Pseudacteon tianmuensis, 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 : 231-232

18. Pseudacteon tianmuensis sp. nov.

( Figs. 22A–F , 26G–H )

Diagnosis. Female. Apical seta longer than maximum width of palpus; tarsomere 5 shorter 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 a narrow transverse strip in middle but each lateral quarter bears 2 long and 2 short setulae at rear margin; sternite VI reduced to a narrow anterior strip and two subsequent small pieces, each bearing 2 long setulae; dorsum of oviscape with about 5–6 minute setulae each side; venter of oviscape with 4 minute setulae.

Female. Body length 1.40–1.42 mm. Frons ( Fig. 22A ) brown, with 18–20 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 slightly concave, 4 setae are about equally distanced. Flagellomere 1 brown and subglobose. Palpus pale brown, with 4 long setae, apical one longer than maximum width of palpus. Labrum and labella yellow.

Thorax brown. Scutellum with two pairs of setae, posterior twice length of anterior. Legs brown, foreleg being lighter. Ratios of lengths of fore tarsomeres about 1.03: 0.74: 0.64: 0.64: 1, with all five bearing a postero-dorsal setal palisade ( Fig. 22C ). Setal palisade terminates 2/3 along mid tibia ( Fig. 22D ). Setae below basal half of hind femur a little shorter than those of anteroventral row of outer half, but about as strong ( Fig. 22E ). Wing ( Fig. 22B ) length 1.15 mm, width 0.59, width/length 0.52 mm. Costal index 0.39–0.42. Costal ratios 1.71–1.72: 1. Costal cilia 0.055–0.058 mm long. Costa with 14–15 dorsal setulae. Alula with 3 setae. Veins brown, membrane brownish gray. Haltere brown.

Abdominal tergites brown and tergites I–V with sparse minute setulae on posterior margins. Tergite VI ( Fig. 26G ) reduced to a narrow anterior strip in middle but each lateral quarter bears 2 long and 2 short setulae at rear margin. Venter brown. Sternite VI ( Figs. 26H ) reduced to a narrow anterior strip and two subsequent small pieces, each bearing 2 long setulae. Oviscape brown. The dorsum of the oviscape with about 5–6 minute setulae each side. The venter of the oviscape with 4 minute setulae ( Fig. 22F ).

Male. Unknown.

Distribution. China (Zhejiang).

Etymology. The species epithet refers to the type locality.

Specimens examined. Holotype. ♀, Zhejiang, Hangzhou, Mt. Tianmu (30°23′48.20″N, 119°26′49.66″E; 940m), 2-July-2013, Lixin Su . Paratypes. 3♀, same data as for holotype ; 2♀, Zhejiang, Hangzhou, Mt. Tianmu (30°20′49.56″N, 119°25′45.23″E; 1000m), 2-July-2013, Lixin Su .

Remarks. The new species seems a little similar to P. parviflavus sp. nov. It differs from the latter by shorter setal palisade of mid tibia, longer setulae of sternite VI and brownish body colour.

Figures

FIGURES 22A–F. Pseudacteon tianmuensis sp. nov., female.A. head, anterior view; B. wing, dorsal view; C. fore tarsus, posterior view; D. mid tibia, posterior view; E. hind femur, anterior view; F. ovipositor, ventral view. Scale bar = 0.1mm.

FIGURES 26A–J. Tergite VI and sternite VI of females.A–B. P. yunnanensis sp. nov.; C–D. P. calceoliformis sp. nov.; E–F. P. hexasetalis Liu et Wang; G–H. P. tianmuensis sp. nov.; I–J. P. parviflavus sp. nov. Scale bar = 0.1mm.