A taxonomic study of Ooctonus (Hymenoptera, Mymaridae) from Heilongjiang, China

Abstract Five species of Ooctonus Haliday (Hymenoptera, Mymaridae) from Heilongjiang Province, China, are reviewed. One species, Ooctonus huberi sp. n., is described as new, and four species, Ooctonus orientalis Doutt, Ooctonus saturn Triapitsyn, Ooctonus sublaevis Förster and Ooctonus vulgatus Haliday are reported as new to China. A key to the females of the 10 described Chinese species is given. All the specimens are deposited in the insect collections of Northeast Forestry University, China.


Introduction
Ooctonus currently contains 36 described species: one in the Australian region (Perkins 1905), 12 in the Palaearctic region, five in the Oriental region (Triapitsyn 2010), 14 species in the Nearctic region including three also distributed in the Palaearctic region (Huber 2012), three in the Afrotropical region (Huber et al. 2010), and four in the Neotropical region (Huber 2013). Here we describe a new species, record 4 others for the first time from northeast China, and provide a key to females of the 10 Ooctonus species known from China.

Materials and methods
Twenty-three specimens (19 females and 4 males) of Ooctonus were collected in Heilongjiang Province, northeast China by sweeping, Malaise traps (MT) or yellow pan traps (YPT). Specimens were dissected and mounted in Canada balsam on slides following the method described by Noyes (1982) and modified for Mymaridae by Huber (1988). Photographs were taken with a digital CCD camera attached to an Olympus BX51 compound microscope, and most measurements were made from slide-mounted specimens using an eye-piece reticle. Total body length excluding ovipositor was measured with an eye-piece reticle from alcohol-preserved specimens before being dissected. All measurements are given in micrometers (μm). Triapitsyn (2010) and Huber (2012) should be consulted for depositories of type specimens, hosts, and literature references to species described from Palaearctic, Oriental, and Nearctic regions. Morphological terminology and abbreviations are those of Huber (2012). All the specimens listed below are deposited in Northeast Forestry University, Harbin, China (NEFU).  plica without an anterior bifurcation; petiole 3.54-4.05× as long as wide; ovipositor ( Fig. 7) slightly exserted, about 0.9× as long as gaster, and 0.86-0.90× as long as metatibia.

Key to the females of Ooctonus species in China
Ooctonus huberi sp. n. runs to O. novickyi in Triapitsyn's key (2010), and the differences are shown in the key above. The new species is also similar to O. lokomotiv. Both species have 1 mps sometimes on fl 3 and 2 mps on fl 4 -fl 8 and have reticulation on mesoscutum and frenum, but O. huberi sp. n. differs from the latter by having 7 mps on the clava (8 mps in O. lokomotiv); petiole 3.54-4.05× as long as wide (2.6-3.3× in O. lokomotiv); and ovipositor 0.86-0.90× as long as metatibia (1.2-1.4× in O. lokomotiv).
Description. Female. Body length 1240-1380. Head and mesosoma dark brown, metasoma brown; scape and pedicel mostly yellow except dorsally dark brown; fl 1 brown, remainder of funicle dark brown; petiole and legs yellow except apical tarsomere brown.
Male. Body length 1230-1310. Mid ocellus diameter 29-31. Antenna (Fig. 8) Diagnosis. Funicle (Fig. 12) usually with 2 mps on fl 5 -fl 8 and 7 mps on clava; mesoscutum ( Fig. 13) with median longitudinal groove, the groove sometimes very short at posterior margin of mesoscutum or extending about 0.7× length of mesoscutum; frenum entirely reticulate; propodeum ( Fig. 13) with median areole separated from metascutellum by long median carina; plica bifurcate anteriorly with a long lateral and shorter medial arm. Triapitsyn, 2010Figs 16-24 Triapitsyn 2010. Diagnosis. Funicle (Fig. 16) with 2 mps on fl 7 and fl 8 and 7 mps on clava; mesoscutum ( Fig. 19) with median longitudinal groove, the groove sometimes very short  Diagnosis. Funicle (Fig. 25) usually with 2 mps on fl 5 -fl 8 (occasionally fl 6 with just 1 mps) and 7 mps on clava; mesoscutum (Fig. 27) usually without median longitudinal groove, rarely with a very short groove; frenum with weak reticulate sculpture; propodeum ( Fig. 27) with median areole well separated from metascutellum by fairly long median carina, but the median carina often incomplete, not extending to anterior margin of propodeum, or almost absent; plica straight or slightly curved outward and not divided anterodorsally. except for obscure sculpture at lateral borders and sometimes also at anterior margin; propodeum ( Fig. 34) with median areole abutting metascutellum; the median carina absent and replaced by the two carinae forming inner margin of dorsolateral areoles; plica almost straight and not divided anterodorsally, ending just anterior and medial to stub.