Encarsia dongbeiana Li & Geng, 2017

Geng, Hui & Li, Cheng-De, 2017, Three new species of the Encarsia inaron (Hymenoptera: Aphelinidae) species group from China with a key to Chinese species, Zootaxa 4306 (2), pp. 208-222 : 210-211

Encarsia dongbeiana Li & Geng , sp. nov.

Figs 2–17

Type material. Holotype. ♀ [on slide, NEFU]: CHINA, Liaoning Province, Anshan City, Qianshan Mountains, Xianrentai , 20.IX.2015, Hui Geng , Xin-Yu Zhang , Ye Chen , sweeping.

Paratypes. 1♀, 1♂ [on slides, NEFU], same data as holotype ; 4♀, 4♂ [on slides, NEFU], CHINA, Heilongjiang Province, Mudanjiang City, Heixiazigou, 26.VIII.2015, Hui Geng , Yan Gao , Zhi-Guang Wu , sweeping ; 1♀, 2♂ [on slides, NEFU], CHINA, Jilin Province, Wangqing County, Daxingou Town, Longshui Village , 24.VIII.2015, Hui Geng , Yan Gao , Zhi-Guang Wu , sweeping.

Diagnosis. Female. Length, mesosoma plus metasoma, 0.57–0.71 mm. Head mainly yellow with postocellar bars dark brown and two short oblique bands above occipital foramen brown ( Figs 2, 3 ). Mesosoma and metasoma entirely dark yellow with only pronotum pale brown. Mid lobe of mesoscutum with 8 or 9 setae; placoid sensilla on scutellum moderately separated ( Fig. 7 ). Fore wing ( Fig. 5 ) 2.52–2.74× as long as wide, marginal fringe 0.26–0.3× as long as wing width. Mid tibial spur 0.54–0.62× as long as corresponding basitarsus ( Fig. 8 ). Ovipositor slightly exerted, about as long as mid tibia; third valvula 0.40–0.46× as long as second valvifer ( Fig. 9 ).

Male. Mostly brown with some paler parts. Antenna with last two flagellomeres partly fused ( Fig. 12 ). Genitalia 0.75–0.84× as long as mid tibia.

Description. Female. Holotype. Length, mesosoma plus metasoma, 0.61 mm. Head yellow except postocellar bars dark brown and two short oblique bands above occipital foramen brown. Antenna ( Fig. 4 ) dark yellow with radicle and scape pale yellow and distal flagellomere brown. Mesosoma and metasoma entirely dark yellow with only pronotum pale brown. Wings ( Figs 5, 6 ) including venation hyaline. Legs completely yellow.

Head (cf. Fig. 2 ), as wide as mesosoma in dorsal view. Ocelli forming about an obtuse triangle, POL<OOL. Stemmaticum (cf. Fig. 3 ) with transversely rugose sculpture. Mandible with two teeth and a truncation (cf. Fig. 2 ). Radicle (R), scape (S), pedicel (P), and 6 flagellomeres with the following ratios of length to width: R: 2.91, S: 3.59, P: 1.55, F1: 1.78, F2: 2.1, F3: 2.2, F4: 1.96, F5: 1.74 and F6: 1.83; relative lengths of R–F6 to length of F1: R: 1.00, S: 2.63, P: 0.88, F1: 1.00, F2: 1.25, F3: 1.38, F4: 1.38, F5: 1.25, and F6: 1.31; flagellomeres with the following numbers of longitudinal sensilla: F1: 1, F2: 2, F3: 2, F4: 3, F5: 3, F6: 3.

Mesosoma 0.68× as long as metasoma. Mid lobe of mesoscutum ( Fig. 7 ) with 9 setae, each side lobe of mesoscutum with 3 setae. Distance between placoid sensilla on scutellum approximately 4.4× maximum width of a sensillum. Distance between anterior pair of scutellar setae 1.64× distance between posterior pair. Fore wing ( Fig. 5 ) 2.59× as long as wide, costal cell with 10 short setae, basal cell with 6 setae, marginal vein with 6 setae along anterior margin; marginal fringe 0.27 × as long as wing width. Mid tibial spur 0.58× as long as corresponding basitarsus, the latter 0.38× as long as mid tibia. Hind tibia 1.04× as long as mid tibia ( Fig.8 ).

Metasoma ( Fig. 9 ) with petiole ( Fig. 10 ) sculptured. T2–T7 with 1+1, 1+1, 1+1, 2+2, 1+4+1 (4 between cercal plates) and 4 setae, respectively. Ovipositor ( Fig. 9 ) slightly exerted, apparently originating from base of T3, 1.03× as long as mid tibia, and 0.75× as long as mid tibia and basitarsus combined. Third valvula 0.46× as long as second valvifer.

Male. Essentially similar to female, differing mainly in colour, antennal structure and genitalia. Head ( Fig. 11 ) yellow except malar sulcus infuscate, a stripe at level of occipital foramen brown, and postocellar bars dark brown. Mesosoma ( Fig. 13 ) largely yellow with pronotum, mid lobe of mesoscutum anteriorly and mediolongitudinally, axillae and propodeum brown. Metasoma brown to dark brown with T6 posteriorly and T7 yellow. Antenna ( Fig. 12 ) dark brown with abundant longitudinal sensilla on all flagellomeres, last two flagellomeres partly fused. Genitalia ( Fig. 17 ) 0.75–0.84× as long as mid tibia.

Host. Unknown.

Variation. Length, mesosoma plus metasoma, 0.57–0.71 mm. Antenna dark yellow to yellowish-brown. Mesosoma and metasoma entirely dark yellow with pronotum, cercal plates and ovipositor stylet apically brown or pale brown. F1 0.94–1.14× as long as pedicel, without or with 1 longitudinal sensillum. Fore wing 2.52– 2.74× as long as wide, marginal fringe 0.26–0.3× as long as wing width. Basal cell with 6–10 setae. Marginal vein usually with 6 or 7 (rarely 5 or 8) long setae along anterior margin. Ovipositor 0.99–1.09× as long as mid tibia, and 0.72–0.79× as long as mid tibia and basitarsus combined. Third valvula 0.4–0.46× as long as second valvifer.

Etymology. dongbei = the Chinese word for northeast; and refers to the distribution of the species in the northeastern part of China.

Comments. E. dongbeiana is similar to E. aferi Schmidt & Polaszek in having the head and body mostly yellowish, but differs from the latter in: mesosoma and metasoma with only pronotum brownish (vs with some brownish patches on mesosoma, petiole and faint transverse band on T1); marginal fringe of fore wing 0.26– 0.3× as long as wing width (vs 0.2–0.21×); distance between anterior pair of scutellar setae 1.4–1.64× distance between posterior pair (vs 1×); ovipositor 0.99–1.09× as long as mid tibia (vs 0.85–0.91×); third valvula 0.4– 0.46× as long as second valvifer (vs 0.3–0.33).

Encarsia dongbeiana also resembles those E. melanostoma Polaszek & Hernández with a completely yellow metasoma (colouration variable in melanostoma as noted in original description), but differs from the latter in different antennal formula, 1,1,4,2 (vs 1,1,3,3), presence of internal sculpture in the cells forming reticulation on mesoscutum (vs absent), pale clypeus and malar sulcus (vs dark) and more distantly placed anterior pair of scutellar setae than that between posterior pair, 1.4–1.64× (vs 0.8–1.1×).

Figures

FIGURES 2 – 6. Encarsia dongbeiana, holotype (except Figs. 2, 3) ♀: 2, head, frontal view (paratype); 3, stemmaticum (paratype); 4, antenna; 5, fore wing; 6, hind wing. Scale bars = 50 µm.

FIGURES 7 – 10. Encarsia dongbeiana, holotype (except Fig. 8) ♀: 7, part of mesosoma with internal sculpture enlarged; 8, legs (paratype); 9, metasoma; 10, sculpture on petiole. Scale bars = 50 µm.

FIGURES 11 – 17. Encarsia dongbeiana, paratype ♂: 11, head, frontal view; 12, antenna; 13, mesosoma and petiole; 14, fore wing; 15, hind wing; 16, (a), tibia and tarsus of mid leg, (b), tibia and tarsus of hind leg; 17, genitalia. Scale bars = 50 µm.