Two new species of the genus Microplitis Förster, 1862 (Hymenoptera, Braconidae, Microgastrinae) from China

Abstract Two new species of Microplitis Förster, 1862, M.bomiensis Zhang, sp. nov., and M.paizhensis Zhang, sp. nov. from Tibet, China are described and illustrated. A key to the species of the genus Microplitis Förster from China is added.

In 1982, van Achterberg examined three male specimens of Ichneumon deprimator, and found that the genus Microplitis should not be Microgaster, but rather Microplitis (van Achterberg 1982). Mason (1981) and Whitfield (1987) suggested and recommended to the International Committee of Zoological Nomenclature (ICZN) to abandon Ichneumon deprimator as the type species of Microgaster, and reassigned Microgaster australis Thomson, 1895 as type species of this genus; the original genus names of Diagnosis. Hypopygium usually small, never bearing longitudinal creases along median line. Ovipositor and sheaths usually projecting only a little beyond apex of hypopygium; sheaths bearing a few setae distally. T1 variable from wide to narrow apically and usually moderately sculptured; T2 rarely weakly sculptured and often with a weakly delimited trapezoidal median area; T3 longer than T2, the transverse groove between them poor; remaining tergites nearly smooth. Propodeum usually convexly rounded and often with a distinct percurrent medial keel, never with an areola, surface almost completely rugose, sometimes reticulo-rugose. Mesoscutum often densely sculptured, sometimes smooth, and with notauli, sometimes strongly defined. Posterior band of scutellum usually smooth but interrupted medially by rugosity. Fore wing usually with a D-shaped areolet, shape variable in some species, subtriangular, rectangular, etc.; 1CU1 much shorter than 2CU1; r short. Hind wing with vannal lobe convex and fringed throughout. Hind coxa small and not longer than T1; hind spurs shorter than half length of basitarsus. Labial palpi 3-jointed, sometimes 4-jointed.
Generally, the genus are clearly distinct from other genera. A detailed description of the genus and references to the revised generic diagnosis and Oriental Microplitis species can be made using the most recent data (Mason 1981;Austin and Dangerfield 1993;Ranjith et al. 2015). Comparative diagnosis. This species is similar to Microplitis fujianica Song and Zhang, but can be distinguished by its shiny pronotum, which is sparsely punctate (vs rugose-punctate); fore wing with vein 1R-1 (metacarpus) 1.3× as long as its distance from apex of marginal cell (vs vein 1-R1 1.7× as long as its distance from apex of marginal cell); T2 subrectangular, ratio of apical width: central length = 3.2: 0.7 (vs T2 nearly triangular, ratio of apical width: central length = 3.6: 1.4).
This species is also similar to Microplitis bomiensis, sp. nov. (see below for further diagnosis).
Description. Female (holotype). Head. Roughly triangular in anterior view, with antennal sockets high above the middle level of the eyes. Face slightly convex, finely micropunctate associated with long setae. Inner margin of the eyes straight to moderately emarginate near antennal sockets. Transverse in dorsal view, 1.7× as wide as long, posterior vertex and temples finely punctate to rugose-punctate, with long sparse setae. Mesosoma. Mesosoma almost as wide as head. Pronotum shiny, sparsely punctate. Mesoscutum evenly and densely punctate, setose. Notauli shallow. Scutellar lunules deep, broad, divided by five carinae. Disc of scutellum shiny, weakly convex, evenly punctate, with white setae, its rugose-punctate spot in the middle interrupting the posterior, polished band of scutellum. Propodeum rather evenly curved, coarsely reticulate-rugose, with a median longitudinal carina.
Legs. Hind coxa small, slightly shorter than T1. Inner hind tibial spur almost as long as outer one, about 0.3× as long as hind basitarsus.
Body length 3.2 mm; fore wing length 3.8 mm.

Microplitis bomiensis
Comparative diagnosis. Morphologically this species and M. paizhensis Zhang, sp. nov. are very similar; the main points of distinction are to be found in the former having golden setae on mesoscutum and disc of scutellum (vs light grey or colourless setae on mesoscutum and disc of scutellum). Fore vein 1-R1 1.6× as long as its distance from apex of marginal cell and 1.3× as long as stigma (vs. vein 1-R1 1.3× as long as its distance from apex of marginal cell and 1.1× as long as stigma). Mid coxa reddish brown, hind coxa black brown or infuscate (vs all coxae black).
The new species is also similar to M. helicoverpae Xu & He with the distinction between them as following: vein 1-R1 1.6× as long as its distance from apex of marginal cell and 1.3× as long as stigma (vs vein 1-R1 1.1× as long as its distance from apex of marginal cell and 0.7× as long as stigma). Areolet approximately quadrangular (vs areolet approximately triangular). T1 2.2× as long as wide (vs T1 1.7× as long as wide).
Color. Body generally black to dark brown. Palps yellow to white. Setae of mesoscutum and disc of scutellum golden. Lateral edges of T1-T3 reddish yellow. Hypopygium reddish brown. Antennae dark brown or brown. Wings hyaline, venation brown, stigma with pale yellowish patch basally. Legs yellow, except mid coxa which are reddish brown; hind coxa, tibia, and tarsus black brown or infuscate.
Habitat. Prairie and bushes.

Remarks
Both new species were collected in high-altitude areas in Tibet, China (above 3400 m), which is relatively rare for this group above this altitude. We also collected single male specimen of a third species, which, considering the importance of the females in microgastrine taxonomy and the recommendation of the reviewers, will not be published for the time being.