Mesorhaga laetitia, Santos & Capellari & Limeira-De-Oliveira, 2024

Santos, Ednaldo Bezerra Dos, Capellari, Renato Soares & Limeira-De-Oliveira, Francisco, 2024, Four new species of Mesorhaga Schiner (Diptera: Dolichopodidae) from Northeastern Brazil, with an identification key to South American species of the genus, Zootaxa 5519 (2), pp. 243-256 : 250-252

Mesorhaga laetitia sp. nov.

urn:lsid:zoobank.org:act:0B292899-7A19-4832-8AEA-E8FD75FF2447

( Figs 17–24 )

Etymology. From the Latin laetitia (happiness), following a historical trend in the genus taxonomy to refer to sadness or happiness feelings in the specific epithets.

Diagnosis. Specimens predominantly metallic blue with greenish and bronze reflections. Legs almost entirely yellow, tarsomeres 2–5 dark yellow to brown. Wing membrane ( Fig. 20 ) entirely hyaline; M 1 with smooth curve towards R 4+ 5 in about 1 / 3 distance between crossvein dm-m and wing apex; crossvein dm-m slightly short than distal section of M 4. Hypopygium ( Fig. 23 ): cerci dark yellow, robust, distal third slightly more sclerotized and distally widened, with dark setae on medial surface, group of strong distal setae ventrally and apical tuft of short setae internally in subtriangular projection.

Holotype ♂ ( Figs 17–22 ). Body length 3.33 mm, wing length 2.91 mm.

Variation. Male (n=6). Body length 2.70–3.48 mm, mean 3.10 mm, wing length 2.78–3.05 mm, mean 2.91 mm.

Head ( Figs 18, 19 ). Vertex deeply excavated; ocellar triangle with 1 pair of divergent, long and strong black ocellar setae, similar to notopleural setae; 2 pairs of divergent postocellar setae, short and weak, similar to presutural acrostichal setae; 3 postvertical setae, in line with row of postocular setae, inner and middle postvertical setae subequal in length and diameter, long and strong, as with presutural acrostichal setae; outer postvertical setae about 2.0X shorter and slightly weaker than inner and middle postvertical setae; 1 pair of strong vertical setae. Postocular near apex, short and uniseriate, longer and multiseriate from middle. Antenna brown to dark brown; scape, pedicel and postpedicel subequal in length; pedicel glabrous, with brownish-gray pruinosity, with ring of black distal setae, dorsal and ventral setae longer and stronger; postpedicel subrectangular, slightly wider than long; arista brown to dark brown, glabrous, about 3.0X length of scape, pedicel and postpedicel combined. Frons blue-green, face and clypeus with golden reflections and greyish-white pruinosity, denser on frons, around antenna and face. Face narrowing ventrally. Palpus yellow with strong distal seta, black and some additional smaller brown setae. Labellum yellow to dark yellow, yellow setae.

Thorax ( Fig. 21 ). Blue metallic with bronze reflections, setae black. Chaetotaxy: 3 pairs of acrostichal setae, 1 presutural seta, 2 postsutural setae as long and strong as dorsal pedicel setae; 1 + 4 dorsocentral setae, strong increasing in length and diameter posteriorly; 1 presutural intra-alar seta, as long and strong as presutural supra-alar (nearly on transverse suture); postpronotal lobe glabrous, except for very short seta, shorter than pronotal seta; 2 supra-alar setae, 1 presutural, as long and strong as presutural intra-alar; 2 notopleural setae, long and strong, subequal in length and diameter. Scutellum concolorous with mesonotum, with two pairs of macrosetae, 1st pair (lateral) slightly shorter and weaker than 2nd pair (apical). Pleurae dark blue with yellowish-gray pruinosity.

Legs ( Fig. 17 ). Yellow, except for mid and hind coxae, and tarsomeres 2–5 dark yellow to brown. Femora with elongated, pale setae on ventral surface, slightly shorter and sparse on fore femur, other surfaces with dark brown to black setae, these slightly longer on anterodorsal surface of fore femur and slightly stronger on 1 / 3 distal. Tibiae and tarsi setose; short setae, dark brown to black, slightly longer on proximal 1 / 2 of mid tibia. Fore leg: 32; 33; 14/ 11/ 5/ 3/ 2; mid leg: 25; 32; 23/ 8/ 6/ 4/ 2 and hind leg: 26; 27; 22/ 10/ 5/ 5/ 4.

Wing ( Fig. 20 ). Entirely hyaline, veins yellow, except for proximal 1 / 3 of vein R 1, dark brown to black; M 1 with smooth curve towards R 4+ 5 in 1 / 3 distance between crossvein dm-m and wing apex; crossvein dm-m slightly shorter than distal section of M 4. Lower calypter yellow, with fan of dark yellow to light brown setae. Halter dark yellow, knob yellow.

Abdomen ( Fig. 17 ). Robust, only slightly narrower than thorax, metallic blue with greenish and bronze reflections, brown sternites, dark brown to black setae, slightly longer and stronger on distal margins of tergites, distinctly longer and stronger on tergites 1 and 5 (series of 2 to 4, particularly longer, black on laterals of tergite 1); tergite 5 with long, strong black setae on lateroventral margin.

Male terminalia ( Fig. 23 ). Hypopygium brown.Hypandrium thin and elongated, slightly longer than epandrium. Epandrium elongate, subcylindrical, about 3.0X longer than wide, at maximum width; epandrial foramen oval, positioned on medial portion of epandrium; epandrial seta short and weak at base of epandrial lobe; epandrial lobe elongated, about 5.0X longer than wide, at maximum width with 2 setae, 1 medial long and strong, 1 subdistal short, weak, almost inconspicuous; surstylus with three lobes subequal in length: anterior lobe with distinct setae distally, this slightly shorter than median lobe; median lobe robust, narrowed towards apex, slightly longer than anterior lobe; posterior lobe slender and slightly longer than median lobe. Cerci symmetrical, robust, dark yellow, ventrally curved, 2 / 3 proximal weakly sclerotized, distal 1 / 3 slightly more sclerotized and distally widened; subproximal region with bifid appearance in lateral view; outer surface with dark setae, subequal in length, as long as medial seta of epandrial lobe, decreasing in length and diameter toward distal end; distal 1 / 3 with dark setae on medial surface, with group of strong distal setae ventrally and apical tuft of short setae internally on subtriangular projection.

Female. Unknown.

Type material. HOLOTYPE ♂ (pinned, good condition), deposited in CZMA: Brazil, PI [= Piauí], Piracuruca, P. [=Parque] N.[= Nacional] de Sete Cidades , Posto ICMBio , 04°05′57′′S / 41°42′34′′W \ Armadilha Malaise Gd [=grande], 1–15.i.2022, F. Limeira-de-Oliveira, D. Limeira & L.M.S. Cardoso, cols [=coletores] \ FLO 6770 . PARATYPES: same data as holotype, except: FLO 6769 (pinned, terminalia in glass microtube, good condition: 1♂, CZMA) ; idem, \ FLO 6768 (1♂, CZMA) ; idem, \ FLO 6767 (1♂, CZMA) ; idem, \ FLO 5731 (1♂, CZMA) ; idem, \ FLO 9675 (1♂, CZMA) .

Distribution. Brazil: Piauí.

Remarks. Mesorhaga laetitia sp. nov., keys out to couplet 10 and Mesorhaga nayaritensis Bickel in Bickel (2007), but can be differentiated by having the brown to dark brown antenna and subtriangular postpedicel (black antenna and a subcircular postpedicel in M. nayaritensis ), predominantly yellow legs, except for the brown mid and hind coxae (predominantly yellow legs, except all the brown coxae in M. nayaritensis ), epandrial lobe has two setae, one seta medial and one seta subdistal (epandrial lobe has two setae subdistally in M. nayaritensis ), hypandrium without apical expansion process (hypandrium with apical hood slightly expanded in M. nayaritensis ), cercus has apical subtriangular projection (cercus without apical subtriangular projection, distal 1 / 3 clavate in M. nayaritensis ).

Figures

FIGURES 17–24. Mesorhaga laetitia sp. nov., Holotype ♂, left lateral view. 17, habitus, left lateral view; 18, head, left lateral view; 19, head, frontal view; 20, wing; 21, thorax, dorsal view; 22, post-abdomen, left lateral view; 23, terminalia left lateral view; 24, terminalia illustration left lateral view.