Five new species of subgenus Plesiominettia (Diptera, Lauxaniidae, Minettia) in southern China, with a key to known species

Abstract Five species of the subgenus Plesiominettia Shatalkin from the southern China are described as new to science: Minettia (Plesiominettia) flavoscutellata sp. n., Minettia (Plesiominettia) longaciculiformis sp. n., Minettia (Plesiominettia) nigrantennata sp. n., Minettia (Plesiominettia) tridentata sp. n. and Minettia (Plesiominettia) zhejiangica sp. n. One species, Minettia longistylis Sasakawa, is transferred to the subgenus Plesiominettia from Minettia s. str. A key to separate the known species of the subgenus is presented, along with a taxonomic list of species. The type materials of the new species are deposited in the China Agricultural University, Beijing, China (CAUC).

There are 20 known species distributed in the Palaearctic and Oriental regions in the subgenus Plesiominettia, eight of which have been found in China.

Materials and methods
The general terminology follows Cumming and Wood (2009) and Gaimari and Silva (2010). Line diagrams were drawn using a drawing tube attached to a Nikon SMZ 1500 stereomicroscope and to a Nikon 80i compound microscope. Photographs were taken by a Nikon DS-Fi2-U3 digital camera mounted on a Nikon SMZ 1500 stereomicroscope. Genitalia preparations were made by removing and macerating the apical portion of the abdomen in cold saturated NaOH for six hours, then soaking in distilled water with a few drops of glacial acetic acid. After examination, the genitalia were transferred to glycerin and stored in a microvial pinned below the specimen. Specimens examined were deposited in China Agricultural University, Beijing, China (CAUC). Type specimens (see Appendix) are from the following museums: Head black. Face slightly concave, yellowish brown to blackish brown except black ventral margin, parafacial yellow except black inner margin, with a narrow pale brown medial stripe. Frons blackish brown except yellow anterior margin; ocellar triangle black; ocellar setulae developed, longer than anterior fronto-orbital setae, anterior fronto-orbital setae reclinate, shorter than posterior fronto-orbital setae. Gena yellow, approximately 1/6 height of eye. Antenna with scape brown and pedicel brownish yellow, 1 st flagellomere entirely blackish brown on outer edge but yellow on basal 1/4 on inner edge; 1 st flagellomere nearly 1.6 times longer than high; arista black, except yellow at base, short plumose; rays of arista with longest setulae as long as 1/2 height of 1 st flagellomere. A blackish brown spot present between eye and base of antenna. Proboscis and palpus black.
Remarks. The new species is different from other species of the subgenus in the scutellum being yellow except blackish brown on basal 1/4-1/3 and the surstylus having a long falcate process in lateral view. The 1+1 female spermathecae is distinctive from the other species of the subgenus.
Distribution. China (Hubei).  Etymology. Latin, Longi-is from the Latin, longus, meaning long; -acicula is the diminutive of the Latin noun acus, meaning needle, or pin; -formis is from the Latin forma, meaning shape; referring to the surstylus with 2 pairs of long needle-like processes; a feminine adjective.

Minettia
Diagnosis. Body yellow. Mesonotum with anteriormost dorsocentral setae situated midway between transverse scutal suture and scutoscutellar suture. Legs yellow, except brown at tip of tibiae and tarsomeres 3-5 pale brown; hind tibia with one weak preapical anterodorsal seta. Male genitalia: surstylus with a pair of long needle-like processes in lateral view; phallus round apically with a pair of long processes curved upward in ventral view. Female sternite eight confluent with tergite 8, projecting on posterior margin with dense setae.
Head yellow. Frons with ocellar triangle yellow; ocellar setulae developed, longer than posterior fronto-orbital setae, anterior fronto-orbital setae reclinate, shorter than posterior setae. Face with sparse grayish white pollinosity, without spot; gena about 1/5 height of eye. Antenna entirely yellow, 1 st flagellomere 1.7 times longer than high; arista black except yellow at base, pubescent; rays of arista with longest setulae slightly shorter than 1/3 height of 1 st flagellomere. Proboscis yellow except brown tip and palpus brownish yellow.
Thorax yellow with sparse grayish white pollinosity. Mesonotum with 0+3 dorsocentral setae (anteriormost dorsocentral setae situated midway between transverse scutal suture and scutoscutellar suture), acrostichal setulae in eight rows; a pair of long acrostichal setulae present in front of prescutellar setae, prescutellar setae shorter than 1 st postsutural dorsocentral setae; one strong intra-alar seta and one weak intra-alar seta situated at almost equal intervals on line between supra-alar setae and posterior dorsocentral setae; one anepisternal seta, two katepisternal setae. Scutellum yellow. Legs yellow except brown at tip of tibiae and tarsomeres 3-5 pale brown. Fore femur with six posteroventral setae and nine posterodorsal setae, fore tibia with 1 short preapical anterodorsal seta and one short apicoventral seta. Mid femur with eight anterior setae and one apical posterior seta; mid tibia with one strong preapical anterodorsal seta and two strong apicoventral setae. Hind tibia with one weak preapical anterodorsal seta and one short apicoventral seta. Wing (Fig. 44) slightly yellow, pale brown along costal margin and a brown stripe on dm-cu; costa with 2 nd (between R 1 and R 2+3 ), 3 rd (between R 2+3 and R 4+5 ) and 4 th (between R 4+5 and M 1 ) sections in proportion of 5.5:1.5:1; r-m at middle of discal cell; ultimate and penultimate sections of M 1 in proportion of 1:1.5; ultimate section of CuA 1 approximately 1/10 of penultimate. Halter yellow.
Remarks. The new species differs entirely from other species of the subgenus in the surstylus having a pair of very long needle-like processes and the phallus being brown, longer than 1/2 length of abdomen in ventral view.
Distribution. China (Zhejiang). Diagnosis. Arista pubescent, rays of arista with longest setulae shorter than 1/3 height of 1 st flagellomere. Mesonotum with anteriormost dorsocentral setae slightly beyond suture. Legs black, except basal tip of tibia yellow, fore tarsus brown, mid and hind tarsomeres 1-2 dark yellow and tarsomeres 3-5 brown; hind femur with a row of anteroventral seta on apical half. Male genitalia: surstylus consisting of a brown knife-like apical process and a yellow bar-like apical process with setulae in lateral view; postgonite narrow basally and broad contorted apically with 2 short setulae; phallus very broad, columnar, with a pair of inner sclerites and a row of tiny spinule, visible in dorsal view.

Minettia
Description. Male. Body length 4.6 mm, wing length 5.0 mm. Head blackish brown. Frons with narrow yellow margin; ocellar triangle grayish black; ocellar setulae developed, slightly longer than anterior fronto-orbital setae, anterior fronto-orbital setae reclinate, shorter than posterior fronto-orbital setae. Face and parafacial dark black; gena approximately 1/6 height of eye. Antenna blackish brown, 1 st flagellomere 1.6 times longer than high; arista black, except pale brown at base, pubescent, rays of arista with longest setulae shorter than 1/3 height of 1 st flagellomere. A blackish brown spot present between eye and base of antenna. Proboscis blackish brown and palpus black.
Abdomen blackish brown with sparse brownish pollinosity, subglossy. Male genitalia : syntergosternite 7+8 semicircular with a pair of dorsal setulae; epandrium broad with long dorsal setae in lateral view; surstylus consisting of a brown knife-like apical process and a yellow bar-like apical process with setulae in lateral view; hypandrium slightly V-shaped, hypandrial apodeme very small; postgonite narrow basally, broad and contorted apically, with two short setulae; phallus very broad columnar, ventral sclerite narrow apically and slightly shorter than dorsal sclerite, and medial membranous section beyond base of phallus sclerites, with a pair of inner sclerites and a row of tiny spinule, visible in dorsal view; phallapodeme short, Y-shaped, slightly projecting forward.
Female. Unknown. Latin, tri-, meaning three, + dentata, meaning toothed; referring to a pair of subuliform inner sclerites of the phallus each with 3 acute apical teeth; a feminine adjective Diagnosis. Antennal scape blackish brown, pedicel yellow, 1 st flagellomere yellow except upper and apical edges black and brown on apical half; rays of arista with longest setulae shorter than 1/4 height of 1 st flagellomere. Mesonotum with anteriormost dorsocentral setae slightly beyond suture. Legs black, except mid and hind tibiae dark yellow on basal 2/3 and tarsomeres 3-5 blackish brown. Male genitalia: surstylus broad triangular in lateral view, with a tiny acute process and a small triangular apical process in ventral view. Female sternite eight confluent with tergite 8, sternite 9 narrow triangular apically and slightly curved. Head blackish brown. Frons with narrow yellow margin; ocellar triangle grayish black; ocellar setulae developed, slightly shorter than anterior fronto-orbital setae, anterior fronto-orbital setae reclinate, shorter than posterior fronto-orbital setae. Face dark black and parafacial grayish black. Gena approximately 1/5 height of eye. Antennal scape blackish brown and pedicel yellow, 1 st flagellomere yellow except upper and apical edges black and brown on apical half, 1 st flagellomere 1.4 times longer than high; arista black, with microscopic setulae, and rays of arista with longest setulae shorter than 1/4 height of 1 st flagellomere. A blackish brown spot present between eye and base of antenna. Proboscis blackish brown and palpus black.
Abdomen blackish brown with sparse brownish pollinosity, subglossy. Male genitalia : syntergosternite 7+8 semicircular with a pair of dorsal setulae; epandrium narrow basally with long setae and broad apically; surstylus broad triangular in lateral view, with a tiny acute process and a small triangular apical process in ventral view; hypandrium slightly V-shaped, hypandrial apodeme short; postgonite slender with a triangular medial process and two subapical setulae and one apical setula in ventral view; phallus broad columnar, with a trapezial basal process and a pair of subuliform inner sclerites each with three acute apical teeth, and medial membranous section beyond base of phallus in ventral view; phallapodeme short, Y-shaped, slightly projecting forward. Female sternite 8 confluent with tergite 8, sternite 9 narrow triangular apically and curved slightly; spermathecae 1+2, round with short brown stem (Figs 36-38).
Remarks. The new species is very similar to Minettia (P.) nigrantennata sp. n. from China (Hunan) in the following characters: body blackish brown; frons with yellow anterior margin and face dark black; thorax black to blackish brown with dense brownish pollinosity, mesonotum with 0+3 dorsocentral setae (anteriormost dorsocentral setae slightly beyond suture) and prescutellar setae as long as 1 st postsutural dorsocentral setae; wing slightly dark yellow; abdomen blackish brown with sparse brownish pollinosity, subglossy. It can be separated from the latter by the yellow antennal 1 st flagellomere , except upper and apical edges being black and brown on apical half; the legs being black, except mid and hind tibiae being dark yellow on basal 2/3. In Minettia (P.) nigrantennata, the antennal 1 st flagellomere is blackish brown and the legs are black, except basal tip of tibia is yellow, mid and hind tarsomeres 1-2 are dark yellow.
Abdomen black with grayish white pollinosity. Male genitalia (Figs 21-25): syntergosternite 7+8 circular with a long irregular ventral process and many dorsal setulae; epandrium slender, slightly projecting at anterior ventral corner; surstylus with a curved aciculiform inner process and a geniculate outer process, acute apically; hypandrium inverted-U shape, hypandrial apodeme very short; postgonite short claviform in ventral view; phallus broad at middle, three acute processes and many spinules on membranous section in ventral view and slender and round apically in lateral view; phallapodeme small, projecting forward. Female sternite 7 rectangular and sternite 8 semicircular; spermathecae 1+2, nearly rounded and stem brown at base (Figs 39-40).
Remarks. The new species is similar to Minettia (P.) longistylis Sasakawa from China (Taiwan) in size (large), mesonotum brown with grayish pollinosity, a pair of long acrostichal setulae present in front of prescutellar setae. It can be separated from the latter by the arista being short plumose, the rays of arista having longest setulae as long as 1/2 height of antennal 1 st flagellomere; the mesonotum having acrostichal setulae in eight rows; the mid tibia having two posteroventral setae; the surstylus having a curved aciculiform inner process and a geniculate outer process, acute apically. In Minettia (P.) longistylis, the arista is pubescent and the rays of arista have longest setulae as long as 1/4 height of antennal 1 st flagellomere; the mesonotum has acrostichal setulae in ten irregular rows; the mid tibia has one posteroventral seta; the surstylus is very long (Sasakawa 2002).