Trechnites verticalis Zu and Li, 2016

Zu, Guohao, Li, Chengde, O, Published & V, Final, 2016, Two new species of Trechnites (Hymenoptera: Encyrtidae) from China and a key to Chinese species, Turkish Journal of Zoology 40 (1), pp. 35-39 : 36-39

3.2. Trechnites verticalis Zu and Li , sp. nov. ( Figure 2 )

Type material: Holotype. ♀ (E1304–02), CHINA, Yunnan Province, Longchuan County, 26– 28.04.2013, YPT. 1 ♀, leg. Guo-Hao Zu, Hui-Lin Han, Xiang-Xiang Jin, Chao Zhang ( NEFU).

Description. Female (holotype). Body length 1.16 mm. Body generally dark brown. Frontovertex with blue metallic reflection; eyes dark reddish brown; ocelli dark red; gena and scrobe with purple reflection. Antennae with radicle and basal two-thirds of scape dark brown to black, apical third yellow; pedicel mostly dark brown, with extreme apex yellowish; flagellar segments yellowish brown, except distal two segments of clava paler. Mesoscutum with faint bluish green reflection, scutellum with bright green metallic reflection. Wings hyaline with venation brown. Legs with all coxae, femora except basal fourth of mid femora, about basal half of foretibiae and hind tibiae brown to dark brown, remaining parts of legs white to pale yellow, except last tarsal segments a little darker and a faint brownish tinge on hind trochanters.

Head ( Figure 2G ) in facial view, 1.13× as wide as high, 2.61× as wide as frontovertex. Frontovertex with shallow and regular reticulate sculpture. Ocelli forming a nearly right triangle. Eyes with medial margins slightly diverging ventrally. Antennal scrobes moderately deep, meeting dorsally, inverted U-shaped, sides and dorsal margin rounded, toruli separated from mouth margin by their own widths, their dorsal margins below the level with ventral eye margins. Malar space 0.46× as long as eye length.

Antenna ( Figure 2I ) with radicle about 2.5× as long as wide; scape cylindrical, about 5.92× as long as wide; pedicel about 2.92× as long as wide, much longer than F1–F3 combined; F1 and F4 quadrate, remaining funicular segments slightly wider than long; F2 0.82× as long as wide; F3 0.8× as long as wide; F5 0.83× as long as wide; clava 3-segmented, apex slightly transversely truncate, 2.53× as long as wide and a little longer than F3–F5 combined; funicle with linear sensillae on F4–F5.

Thorax ( Figure 2H ). Mesoscutum 1.57× as wide as long, with notaular lines complete, meeting before posterior margin of mesoscutum. Scutellum 1.24× as wide as long, and almost as long as mesoscutum, apex acute, extending beyond posterior margin of metanotum. Mesoscutum with fine, scale-like, more or less transverse sculpture; scutellum with fine, longitudinally lineolate-reticulate sculpture.

Forewing ( Figure 2J ) 2.27× as long as wide; costal cell 10.83× as long as wide, with 2 complete lines of setae along anterior margin and 2–3 incomplete on about basal third; venation 0.42× as long as forewing; marginal vein punctiform, postmarginal vein virtually absent, stigmal vein long and nearly straight, truncated and enlarged apically, almost vertical to distal part of submarginal vein. Linea calva closed by 1–2 lines of setae posteriorly, uninterrupted, filum spinosum directed to distal part of stigmal vein. Basal cell with a naked area at base. Marginal fringe short, a little longer than the longest setae on basal cell.

Hind wing ( Figure 2K ) relatively wide, 4.24× as long as wide; submarginal vein distinctly down curved. Linea calva absent. Basal cell naked posteriorly and basally, and also beneath the distal part of submarginal vein. Marginal fringe remarkably much longer than the setae on basal cell.

Legs ( Figure 2L ) normal. Apical rim of mid tibia with 6 pegs; mid tibial spur 0.75× as long as corresponding basitarsus.

Gaster ( Figure 2H ) 1.02× as long as thorax. Cercal plates in basal half. Ovipositor slightly exserted, approximately 0.86× as long as mid tibia. Gonostylus free, strongly bent upward; thus the accurate measurements is impossible, presumably about one and a half times as long as wide and about one-third as long as second valvifer.

Relative measurements (length/width): thorax 564; gaster 574; OL 267. MS 122; FV 163, EL 267, POL: 67; OOL: 22; OCL: 22. Antenna: radicle 60/24; scape 185/31; pedicel 91/31; F1 24/24; F2 22/26; F3 24/30; F4 36/36; F5 36/43; clava 125. Forewing 1220/537. Hind wing 713/168.

Male. Unknown.

Host. Unknown

Etymology. Latin: verticalis = vertical; and refers to the stigmal vein of forewing almost vertical to distal part of submarginal vein.

Comparative notes. T. verticalis sp. nov. resembles the following 6 species: T. alni (Palaearctic Region), T. concinnus ( India), T. dubiosus ( Russia), T. merops ( Costa Rica), T. sadkai (Palaearctic Region), and T. secundus (Oriental Region), by having 3-segmented clava, complete notaular lines, and mostly dark colored legs. The new species can be easily separated from all of them, except dubiosus , by sculpture on scutellum, general body color, shape of antennae (especially the apical part of clava), and ovipositor. Furthermore, it differs from T. alni by having forewing hyaline (slightly and uniformly infuscate in T. alni ), gonostylus about 1.5× as long as wide (approximately 6× in T. alni ); from T. concinnus by longer malar space, 0.46× as long as eye length (about 0.3× in T. concinnus ), and wider forewing, 2.27× as long as wide (2.8× in T. concinnus ); from T.merops by pale yellow hind tarsi (brown in T. merops ) and free gonostylus (partially fused to second valvifer in T. merops ); and from T. sadkai and T. secundus by more or less rounded clava (strongly obliquely truncate in T. sadkai and T. secundus ).

T. dubiosus was inadequately described by Sharkov and Trjapitzin in 1995. According to the brief original description in key and figures, the new species differs from T. dubiosus in having linea calva closed (open in T. dubiosus ), funicle with linear sensillae on F4–F5 (on F3–F 5 in T. dubiosus ), F1–F3 distinctly shorter than F4– F5 (not distinct in T. dubiosus ), and stigmal vein almost vertical to distal part of submarginal vein (distinctly in an obtuse angle in T. dubiosus ). The last character is rather outstanding among the species of the genus.

Figures

Figure 2. (G–L) T. verticalis sp. nov. (female): G) Frontal aspect of head, H) Dorsal aspect of thorax and gaster, I) Antenna, J) Forewing, K) Hind wing, L) Legs. Scale bars = 100 μm.