Myolepta diaphora, Mengual, 2022

Mengual, Ximo, 2022, New species of Myolepta Newman, 1838 (Diptera, Syrphidae) from the Indomalayan Realm, European Journal of Taxonomy 833, pp. 97-120 : 100-103

Myolepta diaphora sp. nov.

urn:lsid:zoobank.org:act:F6F8778E-41DE-4EDA-9AC1-399C386A0BCF

Fig. 3A–C

Diagnosis

Black, medium-sized species of Myolepta , with lateral white pruinosity on face, long facial sulcus and elongated postpedicel ( Fig. 3C ). Frontal prominence produced forward and vertex protuberant. Thorax and abdomen conspicuously punctate. Scutum mostly black, very lightly white pruinose except dense white pruinose on transverse suture and remarkable thick white hairs on notopleuron, posterodorsal anterior anepisternum, posterior anepisternum, anterior anepimeron and dorsal part of katepisternum. Wing largely bare basally, with vein R 4+5 with last section (petiole) shorther than crossvein h. Legs bicolorous ( Fig. 3A, C ). Abdomen constricted at the base of tergite 2, black with a golden tomentose fascia on the posterior margin of tergite 3, and tergite 4 with a medial patch of adpressed, longer, golden hairs ( Fig. 3A–B ).

Differential diagnosis

Myolepta diaphora sp. nov. can be distinguished from other species of Myolepta of the Indomalayan Realm by having the abdomen basally constricted (only M. petiolata has the abdomen petiolate, less than half its maximum width at its minimum), legs bicolorous (legs entirely pale yellow in M. splendens ) and elongated postpedicel. It differs from M. graciliventris by the face shiny medially (entirely golden pruinose in M. graciliventris ) and abdominal tergite 2 broader than long (tergite 2 longer than broad in M. graciliventris ). It is very similar to M. orientalis , but differs by having femora and tibia partly yellow (metallic bluish-black in M. orientalis ; Fig. 3D–E ), abdominal tergite 3 only with a narrow, dense golden pruinose fascia on posterior margin (tergite 3 black with a medial golden hairy vitta broadening posteriorly in M. orientalis ; Fig. 3D ), and tergite 4 black with a medial patch of adpressed golden hairs (tergite 4 black basally and orange on apical ⅓, completely covered with golden hairs in M. orientalis ; Fig. 3D ).

Etymology

From Greek ‘διάφορος’ (‘ diáphoros ’), meaning ‘different’ ( Brown 1956: 264). Species epithet is to be treated as an adjective.

Type locality

Laos: Houaphan Province, from Ban Saluei to Phou Pane Mts, 20.20° N, 103.99167° E –20.225° N, 104.01667° E, alt. 1340–1870 m.

Material examined

Holotype LAOS • ♀; Houaphan Province, from Ban Saluei to Phou Pane Mts; 20.20° N, 103.99167° E –20.225° N, 104.01667° E; alt. 1340–1870 m; 1 May–16 Jun. 2009; V. Kubáň and Lao coll. leg.; primary mountain forest, individual collecting; “Laos 2009 NHMB Basel and NMPC Prague exped.”; NMP; ZFMK- DIP-00082516 .

Description

MEASUREMENTS. Body: 8.0 mm; wing: 7.7 mm.

Female

HEAD ( Fig. 3C ). Face concave, without facial tubercle, black, shiny medially with very light white pruinosity, dense white pruinose laterally, with some scattered white hairs. White facial pruinosity does not reach antennal insertion level dorsally and expands towards oral margin ventrally, anterior to gena, but it does not reach the oral margin. Gena shiny black ventral to facial sulcus, white pruinose between facial sulcus and eye, with some scattered white pile. Lunule yellow. Frontal prominence conspicuous, produced forward. Frons black, with some scattered white hairs, depressed medially in the area above lunule with vertex protuberant; shiny on ventral ⅓, with two large golden-white pruinose maculae in middle ⅓, light white pruinose medially and dorsally until the anterior ocellus. Vertical triangle shiny black with yellow hairs. Eye bare, dichoptic. Antenna light brown except postpedicel black on dorsal ½ and yellow on ventral ½; postpedicel furry-like, rounded apically, slightly longer than broad, elongated, more than 2 × as long as broad. Arista bare, brown. Occiput covered with silvery pruinosity (except posterior margin of vertical triangle), with white hairs ventrally.

THORAX ( Fig. 3A–B ). Scutum black except postpronotum and postalar callus yellowish anteriorly and posteriorly, punctate, very lightly white pruinose except dense white pruinose on transverse suture, with adpressed, short white-yellowish hairs, which are thicker on the notopleuron. Scutellum rounded with preapical sulcus, punctate, with adpressed, short white-yellowish hairs, black except yellow preapical sulcus. Pleuron black, very lightly white-grey pruinose except densely white-grey pruinose on posterior anepisternum and medial and posterior parts of katepisternum, with thick white hairs on posterodorsal anterior anepisternum, posterior anepisternum, anterior anepimeron and dorsal part of katepisternum; katerpisternal hair patches broadly separated. Plumule yellow, very short. Metaepisternum and metasternum bare. Halter yellow, brownish basally. Posterior spiracular fringes dark brown.

WINGS. Membrane hyaline; pterostigma brown basally becoming hyaline apically; extensively microtrichose except cell c on basal ¾, cells r 1 and br anterior to RS bifurcation, and cells bm and cua on basal ¾. Spurious vein absent. Vein RS and basal section of R with black setulae dorsally. Cell r 4+5 closed very close to the wing margin; vein R 4+5 with last section (petiole) shorther than crossvein h ( Fig. 3A–B ).

LEGS. Coxae black except fore coxa yellow ventrally, densely grey pruinose. Fore and mid trochanter yellow; hind trochanter brown, yellow apically. Fore femur incrassate, yellow on basal 2 / 5 –½ and black on apical ½– 3 / 5, with yellow hairs and two rows of black setae on ventral side; fore tibia yellow on basal ¼, black on apical ¾, yellow hairy with black setulae on ventral side; fore basitarsomere yellow, yellow hairy; second fore tarsomere yellow on basal ¾ and black on apical ¼, yellow hairy; three apical fore tarsomeres black, black hairy. Mid femur slightly swollen, yellow on basal 2 / 5 and black on apical 3 / 5, with yellow hairs and two rows of black setae on ventral side; mid tibia on basal ¼, black on apical ¾, yellow hairy with black setulae on ventral side; two basal mid tarsomeres yellow, yellow hairy; apical with some black setulae; three apical mid tarsomeres black, black hairy. Hind femur incrassate, yellow on basal 2 /5 and black on apical 3 /5, with yellow hairs and two rows of black setae on ventral side; hind tibia yellow on basal ½, black on apical ½, yellow hairy with black setulae on ventral side; hind basitarsomere yellow, yellow hairy; second hind tarsomere yellow on basal ¾ and black on apical ¼, yellow hairy; three apical hind tarsomeres black, black hairy. All tibiae narrower basally and broader apically, remarkably hind tibia basally almost half as broad as apically.

ABDOMEN ( Fig. 3A–B ). Punctate, constricted basally with anterior margin of tergite 2 narrower than thorax (narrowest point of abdomen until posterior half of tergite 4). Tergite 1 black, lightly grey pruinose medially and densely grey pruinose laterally, white pilose. Tergite 2 black, with adpressed hairs that are black medially and white laterally, with long white hairs on anterolateral corner. Tergite 3 black, with narrow, golden tomentose fascia on posterior margin, with adpressed medially black and laterally white hairs, with narrow patch of adpressed golden hairs posteromedially, anterior to tomentose fascia. Tergite 4 black, with posterior margin dark brown, with adpressed black hairs except patch of adpressed, thicker, longer golden hairs in middle of tergite.

Remark

The holotype female was collected in primary mountain forest.

Figures

Fig. 3. A–C. Myolepta diaphora sp. nov., ♀, holotype (ZFMK-DIP-00082516). A. Habitus, lateral view. B. Habitus, dorsal view. C. Head, frontal view. D–F. M. orientalis Thompson, 1971, ♀, holotype (BPBM). D. Habitus, lateral view. E. Habitus, dorsal view. F. Head, frontal view. Scale bars: A–C= 1 mm.