Orthonevra cthulhu Miranda, Soares & Thompson, 2024

Miranda, Gil F. G., Soares, Matheus M. M. & Thompson, Christian, 2024, The Neotropical Orthonevra Macquart, 1829 (Diptera: Syrphidae), Zootaxa 5484 (1), pp. 1-78 : 22-24

Orthonevra cthulhu Miranda, Soares & Thompson sp. nov.

98-4. Thompson 2006: 21 (key reference).

Orthonevra 3 (FCT notes)

Figs 9 and 10 . Map: Fig. 39

Diagnosis. Similar to O. argentina and O. flukei but O. cthulhu has a short sub-apical vitta in cell r1.

Description. MALE. Head ( Fig. 9d–f ): metallic bluish green, face with convexity on dorsal 1/ 2 in profile and ventral 1/4 slightly produced anteriorly as a convexity, strongly regulose except medially between convexity and anterior oral margin, pile white and scale-like; with white microtrichose subtriangular macula laterally, positioned immediately ventral to level of antennal base but far removed from it. Antenna brownish yellow, post-pedicel darker apically; pedicel twice the length of the scape, postpedicel oval elongated, slightly longer than the length of the pedicel. Mala slightly produced apico-ventrally, smooth. Gena shiny, smooth, and with white pile. Frontal triangle shiny, regulose, with a medial longitudinal sulcus starting on the eye contiguity and ending dorsal to the elevation of the lunule, with sparse white pile, scale-like laterally. Vertical triangle isosceles triangle-shaped, 4 × the length of the eye contiguity, metallic green, bare except for dark erect pile on ocellar triangle; ocellar triangle equilateral, making up 2/3 of the vertical triangle. Occiput not visible laterally on dorsal 1/2, ventral 1/2 homogeneously covered with white microtrichia which gets longer dorsal to the gena, with a row of inconspicuous dark pile that becomes longer and white close to the gena. Eyes holoptic; with a sub-anterior sinuous vitta, a sub-anterior circle dorsally, a strongly sinuous middle vitta, and an uninterrupted medial fascia, eyes darker on anterior margin and on ventral 1/2 of posterior margin, anterior margin connected dorsally and ventrally to sub-anterior vitta (ventral to dorsal circle).

Thorax ( Fig. 9d–f ): metallic green, pile white, short, mostly appressed and sparsely distributed, bare on dark areas; scutum with four complete and separate dark matte vittae, that taper anteriorly, with purple reflections intermixed, sub-medial vittae slightly interrupted at transverse sulcus, and with a short narrow lateral vittate macula posterior to transverse sulcus; notopleuron metallic green with a dark matte area dorsal; scutellum mostly dark metallic green, apical margin of a different lighter hue, with short, appressed, white pile. Pleuron with white pile on antepronotum, proepisternum, posterior anepisternum, on dorsal and ventral patches on katepisternum, anterior anepimeron, and katatergum, mostly with sparse microtrichia. Calypter white with white marginal pile, ventral lobe with longer marginal pile. Plumule white and long. Halter yellowish-white.

Legs ( Fig. 9e, f ): metallic green, except brownish tibiae with paler base and apex, and tarsi with first two (three on metatarsus) tarsomeres yellow, remaining brown. Legs covered with short white pile, with black ventral setulae on mesotarsus, metafemur, and apex of mesotibia, shorter, paler and sparser laterally on pro and metatarsus.

Wing ( Fig. 9e ): hyaline, with dark vitta sub-apically (from end R2+3 until posterior end of M1), and dark apex (but fading posterior to vein R4+5), and dark vittate macula sub-apically on cell r1, a fasciate pair apically on r4+5 and a small fasciate macula antero-apically on dm ( Fig. 9e ), microtrichose except bare medially on cell bm and immediately posterior to pseudovein; basicosta with dense appressed pale to dark pile, with two more prominent black setae apically. Alula 2 × the width of cell c.

Abdomen ( Fig. 9e ): metallic green, terga matte black microtrichose sub-laterally, pile sockets as small protuberances, pile white, appressed and very short; sterna metallic green, with longer white appressed pile; sternum 4 with right side more extended than left.

Genitalia ( Fig. 10c–e ): surstylus bent in a 90° on the basal 1/3, and directed more dorsally, base slightly expanded and with a shallow concave notch on dorsal surface, with a rounded apex slightly directed ventrally, with very short inconspicuous pile ( Fig. 10c ); subepandrial sclerite arms widened towards apex; cercus triangular, with acute corners, with distinct pile. Hypandrium compressed medially, with anterior ventral notch through 1/2 the length of the hypandrium, notch with a carina on each side ( Fig. 10d ); postgonites rectangular but apex produced as a tapering extension and directed ventrally and slightly medially, pile concentrated on dorsal corner before the extension, baso-median surface forms a carina that ends dorsally in a short triangular projection; phallus hooked apically, widened medially, basal tubular process directed ventrally.

Variation. Some specimens with tibiae mostly metallic brownish-green; one specimen from Goiás has a short triangular projection medially on the surstylus.

FEMALE ( Fig. 10a, b ). Like male except: head metallic green, face with slight convexity in profile; frons with medial longitudinal sulcus starting anterior to the ocellar triangle and extending throughout 2/3 of the length of the frons; vertex small, metallic green but with purple reflections lateral to ocellar triangle; ocellar triangle occupying most of the vertex; occiput not visible laterally on dorsal 1/3, ventral 2/3 homogeneously covered in white microtrichia which gets longer dorsal to the gena, with very inconspicuous pile on dorsal 1/3, with a few sparse pile on ventral 1/4; eyes do not form circle antero-dorsally; tergum 5 wholly metallic. Genitalia: Tergum 7 as two rectangular sclerotized areas. Sternum 7 as a sclerotized strip with pile on apical margin. Tergum 8 sub-triangular with two heavier sclerotized fasciate areas. Sternum 8 large, baso-lateral margins concave, apical margin with large medial ‘V-shaped’ indentation and a sub-lateral concave indentation on each side, wholly pilose. Sternum 9 as half-oval, sclerotized and distinct plate, with medial internal long sclerotized tube connected to the genital opening medially on sternum 9. Epiproct flattened, sub-rectangular, convex apical margin, with two short baso-lateral apodemes, sparsely pilose. Cercus oval, pilose on apical 1/2, positioned ventro-laterally to epiproct. Hypoproct mostly membranous, with triangular shaped sclerotized area, wholly pilose.

Length. Body 4.25–5.10mm (n=4), wing 3.60–4.00mm (n=4); female 4.71–5.52mm (n=5), wing 3.50–4.10mm (n=5).

Distribution. Brazil (Ceará, Espírito Santo, Goiás, São Paulo and Rio Grande do Sul) and Paraguay ( Fig. 39 ).

Altitudinal range. 160–830m.

Etymology. The specific epithet is derived from the name of an ancient cosmic entity from the work of H.P. Lovecraft, and alludes to the exquisite eye marking pattern on the males (when viewed from the front) of this species that resembles the description of the entity in that work. It should be treated as a noun in apposition.

Comments. This species is restricted to central Brazil and Paraguay and to altitudes lower than 1000m.

Type material examined: BRAZIL. Espírito Santo, Baixo Guandu [ca 19°31'20.9"S 41°01'11.0"W], ??. ix.1970, P. C. Elias (male holotype cthulhu MZUSP, USNMENT 00028638) .

Paratypes examined: BRAZIL . Ceará, Ubajara, Parque Nac. de Ubajara, Cachoeira do Cafundó , 03°50'13"S 40°54'35"W, Armadilha Malaise, 1–14.ii.2013, J.A. Rafael & F. Limeira-de-Oliveira (1 female CZMA) ; Ubajara, Parque Nac. de Ubajara, Cachoeira do Cafundó , 03º50'13"S 40º54'35"W, Armadilha Malaise, 18–30.xi & 16– 31.xii.2012, F. Limeira-de-Oliveira & J.S. Pinto Júnior (4 females CZMA) ; Espírito Santo, Baixo Guandu [ca 19°31'20.9"S 41°01'11.0"W], ??. ix.1970, P. C. Elias (2 males MZUSP, USNMENT01492702–3 ) ; Goiás, Varjão, Chácara N. Sra. Aparecida [ca 17°03'45.4"S 49°38'39.3"W], Armadilha Luminosa, 29.vii.2019, Col. Lopes, W.R. (4 males INPA) ; São Paulo, Barueri [ca 23°29'35.1"S 46°54'28.8"W], 25.ii.1961, K. Lenko (1 male MZUSP, USNMENT01492704 ) ; Orida Verda [sic. Onda Verde, ca 20°35'40.8"S 49°17'22.4"W], Faz. Sao Joao, ??. i.1946, (1 female MZUSP, USNMENT01492711 ) ; Rio Grande do Sul, Esmeralda , 27°55'10.2"S 51°20'33.9"W, iv. ix.2021 (1 male, photographic record) [https://www.inaturalist.org/observations/93639307]. PARAGUAY. Distrito Capital , Assuncion [ca 25°14'41.4"S 57°34'17.3"W], Villa [Nova], 25.xi.[19]05, J.D. Anisits (1 male ZMHU, USNMENT01492690 ) .

Figures

FIGURE 9. Orthonevra cthulhu sp. nov. a–c. Female: a. Head and thorax, dorsal view. b. Habitus lateral. c. Head, lateral view. d–f. Male: d. Head and thorax, dorsal view. e. Habitus lateral. f. Head, oblique dorsal view. Abbreviations: sc: scale-like pile; scl: scutellum; r1v: sub-apical vitta of cell r1.

FIGURE 10. Orthonevra cthulhu sp. nov., genitalia. a. Female, dorsal view. b. Female, ventral view. c–e. Male: c. Epandrium, lateral view. d. Hypandrium, lateral view. e. Phallus, lateral view. Abbreviations: btp: basal tubular process; cerc: cercus; hypc: ventral carina of the hypandrium; hypo: hypoproct; epi: epiproct; pg: postgonite; sur: surstylus; s7 & 8: sterna 7 & 8; t7 & 8: terga 7 & 8.

FIGURE 39. Distribution map for Orthonevra argentina (Brèthes, 1922), O. batman sp. nov., O. chilensis Thompson, 1999, O. cthulhu sp. nov., O. quadristriata (Shannon & Aubertin, 1933), O. roseae sp. nov., O. shannoni (Curran, 1926), and O. thompsoni sp. nov.