A Study of the Genus Limnophora Robineau-Desvoidy (Diptera: Muscidae), with Descriptions of Six new species from China

This paper provides the characters of genus Limnophora (Diptera: Muscidae) and a key to the Chinese species of Limnophora, six new species collected from Hainan Island of China, namely, L. brevispatula, n. sp., L. cothurnosurstyla, n. sp., L. dyadocerca, n. sp., L. longitarsis, n. sp., L. nuditibia, n. sp. and L. ypocerca, n. sp. are diagnosed, described and illustrated, a new record species in China, namely, L. argentifrons (Shinonaga et Kano, 1977), is also included.


Introduction
Limnophora Robineau-Desvoidy is a large genus of Muscidae (Diptera). Robineau-Desvoidy established the genus in 1830, with L. palustria as the type species. This genus has a worldwide distribution, according to recent data, there are approximately 230 species in the world, including 66 species and a subspecies in China. In recent years, many scholars collected Muscidae specimens from Hainan Island of China, including six new species and a new record species belong to genus Limnophora. Hainan Island belongs to Oriental regions, and located on the northwest of the South China (18°10 -20°9 N, 108°36 -112°2 E), it with a tropical moist monsoonal climate, and has many mountain ranges, valleys, streams and rivers, the various environments and special climate are fit for Limnophora species to live.

Materials and Methods
Specimens were collected from Hainan Island of China. They were examined using an Olympus SZ-ST stereomicroscope (www.olympus.com); further details (dissection, drawing, etc.) were studied under an Motic SMZ-140 dissecting stereomicroscopes. Male and female genitalia were examined and illustrated after they were dissected from the fly's bodies, all illustrations were drawn on ink jet plotter paper. The genitalia of dissected specimens were mounted in glycerol in a plastic tube on the staging pin.

Head.
Eye bare; frons about 1.2 times as wide as postpedicel, about 1/10 of head in width, lower 3/5 of frons with 5-6 pairs of intilted ori, upper 2/5 with 3 pairs of thin ors, frontal vitta black, about 1.5-2.0 times as wide as fronto-orbital plate, ocellar seta longer than the longest ori, fronto-orbital plate and parafacial covered with gray white pruinosity, parafacial about 2/5 of postpedicel in width; antennae black, postpedicel about 3.0 times as long as wide, arista short ciliated, the longest hair shorter than aristal basal diameter, lunule brown, frontal angle situated behind vibrissal angle in profile; gena about 1/8 of eye in height, genal and postgena hairs all black, the upper lateral area of the occiput with black hairs, prementum shining, about 3.0 times as long as wide; labella small, the length subequal with prementum height, palpus black, slightly longer than prementum.
Thorax. Black in ground color, proepisternum covered with gray pruinosity distinctly, scutum black mostly, lateral of anterior of transverse suture to notopleuron covered with gray pruinosity, anterior part of transverse suture covered with gray pruinosity, anterior 3/4 of postscutum with black transverse stripe, posterior margin of transverse stripe extending to back, but not reaching to scutoscutellar suture; 4 rows of trichoid prst-acr, only 1 pair distinct before scutellum, dc 2+3, ia 0+1, pra hair-like; scutellum all black, lateral and ventral surface bare; basisternum of prosternum with hairs, notopleural, proepisternum hollow in centre, anepimeron, meron and katepimeron all bare; proepisternal setae 2, upper anterior anepisternal seta 1, katepisternal setae 1+2, the lower one only about 1/3 of the upper one.
Wing. Transparent slightly, veins brown, basicosta black, costal spine small and short, distal of Sc slightly straight, dorsal and ventral surface of R 4+5 vein in basal part and rascial node all with setae, calypters light brown, its margin brown, lower calypter protrude to tongue-shaped; halter yellow.
Legs. Entirely black; fore tibia without median p; mid femur without av, basal 2/5 with setiform a, the super-medial one strong, 2 apical pd, with 2 pv, mid tibia with 1 median p; hind femur with 2 av in apical 1/3, without pv, hind tibia with 1 median av, 1 supermedial ad, without pv; mid and hind tarsi longer than tibia, claw and pulvilli short and small, about half of 5th tarsomere in length.
Abdomen. Black in ground color, oviformshaped, covered with brownish-gray pruinosity, tergites 3 and 4 with a pair of triangulare lateral spots respectively, the widest part of spot wider than the length of tergite, tergite 5 with a trapeziform median spot indistinctly, syntergite 1+2 black except lateral of posterior part with brownish-grey pruinosity, sternite 1 bare. Tternite 5, cerci and surstyli as in Figure  Remarks. --This new species is similar to L. longitarsis n. sp., but it differs from the latter in male frontal angle situated behind vibrissal angle in profile; fore tibia without median p, mid femur with 2 p; the surstyli like a short spoon in profile.
Etymology. --The species name is derived from the Latin "brev" meaning short, "spatula" meaning spoon, refering to surstyli short spoon-shaped in profile. Head. Eye bare; frons about 1/5 of head in width, lateral margins paralleled, with 4 pairs of ori, 2 pairs of thin ors, frontal vitta black, about 4.0 times as wide as fronto-orbital plate, frontal triangle narrow, adjacent to frontal angle, ocellar seta shorter than the the lower ori, inner vertical seta long and strong, outer vertical seta about 2/3-4/5 of inner vertical seta in length, upper 2/3 of fronto-orbital plate covered with brown pruinosity, lower 1/3 covered with brown grey pruinosity, parafacial narrow, covered with light grey pruinosity, middle part of parafacial about 1/3 of postpedicel in width; antennae black and long, distal of postpedicel reaching to epistoma almost, basal situated upper 3/5 of eye, postpedicel about 3.0 times as long as wide, arista short ciliated, the longest hair subequal with aristal basal diameter; vibrissal angle at the same vertical line with frontal angle in profile; gena about 1/10 of eye in height, covered with grey pruinosity, genal and postgenal hairs all black, the upper lateral area of the occiput with hairs, prementum shining, about 3.0 times as long as wide; labella small, the length subequal with prementum height, palpus black, slightly longer than prementum.
Wing. Transparent slightly, veins brown, basicosta black, costal spine small or absent, distal of Sc slightly straight, dorsal and ventral surface of rascial node with setae, calypters yellowish, lower calypter protrude to tongueshaped; halter yellow.

Legs.
Entirely black; fore tibia without median p; mid femur without av, basal 1/2 with setiform a row, 2 super-medial a long and strong, 2 pre-apical pd, 2 bassal pv, mid tibia with 2 median p; hind femur with 2-3 av in apical 1/3, without pv, hind tibia without av, with 1 medial ad, without pv; all tarsi longer than tibia, pulvilli small, about half of claw in length, claw about 3/5 of 5th tarsomere in length.
Abdomen. Black in ground color, oviformshaped almost, covered with dark gray to brownish-gray pruinosity, tergites 3 and 4 with a pair of big black lateral spots respectively, the widest part of spot wider than the length of tergite, tergite 5 with 1 wide median patch, syntergite 1+2 all black except middle part, tergite 5 only discal scutellar setae and posterior marginal scutellar setae distinctly, tergite 6 and sternite 1 bare, posterior margin of sternites 2 to 4 with a pair of long setae respectively. Sternites 2-5, cerci and surstyli as in Figure 3A-E.
Female. -Unknown. Remarks. --This new species is similar to L. malailei Emden, 1965, but it differs from the latter in male frons about 1/5 of head in width, frontal vitta black; lateral of anterior of transverse suture covered with gray pruinosity stripe; calypters yellowish; hind femur with 2 bassal pv, hind femur with 2-3 av in apical 1/3, hind tibia without av; abdomen oviformshaped.
Etymology. --The species name is derived from the Greek words "cothurn" meaning boot, "surstylus" meaning surstyli, refering to the surstyli boot-shaped in posterior view. Head. Eye bare; frons black, upper part about 0.52 times as wide as head, lower part about 0.43 times as wide as head, with 2 pairs of ori, almost in the same length, with 1 forewards hair in its upper, with 1 pairs of ors, a short and proclinate hair always in the lower part, upper part of frontal vitta about 8.0 times as wide as fronto-orbital plate, frontal triangle unobvious, reaching to upper 1/3 of ors at most; outer vertical seta about half of inner vertical seta, inner vertical seta slightly longer than ocellar seta, ocellar seta slightly longer than the ori, fronto-orbital plate covered with dark brown pruinosity, parafacial covered with light grey pruinosity, the width of parafacial about half of postpedicel in width; antennae black brown, postpedicel long and broad, about 3.0 times as long as broad, and its width subequal with length of pedicel, basal 1/6-1/5 becoming wide, most aristal hairs subequal with its basal diameter; vibrissal angle situated behind frontal angle in profile; gena covered with dense and dark grey pruinosity, genal hairs black and sparse, genal height about 1/5 of width of postpedicel at most, and about 1/12 of eye height, the upper lateral area of the occiput with hairs, prementum shining, about 2.2-2.5 times as long as wide; labella small, the length subequal with height of prementum, palpus black, slightly longer than prementum.
Thorax. Black in ground color, most part of scutum black, proepisternum covered with dark gray pruinosity, anterior 1/3 of prescutum covered with dark gray pruinosity, and with a black median vitta obviously, posterior 2/5 of postscutum covered with gray pruinosity, and with 3 narrow brown vittae, all vittae reaching to scutoscutellar suture; postpronotal lobe and its posterior part covered with grayish-white pruinosity, scutellum all black; 2 rows of trichoid prstacr, dc 2+3, without obvious ia and pra, basisternum of prosternum with hairs, notopleural, lateral of scutellum, proepisternum hollow in centre, anepimeron, meron and katepimeron all bare; proepisternal setae 2, upper anterior anepisternal seta 1, katepisternal setae 1+2, lower one about 2/5 of anterior one in length, anterior and posterior spiracles small and brown.
Wing. Slightly transparent, veins brown, basicosta black, costal spine absent, dorsal and ventral surface of rascial node with setae, calypters grayish-white, posterior margin of lower calypter dark brown, knob of halter big and black, stalk black brown.
Legs. Entirely black, femur thin and long; fore tibia without median p; mid femur without av, basal half without distinct a row, with 1 preapical pd, apical 3/5 with distinct pv, mid tibia with 1 median p; hind femur with 1 apical av, without pv, hind tibia with 1 av, with 1 medial ad, without pv; all tarsi longer than tibia, pulvilli small, about half of claw in length, claw about 3/5 of 5th tarsomere in length.
Abdomen. Black in ground color, coneshaped, syntergite 1+2 black mostly, tergites 3 and 4 with a pair of dark brown triangular spots respectively, tergite 5 with indistinct small lateral spots, middle and lateral of tergites 3 to 5 covered with light gray pruinosity, sternite 1 bare, posterior margin of sternite 5 narrow, cerci split to four forks ( Figure 4B), inner two forks pointed, outer two long and broad, distal of surstyli hookshaped and bend forwards. Sternite 5, cerci and surstyli as in Figure 4A-C. Remarks. --This new species is similar to L. ypocerca n. sp., but it differs from the latter in male upper part of frontal vitta about 8.0 times as wide as fronto-orbital plate, frons with 2 pairs of ori; thorax without obvious ia; calypters grayish-white, posterior margin of lower calypter dark brown, knob of halter big and black, stalk black brown; mid femur with 1 pre-apical pd; abdomen cone-shaped, cerci split to two parts (four forks), inner two forks pointed, outer two long and broad, distal of surstyli hook-shaped and bend forwards.
Etymology.--The species name is derived from the Greek words "dyad" meaning two, "cerca" meaning cerci, refering to cerci split to two parts. Head. Eye bare; frons about 1.2-1.3 times as wide as postpedicel, about 1/10-1/9 of head in width, frontal vitta black, about 2.0 times as wide as fronto-orbital plate, lower 3/5 of frons with 5-6 pairs of intilted ori, lower 2/5 with 3 pairs of thin ors, the ocellar seta longer than the longest ori, upper part of fronto-orbital plate covered with brownish-gray pruinosity, the lower part and parafacial covered with grayish-white pruinosity, parafacial about 2/5 of postpedicel in width; antennae black, postpedicel about 3.0 times as long as wide, arista short ciliated, the longest hair subequal with aristal basal diameter; lunule brown, vibrissal angle situated behind frontal angle in profile, gena about 1/8 of eye in height, genal and postgena hairs all black, the upper lateral area of the occiput with black hairs; prementum shining, about 3.0 times as long as wide; labella small, the length subequal with prementum height, palpus black, slightly longer than prementum.
Wing. Transparent slightly, veins brown, basicosta black, costal spine small and short, distal of Sc slightly straight, dorsal and ventral surface of R 4+5 vein in basal part and radial node all with setae, calypters yellowish, lower calypter projecting and tongue-shaped, halter yellow.
Legs. Entirely black. Fore tibia with 1 median p, tartus of front legs about 1.8-1.9 times as long as fore tibia; mid femur without av, basal 2/5 with setiform a row (one of them large on super-medial), 2 pre-apical pd, without obvious pv, ventral surface with a long seta basally, mid tibia with 1 median p; distal 1/3 of hind femur with 3-4 av, without pv, hind tibia with 1 median av, 1 super-medial ad, without pv. Mid and hind tarsi longer than tibia, fore pulvilli subequal with claws in length, mid and hind pulvilli shorter than claws, claws about 1/2 of 5 th tarsomere in length.
Abdomen. Black in ground color, similar to oviform-shaped, covered with brownish-grey pruinosity, tergites 3 and 4 with a pair of triangular lateral spots respectively, the distance between the lateral spots about 1/3 of the length of tergite, the widest part of spot wider than the length of tergite, tergite 5 with a trapeziform median spot indistinctly, syntergite 1+2 black except lateral of posterior part with brownish-grey pruinosity, sternite 1 bare. Sternites 2-5, cerci and surstyli as in Figure 5A-C.
Female. --Frons about 1/3 of head in width, with 4 pairs of intilted ori, outer with small setae, with 2 pairs of ors, frontal triangle reaching to front of frons, frontal vitta about 4.0 times as wide as fronto-orbital plate, fronto-orbital plate and parafacial covered with gray white pruinosity, parafacial about 2/5 of postpedicel in width, vibrissal angle at the same vertical line with frontal angle in profile; ia 0+1(2); tartus of front legs about 1.6-1.7 times as long as fore tibia; tergites 3 and 4 with a pair of triangular lateral spots, the distance between the lateral spots about 1/5 of the length of tergite, syntergite 1+2 almost black, a pair of tergites 6 and 7 respectively, all long and strong, posterior margin of tergite 6 wide, with a gap in middle of tergite 6, but not cloven, sternites 7 and 8 divide into 2 parts, sternite 7 with a seta, tergites 6 to 8 extend to ventral surface, tergite 8 with 2 setae, hypoproct with many dense and long setae, cerci broad and large, 3 spermathecas, surface 1/3 transparent and membranous, but not sunken. Spermatheca and ovipositor as in Figure 5D, F-G. The other characters are the same as male. Remarks.
--This new species is similar to L. albonigra Emden, 1965, but it differs from the latter in male parafacial about 2/5 of postpedicel in width; thorax with 4 rows of prst-acr, calypters yellowish, tartus of front legs about 1.8-1.9 times as long as fore tibia, mid femur without distinct pv, hind tibia with 1 median av, hind femur with 3-4 av, without pv; syntergite 1+2 black except lateral of posterior part with brownish-grey pruinosity.
Etymology. --The species name is derived from the Latin words "long" meaning long and "tarsis" meaning tartus, referring to tartus of front legs long, about 1.8-1.9 times as long as fore tibia. Head. Eye bare; frons about 2/5 of head in width, with 2 pairs of intilted ori, upper 2/5 with 2 pairs of upper ors, frontal vitta black, about 5.0 times as wide as fronto-orbital plate, frontal triangle shining, reaching to frontage of frons, ocellar seta longer than the longest ori, fronto-orbital plate and parafacial covered with dark gray pruinosity, lower part of parafacial became narrow obviously, parafacial about 1/3 of postpedicel in width, which only wirelike in profile; antennae black, wide and large, distal of postpedicel reaching to epistoma almost, postpedicel about 3.0 times as long as wide, arista short pubescent, the longest hair subequal with aristal basal diameter; lunule dark black, vibrissal angle at the same vertical line with frontal angle or slightly situated behind in profile; gena about 1/8 of eye in height, genal and postgena hairs all black, the upper lateral area of the occiput with black hairs, prementum shining, about 2.5 times as long as wide; labella small, the length subequal with prementum height, palpus black, slightly longer than prementum.
Wing. Transparent, veins brown, basicosta black, costal spine small and short, distal of Sc slightly straight, dorsal and ventral surface of rascial node with setae, upper calypter yellowish, lower calypter white and protrude to tongue-shaped; halter yellow. Legs. Entirely black; fore tibia without median p; mid femur without av, basal part with setiform a row, the super-medial one strong, with 1-2 pre-basal pv, 2 pre-apical pd, mid tibia with 1 super-medial p; hind femur with 2 av in apical 1/4, with 1 super-medial pv and 1 sub-basal pv, hind tibia without av, with 1 super-medial ad, without pv; each tarsi longer than tibia, pulvilli and claw small, shorter than half of 5th tarsomere.
Abdomen. Abdomen as in Figure 6A. Black in ground color, short oviform-shaped, covered with brownish-gray pruinosity, tergites 3 and 4 with a pair of short and flat triangular lateral spots respectively, dark black, the width of spot about 2.0 times as long as the tergite, tergite 5 with triangular median spot, dark brown, syntergite 1+2 all black, sternite 1 bare. Sternites 1-5, cerci and surstyli as in Figure 6B-D, F.
--This new species is similar to L. subplumosa Emden, 1965, but it differs from the latter in male frontal vitta about 5.0 times as wide as fronto-orbital plate, parafacial about 1/3 of postpedicel in width, arista short pubescent; hind tibia without av.
Etymology. --The species name is derived from the Latin "nud" meaning bare and "tibia" meaning tibia, refering to hind tibia of the male without av.

Head.
Eye bare; frons about 4/9-1/2 of head in width, with 3-4 pairs of small and short ori, 1 pair of retroverted ors, frontal vitta black, about 3.5 times as wide as fronto-orbital plate, covered with dark brown pruinosity, frontal triangle reaching to anterior 3/4 of frons, ocellar seta about 2.0 times as long as the longest ori, posterior vertical seta long and strong, about 4.0 times as long as the longest ori, outer vertical seta short and small, slightly longer than postocellar seta, fronto-orbital plate and parafacial covered with grey pruinosity, parafacial about half of postpedicel in width; antennae black, postpedicel about 3.0 times as long as wide, about 2.5 times as long as pedicel, basal 1/3 of arista becoming wide, aristal hairs slightly short, mostly hairs longer than aristal basal diameter; vibrissal angle situated behind frontal angle in profile; gena covered with caesious pruinosity, genal hairs black and sparse, genal height about 2/7 of eye height, the upper lateral area of the occiput with hairs, proboscis thin and long, prementum shining, about 3.5 times as long as wide; labella small, the length subequal with height of prementum, palpus thin and long, only distal part slightly intumescent, and covered with light grey pruinosity distally, subequal with prementum in length.
Wing. Slightly transparent, veins brown, basicosta black, costal spine small or absent, dorsal and ventral surface of rascial node with setae, calypters yellowish, lower calypter protrude to tongue-shaped; halter yellow.

Legs.
Entirely black, but all coxae, trochanters and femora covered with caesious pruinosity; fore tibia without median p; mid femur without av, basal half with setiform a row, with 2 pre-apical pd, 1-2 basal pv, mid tibia with 1 median p, apical v long and strong; hind femur with 1-2 pre-apical av, without pv, hind tibia with 1 submedial av, 1 medial ad, without pv; all tarsi longer than tibia, pulvilli small, about half of claw in length, claw about 3/5 of 5th tarsomere in length. Figure 7A. Black in ground color, wide and oviform-shaped, covered with gray to light gray pruinosity, tergites 3 to 5 with narrow and light median vitta, tergites 3 and 4 with broad and dark brown spots respectively, tergite 5 with long strip-shaped lateral spots, sternite 1 bare, posterior margin of sternite 5 wide, without long seta, distal of surstyli intumescent in profile, cerci with an small subcercal structure hidden behind the distal half of cercal plate ( Figure 7C-a). Sternite 5, cerci and surstyli as in Figure 7B-E. Remarks. --This new species is similar to L. rufimana Strobl, 1893, but it differs from the latter in male frons about 4/9-1/2 of head in width; thorax with 2-3 trichoid prst-acr rows; mid femur without av, mid tibia with 1 median p; distal of surstyli intumescent in profile, a small subcercal structure hidden behind the distal half of cercal plate.

Abdomen. Abdomen as in
Etymology. --The species name is derived from the Greek words "ypo-" meaning sub-, "cerca" meaning cerci, refering to distal half of cercal plate with a small subcercal structure.