Cryptonevra argenteum Riccardi, 2024

Riccardi, Paula Raile & Ang, Yuchen, 2024, New species and new records of Chloropinae from Singapore (Diptera: Chloropidae), Zootaxa 5458 (1), pp. 83-92 : 87-88

Cryptonevra argenteum Riccardi , sp. nov.

urn:lsid:zoobank.org:act:E5B35ED5-31FD-4F71-AACC-4A849E75E3B2

Figs. 3A–H

Type specimens. Holotype ♀ SINGAPORE, Pulau Semakau : New Mangrove Fragment ( SMN1 ), 1°12’03.100’’N, 103°45’45.400’’E, 1 m, Mangrove, Malaise trap, 18.x.2012, Mangrove Insect Project leg. ( ZRCBDP0089347 ) . Paratypes: 1 ♀ idem, except 28.xi.2013 ( ZRCBDP0090967 ) ; 1 ♀ idem, except Pulau Semakau: Old Mangrove Fragment ( SMO3 ) , 1°12’23.900’’N, 103°45’37.600’’E, 2 m, Malaise trap, 11.x.2012 ( ZRCBDP0091077 ) ; 1 ♀ idem, except 04.x.2012 ( ZRCBDP0089598 ; failed barcode) ; 1 ♂ idem, except Sungei Buloh Mangrove (SB10), 1°26’36.3’’N, 103°44’10.6’’E, 24 m, Malaise trap, 11.iv.2016 ( ZRCBDP0299705 ) ; 1 ♀ idem, except Pulau Semakau: New Mangrove Fragment ( SMN3 ) , 1°12’05.600’’N, 103°45’46.500’’E, 1 m, Malaise trap, 04.x.2012 ( ZRCBDP0089557 ; failed barcode) ; 1 ♀ idem, except Lim Chu Kang Mangrove ( LCK02 ) , 1°26’46.60’’N, 103°42’35.72’’E, 12 m, Malaise trap, 16.v.2018 ( ZRCBDP0306301 ; failed barcode) .

Diagnosis. Dark brown ground color; anepisternum entirely covered by silver pruinosity; black pilosity; scutellum mostly yellow; tarsi yellow; palpus long; surstylus with an M-shaped apex; mesolobus square.

Description Male. Body length 2.2–2.3 mm; wing length 1.55 mm. Body with dark brown ground color, black pilosity. Head. Ocellar triangle shiny, lateral edges straight, acute apically, without longitudinal sulcus; ocellar tubercle pruinose; gena linear, yellow; palpus extending beyond the anterior mouth margin, brown; postpedicel round, brown; arista bare, brown; seven short frontro-orbital setae; inner and outer vertical setae developed; ocellar seta short; postocellar setae cruciate, as long as outer verticals; frontal setulae short and scarce. Thorax. Scutum with ochre pruinosity; scutellum pale yellow except for the base; apical scutellar setae shorter than scutellum length, black; pleuron with anepisternum heavily slivery pruinose, katepisternum less heavily pruinose; 1+2 notopleural setae; halter with dark stem and whitish knob. Legs pruinose, dark with tarsi yellow; mid femur apex with a round extension on the external edge ( Fig. 3D ); tibial organ brown, concolorous with tibia. Wing with first and second sectors similar in length, R4+5 and M1 divergent; M1 faint posterior to dm-m; crossveins approximated, about dm-m length; anal lobe developed. Abdomen. Abdominal tergites dark brown. Male terminalia ( Figs. 3F–H ) with epandrium elongated dorsoventrally; surstylus with an M-shaped apex; mesolobus square; basiphallus short, with convex lateral edges; distiphallus without spines; postgonite with one pair of seta, slightly longer than pregonite.

Female. Similar to male, cercus dark brown.

Barcode. Cytochrome oxidase I (COI) partial-cds (313 b.p.; GenBank accession code OR776886) as follows:

A A A T A A AT G T T G G T A T A A A A T T G G AT C T C C T C C T C C A G C T G G A T - CAAAG AATGAAG TATT TA AATTTCGATCA GTTAATAATATTGTAATAGCTCCTG CTA ATA CA G G TAA A G A A A G TA ATA ATA G TATA G CCG TA ATTA CTAC A G ATC ATA CA A ATA G A G G TAT T CG AT CA A AT G TA AT T C CT G T T GAT C G TATATTA A TTACAGTAGTAATAAAATTTACTGCTCCTAAAATTGATGAAATTCCTGCTAAATGTAAAGAGAAAATTACTAAATCAACTGATGCCCCTCCATGAGCAATAATAGATGATAAA

Etymology. The specific epithet “argenteum ” is derived from Latin meaning silvery. This name refers to the silvery pruinosity of the anepisternum, a distinctive feature of the species.

Remarks. The ocellar triangle varies in length, occupying the entire frons or reaching ¾ of frontal length. Also, the apex of the tarsi varies from yellow to brown and the scutellum pilosity varies from black to pale. These features are considered intraspecific variations once the diagnostic features are invariable. The silvery anepisternum is better visualized in dry specimens ( Fig. 3A ) ( Ang 2023; https://singapore.biodiversity.online/species/A-ArthHexa-Diptera-000176). Unlike the remaining species of Cryptonevra ( Ismay 1994) , C. argenteum sp. nov. males do not have a femoral organ on the mid-femur.

In addition to the new species, this genus is being recorded for the first time in the Oriental region. Kanmyia’s (1983) key to Cryptonevra species from Japan, Ismay (1994), and Grochowska (2007) were used to confirm the identity of the new species. Cryptonevra argenteum sp. nov. was found in five different mangroves in Singapore, which indicates that its biology must be deeply associated with this type of habitat.

Distribution. Singapore *.

Figures

FIGURE 3. Cryptonevra argenteum sp. nov. diagnostic features. A, habitus (scale bar 1 mm). B, head and thorax dorsal, holotype. C, head dorsal, paratype. D, male mid femur apex; arrow points to an expansion. E, wing. F, male terminalia, profile. G, male terminalia, terminal view. H, hypandrium + phallic complex ventral, paratype (scale bar 0.1 mm). Abbreviations: an, anepisternum; ba, basiphallus; di, distiphallus; ep, epandrium; hy, hypandrium; me, mesolobus; ph, phallapodeme; ph sc, phallapodemic sclerite; pr, pregonite; po, postgonite; su, surstylus.