Saigusaia praegnans Wu et Niu

Niu, Xiaoling, Wu, Hong & Yu, Xiaoxia, 2008, Four new species of Saigusaia Vockeroth, 1980 (Diptera: Mycetophilidae) from China, Zootaxa 1741, pp. 24-30 : 27-28

Saigusaia praegnans Wu et Niu , sp. nov.

( Figs 3, 4 , 12)

Description. MALE. Lengths: Body: 3.96 mm; wing: 3.79 mm.

Head. Vertex and occiput blackish brown, with short black setae. Eye: Oval, with strong postocular bristles. Ocelli three, arranged horizontally, median ocellus smaller than laterals; lateral ocellus separated from median ocellus by about 2 times its own diameter and from eye margin by about 1/3 times its own diameter. Frons blackish brown, bare. Antenna: scape brown, pedicel and apical 3/4 first flagellomere dusk yellow, remainder of flagellomere brown. First flagellomere 3 times as long as wide, sixth flagellomere 3.25 times as long as wide. Face: brown, with several long setae; clypeus yellow, longer than head, with long scattered hairs; palpus yellowish, comprised of 5 segments.

Thorax. Mesonotum predominantly blackish brown, with yellow on shoulders. Arostichals ending before 1/3 of mesonotum, pair of pronotal bristles strong. Scutellum blackish brown, with 2 strong bristles. Mediotergite, blackish brown,bare. Proepisternum, meskatepisternum yellow. Mesanepisternum brown, laterotergite blackish brown. Metepisternum yellow.

Legs. Slender, predominantly yellow, ventral 1/3 of fore trochanter, entire mid and hind trochanters, ventral said of apical 1/6 of hind femora, basal 1/8 of hind femora brown. Leg ratios: t1:bt1= 1.4, t2: bt2=1.18, t3:bt3=1.66. Fore tibia with comb. Fore tibia with short bristles, mid tibia with four rows of long bristles and hind tibia with two rows of long bristles. The longest bristles about three times as long as tibial diameter. Tibial spurs yellow. Tarsal claws small. Empodia very small.

Wing. Slender, 3.0 times as long as wide and slightly deepened from 1/3 apical wing. R-stem, R1, R5, almost of M1, apical 2/3 of M2, apical 1/2 of CuA1, apical 1/2 of l CuA2 with dorsal setae. C slightly exceeding tip of R5, reaching to basal 1/4 point of wing margin between tips of R5 and M1. Point of furcation of CuA below base of r-m, Lengths of r-m 2.7 times as long as Rs, stem of median fork 2.4 times s long as r-m. Halter yellowish, with scattered long hairs at base.

Abdomen. Clothed with more long setae. Sternite I brown, bare. Tergites II–IV with narrow yellow posteromarginal band, remainder of tergites dark brown. Tergite VII and sternite VII about 3/4 as long as sclerites of segment VI. Tergite VIII about 1/2 as long as tergite VII. Sternites II–VII each with median and two pairs of sublateral fold-lines, sternite VIII with median fold-line. Tergite VIII about 3/4 as long as tergite VII. Sternite VIII about 2 times as long as tergite VIII.

Hypopgygium. Blackish brown. Tergite IX weakly broadened apically, with more moderate setae and several more strong and long bristles apically; sharply deflexed, narrowed towards apex, with apical emargination in two irregular triangular rows and bearing short spin-like setae; ventral parts of tergite IX strongly tapered. Gonostylus incurved, strongly swollen apically, with three rows of strong and moderate long spinelike setae on dorsal surface and more flattened thin spine-like setae on ventral surface at apex.

Remarks. Closest to S. monacanthus from Tianmushan Mountain in the color of the thorax, but can be easily distinguished by the ventral part of tergite IX being tapered (rhombic in S. monacanthus ) and the gonostylus broadened apically with no short black spine.

FEMALE. Unknown.

Types. Holotype (ZJFC 070412) CHINA: Zhejiang Tianmu Montain National Natural Reserve, 1090m, 14 November 1998, Mingshui, Zhao, Malaise trap. Paratypes (ZJFC 982421, 982422, 982431, 982428), same place and date as the holotype.

Etymology. The species epithet derive from the Latin praegnans = expanded, referring to the gonostylus swelled apically.

Figures

FIGURES 1 – 9, Male genitalia. 1. S. aberrans, sp. n., dorsal view. 2, S. aberrans, sp. n., ventral view (ceri and proctiger omitted). 3, S. praegnans, sp. n., dorsal view. 4, S. praegnans, sp. n., ventral view (ceri and proctiger omitted). 5, S. monacanthus, sp. n., dorsal view. 6, S. monacanthus, sp. n., ventral view (ceri and proctiger omitted). 7, S. spinibarbis, sp. n., dorsal view. 8, S. spinibarbis, sp. n., ventral view (ceri and proctiger omitted). 9, S. taiwan, dorsal view. Scale bar = 0.10 mm.