Chaethippus flavus, Riccardi, 2020

Riccardi, Paula Raile, 2020, Taxonomic revision of the genus Chaethippus Duda, 1930 (Diptera: Chloropidae) with the description of four species, Zootaxa 4802 (1), pp. 129-140 : 134-135

Chaethippus flavus sp.nov.

( figs. 15–19 )

urn:lsid:zoobank.org:act:D51B182C-9CDA-4AF6-8FBA-F9A838138E85

Material examined. Holotype ♂ FRENCH GUIANA, Mitaraka , MIT-E-savane roch 2, 2°13’59.8”N 54°27’46.5”W, 471 m, 13–20.viii.2015, Malaise trap (6m), Pierre Henri Dalens leg. [ MNHN].

Diagnosis. Tibial spur absent; one vibrissa; three pairs of prescutellar setae; pleuron completely yellow, anepisternum bare; fore coxa with 2 stout spines anteriorly.

Description. Body length, 1.4 mm. Wing length, 1.3 mm.

Head ( figs 16–17 ). Wider than long dorsally and higher than long in profile, entirely yellow except for black ocellar tubercle and a black spot on the ocellar triangle. Head and thoracic setae black. Frons slightly longer than wide, lateral margins subparallel, front margin straight. Ocellar triangle pruinose, extending to two thirds length of frons, posterior margin two thirds width of frons, lateral margins slightly concave, apex acute, macula brownish. Eye oval, long axis slightly oblique. Face slightly longer than high; facial carina width as wide as aristal base, reaching the frontoclypeal suture; antenna yellow, postpedicel reniform, as high as long, entirely yellow; arista yellowish on the basal 1/3 and black apically, with short pubescence, about two and half times as long as postpedicel; gena slightly wider than length of postpedicel, rather curved inwards; one vibrissa; occiput yellow, ventrally with a M-shaped black mark; proboscis yellow; palpus yellow, small, equal in length to antenna, slightly curved upwards, with brown setulae; oral margin not protruding; clypeus yellow. Thorax ( fig. 15 ). Scutum quadrate, yellow, stripes indistinct; scutum densely pruinose with dark setulae; one posterior dorsocentral seta developed, longer than outer vertical seta; a row of six prescutellar setae; postpronotal lobe yellow with one long seta equal to notopleurals and prescutellars; postalar seta developed, about as long as dorsocentral seta. Pleuron bare, yellow, anepisternum pollinose. Scutellum yellow pruinose, convex on the disc, with black setulae, wider than long, slightly triangular apically; apical scutellar seta with separation equal to that of posterior ocelli and as long as length of scutellum; two pairs of lateral setae developed, as long as dorsocentrals; post-scutellum brown, shining. Wing. Hyaline with pale brown veins covered in sparse brown microtrichia; costal sections 1–4: 8: 12: 7.5: 4; veins R 4+5 and M 1 almost parallel; distance between r-m and dm-m about four times length of r-m. Halter pale yellow. Legs ( figs. 15, 17 ). Entirely yellow; fore coxa pilose anteriorly, with a strong seta basally and a less distinct seta apically; femoral organ rounded with a brownish spot and three rows of spines; hind tibia with preapical spur absent; posterior tibial organ short and oval, occupying less than half of tibia length, orangish. Abdomen ( fig. 15 ). As in the generic diagnosis. Male terminalia ( figs. 18–19 ). Remnant of the 6th sternite quadrate. Epandrium wider than long, surstylus long, with parallel margins and lower margin slightly constricted basally; cercus as long as wide, with two small lobes, with one very long seta. Hypandrium weakly sclerotized, closed; basiphallus cylindrical; distiphallus short, and membranous, striate; pre- and postgonite fused, clavate, sensory pores and setae not observed; phallapodemic sclerite rounded; phallapodeme short, not bifid apically; sperm pump not observed. Female terminalia. Unknown.

Etymology. The specific epithet “ flavus ” is a Latin adjective, meaning yellow. It refers to the completely yellow coloration of the thorax.

Remarks. Only the species Chaethippus carioca and C. flavus do not have a hind tibial spur. Despite this, the remaining external diagnostic features and the general pattern of the male terminalia are similar to the remaining species of Chaethippus leading no doubts about the generic placement of both species.

Figures

FIGURES 15–19. Chaethippus flavus sp.nov. holotype. 15, habitus (scale bar 1 mm). 16, head in dorsal view. 17, femoral organ. 18, male terminalia in ventral view. 19, male terminalia in terminal view (scale bar 0.1 mm). Abbreviations: bas, basiphallus; cer, cercus; dis, distiphallus; ep, epandrium; gon, gonite; st 6, remnant of the 6th sternite.