First record of the genus Trispinaria Quicke, 1986 (Hymenoptera, Braconidae, Braconinae) in Vietnam, with descriptions of two new species

Abstract Two new species of the genus Trispinaria Quicke, 1986, from Vietnam, viz. T. seminigra Long, sp. nov. and T. vietnamica Long, sp. nov., are described and fully illustrated. Additionally, this is the first record of the genus Trispinaria in Vietnam. A checklist with distributions of previously described species of the genus Trispinaria is given. Comparative characters of the Vietnamese species are provided and modified key couplets are provided to facilitate their identification.


Introduction
Trispinaria was described by Quicke (1986) from SW Sulawesi, including only the type-species Trispinaria priscicolorus Quicke,1986. Trispinaria is an aberrant and rather uniform genus of the subfamily Braconinae. Trispinaria species occur over the Oriental and Australasian regions; van Achterberg (1991) listed and keyed the eight species. Subsequently, Wang et al. (2003) described one new species from China, resulting in eight species described from the Oriental region. A ninth species is recorded from the Australasian region. Quicke (1988) placed Trispinaria as sister group of Physaraia Shenefelt, 1978, because of the fused first and second metasomal tergites and propodeal sculpture. However, van Achterberg (1991) reported that more likely the genus is closely related to the Oriental genus Pseudospinaria Enderlein, 1920. Van Achterberg based his conclusion on the following suit of characters: long and curved vein 1r-m of the hind wing; protruding median carina of metanotum; united dorsal carinae of the first tergite; pair of converging grooves of the second tergite, the third-fifth metasomal tergites possess spines; the first subdiscal cell of the fore wing is more slender; the second tergite has a pair of converging grooves; and the propleuron is concave ventrally. Pseudospinaria differs from Trispinaria by having both basal segments of the metasoma movably jointed, a large fore wing second submarginal cell, bifurcate tarsal claws, and reduced scutellar sulcus. A detailed diagnosis of the genus Trispinaria was given by van Achterberg (1991).
The biology of Trispinaria is unknown but based on the united and heavily sclerotised basal metasomal tergites, van Achterberg (1991) suggested the ovipositor could insert into a hard substrate. Following the points of van Achterberg (1991), the colouration of the wasps corroborates the idea that they occur in open, sunny, and dry types of forest. In tropical rain forests most of the large braconid wasps possess a dark reddish brown and black colour pattern.

Materials and methods
The specimens studied, including holotypes and some paratypes, are housed in the Institute of Ecology & Biological Resources (IEBR) at Ha Noi; other paratypes have been donated to and are deposited in the American Museum of Natural History (AMNH), New York, USA, and the Vietnam National Museum of Nature (VNMN), Ha Noi, Vietnam.

Morphology
For terminology used in this paper, see van Achterberg (1993), sculpture terms are based on Harris (1979), and vein terminology follows the modified Comstock-Needham system (van Achterberg 1993). For a key to the Old World genera of the subfamily Braconinae, see Quicke (1987).
We used an Olympus SZ61 binocular microscope together with fluorescent lamps for sorting, identification and descriptions. The key to species and the descriptions of species are based on females. Measurements are taken under an Olympus SZ40 binocular microscope. The scale-lines of the plates (habitus and fore wing) represent 1.0 mm. The photographs were made with a Sony 5000 digital camera attached to a Nikon SMZ 800N binocular microscope connected to a PC at IEBR and processed with Adobe Photoshop CS5 to adjust the size and background. A distribution map of two new species of Trispinaria was made using Paraview (https://paraview.org).
Abbreviations used in this paper are as follows: In Vietnam, the distribution of the species is given in order of areas and provinces from north to south, and outside Vietnam, distribution of species follows an alphabetical order. Description. Holotype, female, body length 6.2 mm, fore wing length 5.7 mm, antenna 7.3 mm, ovipositor sheath 1.5 mm (Fig. 1).
Male. Unknown. Biology. Unknown. Etymology. From semi (Latin for half ) and niger (Latin for black), because the mesopleuron is black dorsally in contrast to the yellow ventral half.
The new species, T. seminigra sp. nov., is close to T. sannio (Enderlein), from Indonesia and Singapore by sharing the following characters: vein 1r-m of hind wing nearly united with vein 1-SC+R; apical half of subbasal cell of fore wing largely glabrous; and frons smooth. The new species can be inserted into the key by van Achterberg (1991) as follows: 7a.
Male. Unknown. Biology. Unknown. Etymology. The name of the species originates from the name of the country, where the holotype was collected.
The new species, T. vietnamica sp. nov., is similar to T. maculata van Achterberg, from India, Singapore, Sri Lanka, and Taiwan by sharing the following characters: vein 1r-m of hind wing nearly united with vein 1-SC+R; apical half of subbasal cell of fore wing largely glabrous; and frons smooth. The new species can be inserted into the key by van Achterberg (1991) as follows: 7b.
Surroundings of stemmaticum of female yellowish brown; antenna near its apical 0.4 brown; face transversely rugose; fore wing vein r distinctly longer vein 3-SR (cf. fig. 42  Surroundings of stemmaticum of female brownish yellow (Fig. 15); antenna dark brown basally and apically, near its apical 0.4 yellow; face punctatecoriaceous, except triangular area upper clypeus smooth; fore wing vein r as long as vein 3-SR (Fig. 18); vein cu-a of fore wing more or less inclivous than vein 3-CU1 (Fig. 18)

Discussion
The limitations in our paper are that the type specimens of nine species described by van Achterberg (1991) and one species by Wang et al. (2003) could not be examined. However, checking the original descriptions of all the known species revealed that two new species from Vietnam could be distinguished from the other Trispinaria species by their bicoloured antennae, except for two paratype specimens of T. vietnamica sp. nov. which have their antennae dark brown entirely. Comparisons of Trispinaria species from Vietnam show that they are distinguishable from two similar species from the Oriental region, i.e., T. seminigra sp. nov. vs. T. sannio (Enderlein, 1920) from Indonesia and Singapore; and T. vietnamica sp. nov. vs. T. maculata van Achterberg, 1991 from India, Singapore, Sri Lanka, and Taiwan. The colour patterns of wasps seem to be one of the characters for distinguishing between Trispinaria species, including the two new ones from Vietnam. Apart from the bicoloured antennae, most specimens of T. seminigra sp. nov. that possess a black mesopleuron dorsally and metanotum were collected by using sweep nets in the forest understorey and by the Malaise traps set under the canopy forest in the northern and north central parts of Vietnam (Fig. 25). On the contrary, all the specimens of T. vietnamica sp. nov. were widely collected in the more open habitats, i.e., by Malaise trap(s) set in fruit orchards and by using sweep nets above bushes. The colour differences of the two new species discovered from Vietnam support van Achterberg's argument, that in the tropical rain forests most of the large braconid wasps possess a dark(er) colour pattern than those from outside the forest (van Achterberg 1991).