Pseudacteon inticlinatus, 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 : 209

4. Pseudacteon inticlinatus sp. nov.

( Figs. 5A–F , 24E–F )

Diagnosis. Female. Apical seta shorter than maximum width of palpus; fore tarsomere 5 longer than fore tarsomere 1; setal palisade 3/4 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 with 3 long setulae; sternite VI not divided, with 4–5 very long setae each side; dorsum of oviscape with 8 short setulae each side, of which five are short and stout.

Female. Body length 1.04 mm. Frons ( Fig. 5A ) brown, with 36–40 setulae. Supra-antennal setae as strong as adjacent frontal setae, lower pair being closer together and a little higher than lower fronto-orbital setae. Lower interfrontal seta directly under lower fronto-orbital seta. Lower fronto-orbital setae near to eye margin and a little lower on frons than upper supra-antennal setae. Second row of frontal setae a little concave, with upper interfrontal setae clearly further apart than either is from an upper fronto-orbital seta. Flagellomere 1 brown and subglobose. Palpus pale brown, with short setae, apical one as long as adjacent setulae and shorter than maximum width of palpus. Labrum pale brown. Labella pale brown and with long and curved setulae.

Thorax brown. Scutellum with two pairs of setae, posterior twice length of anterior. Legs yellowish brown to brown, hind femora being darkest. Ratios of lengths of fore tarsomeres about 0.84: 0.74: 0.69: 0.65: 1, with all five bearing a setal palisade ( Fig. 5C ). Setal palisade extends more than 3/4 (0.72) length of mid tibia ( Fig. 5D ). Setulae below basal half of hind femur longer than adjacent setulae of anterior face, but clearly shorter and weaker than those of anteroventral row of outer half ( Fig. 5E ). Wing ( Fig. 5B ) length 1.08 mm, width 0.55 mm, width/length 0.51. Costal index 0.40. Costal ratios 1.55: 1. Costal cilia 0.024–0.025 mm long. Costa with 16 dorsal setulae. Alula with 2 setae. Veins brown, thin veins being paler. Membrane brownish gray. Haltere pale yellow.

Abdominal tergites brown and tergites 1–5 with sparse minute setulae only. Tergite VI ( Fig. 24E ) reduced to a narrow anterior strip in middle but each lateral quarter bears 3 long setulae at rear margin. Sternite VI ( Fig. 24F ) with 4–5 long setae each side. Oviscape arched. The dorsum of the oviscape with about 8 short and stout setulae each side, of which five near apex are short and stout ( Fig. 5F ).

Male. Unknown.

Distribution. China (Jilin).

Etymology: The species epithet refers to characters of setae on abdominal sternite VI.

Material examined. Holotype. ♀ (slide), Jilin, Changbai, Ershisandaogou (41°34′44.26″N, 128°31′21.00″E), 29-July-2014, Jianfeng Wang . Paratypes. 1♀, same as for holotype; 1♀, Jilin, Tonghua, Jian (41°16′26.57″N, 126°0 7′03.25″E, 738 m), 22-Jul-2014, Jiangfeng Wang .

Remarks. The new species is similar to P. setipalpatus Disney et Michailovskaya, 2000 , it is distinguished from the latter by apical seta shorter than maximum width of palpus, and abdominal sternite VI with 4–5 inclinate, long setae each side. This species looks also similar to P. trapeziformis Zhang et Liu, 2019 , it differs from the latter in having more frontal setulae, longer setae of palpus and the number and arrangement of setulae on sternite VI.

Figures

FIGURES 5A–F. Pseudacteon inticlinatus 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, dorsal view. Scale bar = 0.1mm.

FIGURES 24A–J. Tergite VI and sternite VI of females.A–B. P. quadrisetalis Liu et Cai; C–D. P. trapeziformis Zhang et Liu; E–F. P. inticlinatus sp. nov.; G–H. P. setipalpatus Disney et Michailovskaya; I–J. P. reticulatus sp. nov. Scale bar = 0.1mm.