Megaselia setidifferitatis, Liu & Chen, 2019

Liu, Guang-Chun & Chen, Gao, 2019, New Scuttle flies (Diptera: Phoridae) reared from dead Termite, Odontotermes formosanus (Shiraki, 1909) (Isoptera: Termitidae) in China, Zootaxa 4551 (2), pp. 237-243 : 239-242

Megaselia setidifferitatis sp. nov.

( Figs. 10–17 )

Diagnosis. Labella with only a few (about 15) pale spines below; Total number of SPS about 30, diameter, 0.008– 0.009 mm; Mesopleuron bare; notopleuron with two bristles and without cleft; scutellum with a posterior pair of bristles and an anterior pair of hairs (male) or two pair of bristles (female); hypopygium brown and anal tube pale brown; left side of epandrium with 8–10 hairs and a long bristle; wing costal index 0.43 (male) and 0.44 (female); abdominal tergites uniformly pale brown; Dufour’s crop mechanism oval, with two arms.

Description. Male ( Fig. 10 ). Frons brown, a little broader than long, with 90–100 hairs, dulled by dense microtrichia. Antial bristle closer to eye margin than to median furrow. Lower Supra-antennal bristles smaller than upper pair. Postpedicel subglobose, brown, diameter a little less than half frontal width. SPS densely distributed around postpedicel, from base to about level of insertion point of arista. Diameter small to medium (0.008–0.009 mm). Arista brown. Pubescence of third aristomere about as long as diameter of basal segment. Sensilla at base of third aristomere usually well separated. Palps yellow, with 7 bristles and some hairs. Proboscis with pale yellowish labrum and labella. Prementum with two pairs of hairs. Width of labrum about two third of pedicel. Labella with 5 pseudotracheae, 15–20 spinules and some longer hairs on lower face. Thorax pale brown, to brown on top. Mesopleuron bare, notopleuron with two bristles and without cleft. Rest of scutum with a post-alar and prescutellar dorsocentral briste each side. Scutellum with a posterior pair of bristles and an anterior pair of hairs. Abdominal tergites I–VI light brown. Tergites with sparse hairs except for a few longer ones at rear margin of tergite VI. Venter pale grey. Hypopygium ( Fig. 12 ) brown and anal tube pale brown. left side of epandrium with 8–10 hairs and a long bristle. Cerci with 6–8 hairs, which shorter than terminal bristles of proctiger. Legs yellow, with brownish patch at tip of hind femur. Fore tarsus slender, with postero-dorsal hair palisade on all five segments. Ratios of lengths of front tarsal segments ca. 3.75: 1.24:1:0.86:1. Near-dorsal palisade of mid tibia extends two-thirds of length, and with 7–8 differentiated postero-dorsal hairs behind this palisade. The row of 8 hairs below basal half of hind femur include some that are a little, but distinctly longer than longest hairs of antero-ventral row of outer half. Hind tibia with 12 differentiated, almost spine-like, postero-dorsal hairs. Spines of apical comb of posterior face all simple. Wing ( Fig. 11 ) length 1.098 mm. Costal index 0.43. Costal ratios 3.39: 1.31: 1. Longest costal cilia 0.052– 0.055 mm long. Sc fully developed and reaching R 1. Hair at base of Rs weak (0.034–0.036mm). Axillary ridge with two hairs, the longer one being longer than costal cilia. Weins pale brown, with costa being little darker and vein A 1 +CuA 2 pale greyish brown and obscure at base. Vein M 1 originaes beyond fork of Rs. Membrane lightly, but distinctly tinged yellowish brown. Haltere pale brown.

Female ( Fig. 13 ). Similar to male but differs at follows: Frons with 95–110 hairs. Labrum stronger than in male, about as broad as postpedicel. Scutum with 2 pairs of bristles, which anterior pairs 1/2 as long as posterior ones. All abdominal tergites ( Figs. 16 ) uniformly pale brown, tergiteVsquare, tergite VI longer than wide ( Fig. 17 ). Dufour’s crop mechanism oval, with two arms ( Fig. 15 ). Rectum with 4 rectal papillae. Wing ( Fig. 14 ) length 1.325mm. Costal index 0.44. Costal ratios 3.50: 1.29:1. Costal cilia 0.052–0.055 mm.

Etymology. the species name refers to difference of scutellar bristles between male and female.

Material examined. Holotype. ♂, China, Jiangsu, Nanjing, The Arboretum of Nanjing Forestry University (30°05′1.6″N, 118°48′51.77″E; 525 m), 19–Apr–2018, Yue-Qin Wang ; Paratype: 12 ♂, 14 ♀, same data as holotype .

Remarks. In the keys of Borgmeier (1967) this species will run out at couplet 14 on page 93, to M. patellipyga Borgmeier,1967 . It is different from the latter by the detail of hypopygium, wing index and ratios and the number of ventral hairs of hind femur. The female will run to couplet 22 of group VI on page 85, to M. chipmanni Borgmeier,1967 , which is only known in female. It can be distinguished from latter by its very long tergiteVI, number of ventral hairs of hind femur and wing costal ratios. In the key of Disney (1989) the species runs to couplet 177 on page 30, to M. hendersoni Disney, 1979 , it is distinguished from latter by no notopleural cleft, labella not enlarged and sparse spines, and detail of hypopygium. In the key of Buck & Disney (2001), the new species runs out at couplet 21 on page 82 to M. trojani Disney , but the latter has three axillary bristles, longer hairs on rear of tergite VI and a differentiated bristle on left epandrium.

Figures

FIGURES 10–17. Megaselia setidifferitatis sp. nov. 10–12. male; 13–17. female. 10. body lateral view; 11. wing; 12. hypopygium; 13. body lateral view; 14. wing; 15. Dufour’s crop mechanism; 16–17. Abdominal tergites. Scale bar = 1 mm (Figs 10,13); scale bar = 0.5 mm (Figs 11,14); scale bar=0.1 mm (Figs 12,15–17).