 (handwritten on dark beige paper), [2]’Meyrick Coll./B. M. 1938-290’ (printed on white paper), [3] ‘Syntype‘ (round label outlined blue solid line), [4] ‘ ochridorsella Meyr‘ (handwritten with black Indian ink on beige paper’, [5] Acrocercops / ochridorsella /12/1 Meyr./E. Meyrick det./in Meyrick Coll.’ (three upper lines handwritten with black Indian ink, two lower lines printed on white paper), [6] ‘BMNH(E) 1406200’, in NHMUK (London).

Paralectotypes: 3 specimens: Paralectotype 1(♂), with abdomen: belonging to the syntype series and carrying the following labels: [1] ‘Sydney/N. S. [New South] Wales‘/ 30 January 1880 (handwritten on dark beige paper), [2]’Meyrick Coll./B. M. 1938-290’ (printed on white paper), [3] ‘Syntype‘ (round label outlined blue solid line), [4] ‘ Acrocercops / ochridorsella /12/7 Meyr./E. Meyrick det./in Meyrick Coll.’ (three upper lines handwritten with black Indian ink, two lower lines printed on white paper), [5] ‘BMNH(E) 1406455’, Paralectotype 2: [1]‘Sydney/ N[new] S[outh] Wales / 15 December 1877 ’; [2] ‘Meyrick Coll./B. M. 1938-290’; [3] ‘Syntype’; [4] ‘ Acrocercops / ochridorsella /12/3 Meyr./E. Meyrick det./in Meyrick Coll.’; [5] ‘BMNH(E) 1406327. Paralectotype 3: [1]‘Sydney/ N[new] S[outh] Wales / 9 December 1877 ’; [2] ‘Meyrick Coll./B. M. 1938-290’; [3] ‘Syntype’; [4] ‘ Acrocercops / ochridorsella /12/4 Meyr./E. Meyrick det./in Meyrick Coll.’; [5] ‘BMNH(E) 1406235, in NHMUK (London, June 2024).

The lectotype is designated as part of our taxonomic work to enhance the stability of nomenclature (Declaration 44— Amendment of Article 74.7.3) with a purpose to delineate this species-group taxon Coriscium ochridorsellum Meyrick, 1880 . This designation will preserve stability in nomenclature ( ICZN Recommendation 74A). We gave the preference to the female specimen indicated as ‘12/1 Meyr.’ with a handwritten label ‘ ochridorsella ’ by E. Meyrick, present in the Insect Collection of the Natural History Museum ( London ) (data from June 2024), and curated by the former curator Dr. Jurate De Prins who provided it with the unique QR Code BMNH(E) 1406200 ( ICZN Recommendations 74B, C, D). The locality of the lectotype specimen is verified and included in the Global Taxonomic Database of Gracillariidae https://www.gracillariidae.net/species_by_code/DIPHOCHR ( ICZN Recommendation 74E). Examined specimens in Australia: New South Wales: Specimen 1(♂): Sydney , 33.8688°S 151.2093°E, 15-11-1932, male wing on slide 5676 T. Kumata 1991, male genitalia on slide 5676 T. Kumata 1991, ANIC slides: wings 11438; gen. 11439, leg. Goldfinch G.M. Specimen 2: the same locality data, 04-01-1933, without abdomen, Barcode of Life DNA voucher specimen, Sample ID: 11 ANIC-16231 , BOLD Proc.ID: ANICY231-11, leg. Goldfinch G.M., ID: 31 053802. Specimen 3: the same locality data, 16-11-1932, without abdomen, Barcode of Life DNA voucher specimen, Sample ID: 11 ANIC-16233 , BOLD Proc.ID: ANICY233-11, leg. Goldfinch G.M., ID: 31 053804. Specimen 4: the same locality data, 30-11-1932, without abdomen, leg. Goldfinch G.M. Specimen 5(♀): the same locality data, 25-11-1932, female wing on slide 5675 T. Kumata 1991, female genitalia on slide 5675 T. Kumata 1991, ANIC slides: wings 11440; gen. 11441, leg. Goldfinch G.M., ID: 31 081113. Specimen 6(♀): the same locality data, 15-11-1932, Barcode of Life DNA voucher specimen, Sample ID: 11 ANIC-1632 , leg. Goldfinch G.M., ID: 31 053803, DNA sample NULT023000, genitalia slide 6284, ANIC Acc. no 31 053803. Specimen 7(♀) ( Figs 151): National Park, NSW, 34.0736°S 151.0575°E, 17-02-1928, Goldfinch G.M., DNA sample NULT023125, genitalia slide 6285, ANIC Acc. no 31 085623, in ANIC (Canberra) .

Morphological diagnostic characterisation: Wingspan 6.4–7.4 mm; length of the forewing 3.0– 3.63 mm ( Fig. 151). Though Diphtheroptila ochridorsellum shares the general pattern of Diphtheroptila species like ochreous coloured dorsal sector with multiple oblique strigulae, curved or angulated fascia in sub-apical sector, nevertheless it is highly distinctive among other Diphtheroptila species, and especially those feeding on Glochidion plants ( Phyllanthaceae ). Internal structures of male and female genitalia as described below are highly diagnostic and linked specifically to Diphtheroptila ochridorsellum .

Head ( Figs 174–176): vertex shining white with ochreous intermixture on occiput, base of occiput dark ochreous, while erected and radially directed filiform scales of occiput tuft are dirty white; frons shining white, rather triangular in shape, maxillary and labial palpus shining white, the basal two labial palpomeres carry bunch of very long thickly hanging piliform scales—a characteristic feature for all Diphtheroptila species. In the case of D. ochridorsellum long brown hanging piliform scales strongly contrast from snowy white background colour of labial palpus; proboscis light ochreous and strongly rolled.

Thorax ( Figs 151, 180): white with light ochreous shading, tegula fuscous at basal half and dirty white, concolourous colour with thorax at apical half. Forewing slender narrow, equally broad along all its length—a characteristic trait for all Diphtheroptila species, but the wing pattern is diagnostic for Diphtheroptila ochridorsellum species: strigulae on dorsal margin rather thick, not grouped in groups of three as is the case for other Glochidion feeding Diphtheroptila species, they are fewer: four short strigulae in sub-basal sector of dorsal margin, two oblique longer strigulae meeting with coastal strigulae and forming either continuous or interrupted angulated fasciae, sub-apical margin is marked by a white thin edged with black scales fascia; a big, oval, very distinct apical spot present occupying a midpart of forewing apex, apical line fine, but distinct, black, as well as fringe line, gently running along the apical margin of the forewing, hindwing very narrow sharply pointed. Forewing with strongly sclerotised R 2, mid cell closed, R 3, R 4 well stalked with R 3, M 1 and M 2 are weak but clearly seen on apical margin, CuA1 is rather strongly sclerotised, but weaker than R 2, CuA 2 not detectable in this Australian species, CuP rudimentary, however the apical part is strongly sclerotised; in hindwing in males all veins are weak, hardly traceable, rudimentary except the very strong, long well and well sclerotised CuA. In females Sc is weak, Rs very strong and long terminating at sub-apical part of the hindwing, M 1 +M 2 forked, CuA very strong ( Fig. 180). Hind tibia with a row of short but sharp and erect small spines running along hind tibia and hind tarsomere I; hindleg uniformly fuscous dorsally, medial spurs exceptionally long, almost reaching the joint between tibia and tarsus with their tips.

Abdomen ( Figs 260, 270): The sclerotised margination of the abdomen is open. The margin of tergum II straight, apodemes on tergum II fine, long, slender, bases stronger sclerotised, distally very fine, straight, terminating at mid sector of tergum II; apodemes on sternum II short, almost 2× shorter when tergal apodemes, with pointed and sclerotised bases, straight, slender, distally, terminating with sharply pointed ends at posterior 1/4 of sternum II. Sternum VII in males with two narrow androconial sclerotised rings. Posterior margin of segment VI in females with broad, slightly diffuse sclerotisation.

Male genitalia (following the slide Grc 5676 in ANIC (Canberra)): tegumen rather strongly sclerotised, triangular with broad apical margins, pointed posteriorly, tuba analis moderate, membranous, well protruding, valvae complex consisting of two equally large parts, costal margin of valva sinuate, apical part dilating to more or less round cucullus very richly covered with long thin setae, saccular part well developed as a broad lobe with broad and truncate apical part, almost as long as valva; the distinctive diagnostic character is a strong hook-shaped sclerotisation which keeps both valval parts attached to each other; vinculum thick, semi-round with very short, protruding tubular saccus; aedeagus very short, broad, exceptionally strongly sclerotised, with a long suture like, stretching along almost the entire length of aedeagus cornutus, coecum weakly sclerotised, almost round, vesica with hook-like sclerotisation ending with sharp pointed arrow-like protrusion.

Female genitalia ( Figs 248, 249): papillae anales, moderate, oblong, united, covered with short setae, rather well sclerotised; apophyses posteriores and anteriores very short; apophyses posteriores just reach the posterior margin of segment VII, apophyses anteriores that initiate at the posterior margin of segment VII reach only posterior 1/3 part of segment VII; ostium bursae opening is situated at anterior margin of segment VII. The strongly diagnostic character is sterigma which consists of broad band on mid of segment VII, with two broadening posteriad sclerotised lobes surrounding the opening of ostium bursae; ductus bursae very short entirely covered by long lamellar strongly sclerotised colliculum, ductus seminalis initiates just beyond antrum, very narrow with rather broad, oval bulla seminalis, situated at about mid part of corpus bursae; corpus bursae very long, closed tubular, stronger sclerotised at posterior part carrying thin, prolonged, radially directed lines; signum small, but strongly sclerotised rhombusshaped, crossed with thin needle-like line at the middle.

Individual variation: There is a slight variation in the anterior posterior part of sterigmatic lobes, surrounding ostium bursae, they can be broader or narrower, also partly covered by melanised cuticula of sternum VII, hanging sinusoid-shaped lamella ante-vaginalis might slightly differ in shape, as well as sclerotisation on colliculum, though the general design of sclerotisation on colliculum follows the same pattern. The shape of signum and its position might slightly differ depending on how full the ductus bursae is with spermatophores.

BOLD data: https://www.boldsystems.org/index.php/Taxbrowser_Taxonpage?taxon= Diphtheroptila +ochridorsellu m&searchTax=Search+Taxonomy

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

GenBank data: No data.

Bionomics: Phyllanthaceae : Glochidion ferdinandii (Müll.Arg.) F.M. Bailey

Distribution: Australia: New South Wales ( Meyrick 1880: 167).