Encarsia yunnana Li & Geng

Geng, Hui & Li, Cheng-De, 2016, Five new species of genus Encarsia Förster from China (Hymenoptera: Aphelinidae), Zootaxa 4162 (3), pp. 535-549 : 546-548

Encarsia yunnana Li & Geng , sp. nov.

Figs 31–38

Type material. Holotype. ♀ [on slide], ( NEFU), CHINA, Yunnan Province, Baoshan City, Tengchong County, Yinghe Village , 1820m, 17–19. VII. 2012, Xiang-Xiang Jin , Hui Geng , Chao Zhang , YPT.

Paratypes. 3♀ [on slides], same data as holotype. ( NEFU).

Diagnosis. Female. Length, mesosoma plus metasoma, 0.5–0.66 mm. Ocelli forming a right to slightly obtuse triangle. POL distinctly less than OOL. Mandible with two teeth and a truncation. Maxillary and labial palpi 1- segmented. Antennal formula 1:1:4:2. Mid lobe of mesoscutum with 2 setae; each side lobe with 2 setae; axilla with 1 seta; distance between placoid sensilla on scutellum approximately 2–4× maximum width of a sensillum; distance between anterior pair of scutellar setae about equal to that between posterior pair. Fore wing 3.21–3.36× as long as wide, with an asetose area around stigmal vein; marginal fringe 0.67–0.8× as long as wing width. Tarsal formula 5:5:5. Mid tibial spur 0.88–0.97× as long as corresponding basitarsus. Petiole with sculpture laterally. T7 2.52–2.6× as wide as long. Ovipositor not or hardly exerted, 0.93–1.1× as long as mid tibia; third valvula 0.36– 0.4× as long as second valvifer.

Description. Female. Holotype. Length, mesosoma plus metasoma, 0.66 mm. Head and body pale yellow except pronotum brown, petiole, T1 and T4–6 with very faint brownish bands. Ovipositor yellow. Antennae pale yellow. Fore wing hyaline, venation pale except stigmal vein mostly and base of submarginal vein slightly infuscate. Hind wing hyaline. Legs pale yellow.

Head ( Fig. 31 ) a little broader than mesosoma. Frontovertex 0.67× as broad as head width. Eyes with fine and transparent setae. Ocelli forming about a right triangle, POL distinctly less than OOL. Stemmaticum with reticulate sculpture. Mandible ( Fig. 31 ) weakly dentate, with two teeth and a truncation. Maxillary and labial palpi 1- segmented. Antennae inserted at level of lower margin of eyes. Antennal formula, 1:1:4:2 ( Fig. 32 ); radicle (R), scape (S), pedicel (P), 4 funicle segments (F1–F4) and 2 club segments (F5–F6) with the following ratios of length to width: R: 2.20, S: 4.13, P:1.44, F1: 1.83, F2: 2.42, F3: 1.88, F4: 1.75, F5: 1.73 and F6: 1.86; relative lengths of segments R–F6 to length of F1: R: 1.00, S: 3.00, P: 1.24, F1: 1.00, F2: 1.32, F3: 1.36, F4: 1.59, F5: 1.64 and F6: 1.90; flagellum with the following numbers of longitudinal sensilla: F1: 0, F2: 1, F3: 1, F4: 3, F5: 3, F6: 3.

Mesosoma (cf. Fig. 33 ) 0.75× as long as metasoma. Mid lobe of mesoscutum and axillae indistinctly reticulate. Mid lobe of mesoscutum with 2 setae near posterior margin, each side lobe with 2 setae. Axilla with 1 seta. Scutellum 2.08× as wide as long, and 0.62× as long as mid lobe. Distance between placoid sensilla on scutellum approximately 4× maximum width of a sensillum. Anterior pair of scutellar setae distinctly shorter and thinner than posterior pair, and distance between anterior pair 0.92× that between posterior pair. Endophragma rounded at apex, extending to anterior margin of T2. Fore wing ( Fig. 34 ) 3.3× as long as wide, with a small asetose area around stigmal vein; costal cell with 4 short setae in basal half; basal cell with 2 setae; submarginal vein with 2 setae; marginal vein 1.26× as long as submarginal vein, with 4 setae along anterior margin; marginal fringe 0.67× as long as wing width. Hind wing ( Fig. 35 ) 7.69× as long as wide, marginal fringe 1.54× as long as wing width. Tarsal formula 5:5:5. Mid tibial spur 0.92× as long as corresponding basitarsus ( Fig. 36 ), and the latter 0.28× as long as mid tibia. Hind tibia as long as mid tibia.

Metasoma ( Fig. 37 ) with petiole ( Fig. 38 ) sculptured laterally. T1–T4 with scale-like reticulation laterally. T2– T7 with 1+1, 1+1, 1+1, 2+2, 1+2+1 and 4 setae, respectively. T7 2.59× as wide as long. Ovipositor not or hardly exerted, apparently originating from anterior margin of T4, 1.05× as long as mid tibia, and 0.83× as long as mid tibia and basitarsus combined. Third valvula 0.37× as long as second valvifer.

Male. Unknown.

Host. Unknown.

Variation. Antennal segment F3 with 1–2 longitudinal sensilla. Distance between placoid sensilla on scutellum approximately 2–4× maximum width of a sensillum. Axillae completely yellow (slightly brownish at apex in one paratype). Marginal vein of fore wing with 4 or 5 (in one paratype with 6–8) setae along anterior margin. In one paratype, 1 seta present at apex of stigmal vein of fore wing.

Etymology. The specific name is derived from the collection locality name.

Comments. This new species is placed in the E. parvella- group as defined by Polaszek & Gill (2011), except for the host being unknown, in having all tarsi 5-segmented, fore wing with an asetose area around the stigmal vein, marginal fringe of the fore wing not longer than the wing width, and each side lobe of the mesoscutum with 2 setae. However, it is easily separated from all the species of the group by the following combination of characters: only 2 setae on the mid lobe of the mesoscutum, relatively densely setose fore wing disc, laterally sculptured petiole, and relatively short third valvula (less than 0.5× second valvifer).

Encarsia yunnana resembles E. gerlingi Viggiani (1989) in similar body color, antennal structure, similar shape, setation, pigmentation on venation of the fore wing, and relatively short third valvulae, but is distinguished from the latter by: mid lobe of mesoscutum with 2 setae (vs 8 setae), marginal fringe of fore wing relatively long, 0.67–0.80× as long as wing width (vs shorter than half of wing width), and distance between anterior pair of scutellar setae about equal to that between posterior pair (vs distinctly shorter).

Figures

FIGURES 31 – 38. Encarsia yunnana sp. nov., holotype (except Fig. 33) ♀: 31, head, frontal view, with mandibles enlarged; 32, antenna; 33, mesosoma (paratype); 34, fore wing; 35, hind wing; 36, mid tibial spur and tarsi; 37, metasoma; 38, sculpture on petiole. Scale bars = 50 µm.