Saigusaia monacanthus 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 : 28-29

Saigusaia monacanthus Wu et Niu , sp. nov.

( Figs 5, 6 , 13)

Description. MALE. Lengths: Body: 4.20 mm; Wing: 3.94 mm.

Head. Vertex and occiput blackish brown, with short black setae. Eye: oval, with strong prostocular bristles. Ocelli three, lateral ocellus separated from median ocellus by about 2 times its own diameter and from eye margin by about 1/2 time its own diameter. Frons blackish brown, bare. Antenna: Scape brown; pedicel and first flagellomere, apicla 1/2 of second flagellomere yellow, remainder of the flagellomere brown; each flagellomere subequal, first flagellomere and sixth flagellomere about 3 times as long as wide. Face: brown, with scattered long setae. Clypeus yellow, longer than the head, with scattered long hair. Palpus: yellowish, 5 palpomeres.

Thorax. Mesonotum predominantly blackish brown, yellow on shoulders. Arostichals ending before 1/3 of mesonotum, pair of pronotal bristles strong. Scutellum blackish brown, with 4 strong bristles. Mediotergite, blackish brown, bare. Proepisternum, meskatepisternum yellow. Mesanepisternum, laterotergite brown. Metepisternum yellow.

Legs. Slender, predominantly yellow, ventral 1/3 of fore trochanter, almost entire mid and hind trochanters, ventral said of apical 1/6 of hind femora, basal 1/8 of hind femur brown. Leg ratios:t1:bt1= 1.60, t2:bt2=1.22, t3:bt3=1.69.Fore tibia with comb and short bristles, mid tibia with four rows of long bristles and hind tibia with three 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, about 3.2 times as long as wide; slightly deepened from 1/3 apical wing. R-stem, R1, R5, almost of M1, apical 1/2 of M2, apical 1/4 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. Length of r-m 3.0 times as long as Rs, stem of median fork 1.7 times as long as r-m, M1 1.2 times as long as M2. Halter yellowish, with scattered long hair at base.

Abdomen. Clothed with dense long setae. Sternite I brown, bare. Tergites II–IV with a narrow yellow posteromarginal band, remainder of tergites darkish brown. Tergite VII and sternite VII about 3/4 as long as scleriters of segment 6. Tergite VIII about 1/2 as long as tergite VII. Sternites II–VII with pair of submedian fold line and two pairs of sublateral fold lines. Tergite VIII only with submedian fold line.

Hypopgygium. Blackish brown, Tergite IX broadened apically, with more moderate setae and 6 strong and long bristles apically; sharply deflexed, with apical emargination in two subquadrate rows and bearing short spinose setae; ventral parts of tergite IX broad. Gonostylus slightly swollen at apex, with strong black spine on the dorsal surface beyond 1/2 of gonostylus.

Remarks. This species is closest to Saigusais praegnans from Tianmu Moutain (Zhejiang Province) based upon color of the thorax, but can be easily distinguished by a spine on the dorsal surface of the gonostylus, the shape of the ventral parts of tergite IX rhombic (strongly tapered in S. praegnans ).

FEMALE. Unknown.

Types. Holotype (ZJFC 982427) CHINA: Zhejiang Province Tianmushan National Natural Reserve, 1090m, 14 November1998, Mingshui Zhao, Malaise trap. Paratypes (ZJFC 982425, 982426, 982430, 982028), same place and date as the holotype.

Etymology. The species epithet derive from the Latin monacanthus = single spine, referring to gonsotylus with one short spine on the dorsal surface.

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.