Pseudacteon linzhiensis, Liu & Disney, 2022

Liu, Guang-Chun & Disney, R. Henry L., 2022, Revision of the ant-parasitizing genus Pseudacteon Coquillett (Diptera, Phoridae) from China, Zootaxa 5138 (3), pp. 201-237 : 224-225

13. Pseudacteon linzhiensis sp. nov.

( Figs. 17A–F , 25G–H )

Diagnosis. Female. Apical seta shorter than maximum width of palpus; tarsomere 5 a very little longer than tarsomere 1; setal palisade 2/3 length of mid tibia; setulae below basal half of hind femur shorter than those of anteroventral row of outer half; tergite VI reduced to a narrow anterior strip in middle but each lateral quarter bears 2 long and 2 short setulae at posterior margin; sternite VI divided into two triangular plates, which bear 3 long setulae each side; dorsum of oviscape with about 6–7 minute setulae each side; venter of oviscape with 4–5 minute setulae.

Female. Body length 1.40–1.42 mm. Frons brown, with 14–16 setulae. Supra-antennal setae as strong as adjacent frontal setae, upper pair being higher on frons than lower fronto-orbital setae. Lower interfrontal seta directly under lower fronto-orbital seta. Second row of frontal setae clearly concave, with upper interfronal setae further from each other than either is from upper fronto-orbital seta. Flagellomere 1 brown and subglobose. Palpus brownish yellow, with 6 long setae, apical one shorter than maximum of width of palpus, but longer than adjacent setulae. Labrum and labella pale yellow.

Thorax brown. Scutellum with two pairs of setae, posterior twice length of anterior. Legs brown, with foreleg being paler. Ratios of lengths of the fore tarsomeres about 0.96: 0.70: 0.68: 0.61: 1, with all five bearing setal palisades ( Fig. 17B ). Dorsal setal palisade extends 2/3 length along mid tibia ( Fig. 17C ). Setae below basal half of hind femur a little shorter than those of anteroventral row of outer half, but of similar thickness ( Fig. 17D ). Wing ( Fig. 17A ) length 1.58 mm, width 0.76–0.79 mm, width/length 0.50. Costal index 0.39–0.40. Costal ratios 1.31: 1, second section with 6–7 dorsal setulae. Costal cilia 0.076–0.077 mm long. Costa with 15–16 dorsal setulae. Alula with 2 setae. Veins brown, membrane brownish gray. Haltere pale brown.

Abdominal tergites brown and tergites 1–5 with sparse minute setulae on posterior margins. Tergite VI ( Fig. 17F , 25G ) reduced to a narrow anterior strip in middle but each lateral quarter bears 2 long and 2 short setulae at posterior margin. Venter brown. Sternite VI ( Fig. 17E , 25H ) divided into two triangular plates, each with 3 long setulae each side. Oviscape brown and arched. The dorsum of the oviscape with about 6–7 minute setulae each side. The venter of the oviscape with 4–5 minute setulae ( Fig. 17E ).

Male. Unknown.

Distribution. China (Xizang).

Etymology. The species epithet refers to the type locality.

Specimens examined. Holotype. ♀, China: Xizang, Linzhi, Chayu, Chawalong (28°29′8.81″N, 98°25′34.0968″E; 1988m), 20-Aug-2020, Guangchun Liu.

Remarks. The new species is similar to P. yunnanesis sp. nov., but different from the latter by longer second section of costa and the shape of sternite VI. In the key to Russian Far East ( Disney & Michailovskaya 2000), the species runs to couplet 4 on page 44, to female of P. pullum Michailovskaya, 1995 , it differs from the latter by the apical seta shorter than the maximum width of palpus, palisade extending 2/3 of mid tibia and abdominal sternite VI bifurcate with 3 long setae on each lower branch.

Figures

FIGURES 17A–F. Pseudacteon linzhiensis sp. nov., female. A. wing, dorsal view; B. fore tarsus, anterior view; C. mid tibia, posterior view; D. hind femur, anterior view; E. ovipositor, ventral view. F. tergite VI, dorsal view. Scale bar = 0.1mm.

FIGURES 25A–J. Tergite VI and sternite VI of females. A–B. P. rudisetosus Disney et Michailovskaya; C–D. P. pullum Michailovskaya; E–F. P. obtusatus Liu et Cai; G–H. P. linzhiensis sp. nov.; I–J. P. shennongjianus sp. nov. Scale bar = 0.1mm.