First records of Miracinae (Hymenoptera: Braconidae) from Borneo with description of two new species

. The braconid subfamily Miracinae is recorded for the ﬁ rst time from Borneo. Two new species are described: Rugosimirax obsolescens sp. nov. and Rugosimirax bimacula sp. nov. based on specimens in the Natural History Museum, UK. The relationships of Miracinae genera are discussed.


Introduction
Miracinae Viereck, 1918 (Hymenoptera: Braconidae) is a small subfamily including only 70 species worldwide (Ranjith et al. 2023), though reported from all geographical regions.They are known to be endoparasitoids of leaf-mining lepidopteran larvae (Maetô 1995;Memmott et al. 1994;Shaw & Huddleston 1991;Whitfi eld & Wagner 1991;Yu et al. 2016).They can be distinguished easily from other braconids by the presence of an inverted Y-shaped structure formed by the fi rst three metasomal terga, distinctive reduced fore wing venation, and antennae with 14 segments (Beyarslan 2009;Farahani et al. 2014).Miracinae were originally included in the subfamily Microgastrinae Förster, 1862, before Mason (1981) recognised a new subfamily for this small but unique group.More species (24) are distributed in the Oriental region compared to other regions, which is mainly due to the recent works by Ranjith et al. (2019Ranjith et al. ( , 2023) ) and Ghramh et al. (2019), and the species are mainly from India.Seven species are from South China (Papp & Zhou 1996;Chen et al. 1997;Wu et al. 2000;Chen et al. 2001), two from Vietnam (Belokobylskij 1993) and one from Indonesia (Maetô & Thornton 1993).Before this study, no species of Miracinae had been reported from Borneo, the largest island in the Australo-Oriental region.
We found two species from Borneo that correspond morphologically to Rugosimirax in terms of the irregular propodeum appearance having a roughly U-shaped areola, and a tuft of setae at the ovipositor tip, though they show some differences when compared with the generic diagnosis in Ranjith et al. (2023).Here, we therefore propose a new concept for Rugosimirax, while providing a discussion on all genera of Miracinae.

Material and methods
Specimens studied are deposited in the Natural History Museum, UK (NHMUK).Descriptions and measurements were made using a stereo microscope (Zeiss® Stemi SV6).Photographs of the wasps were taken and processed using a digital camera Zeiss AxioZoom combined with Helicon software or Hirox HRX-01.The images were further processed using Adobe Photoshop® CS6.Morphological terms for body structures and measurements follow Ranjith et al. (2023) andSlater-Baker et al. (2022).The wing vein terminology follows the modifi ed Comstock-Needham system (van Achterberg 1993).The terminology of the cuticular sculpture follows Harris (1979).

Etymology
The specifi c epithet 'obsolescens' derives from Latin, referring to the obsolete posterior depressions on scutellum.

Male
Similar to female, except body length 1.1 mm, fore wing 1.2 mm, antenna slightly longer, body colour lighter, and scutellar hind depressions more obvious.

Host
Unknown.

Remarks
This species is very small (1 mm) which is known only in a North American miracine species Mirax minuta Ashmead, 1893, but it differs distinctly from the latter in the following: propodeum with distinct oblique carinae and transverse carina (propodeum without striae or rugae in M. minuta); head yellow (head black in M. minuta); and 7 terminal fl agellomeres about 3 × as long as wide (shorter, scarcely 2 × in M. minuta).

Etymology
The specifi c epithet 'bimacula' derives from Latin, referring to two pale maculae on basal and apical pterostigma.
HEAD.Transverse in dorsal view, 1.9 × as wide as long, 1.2 × as wide as mesoscutum.Eyes 2.4 × as long as temple dorsally.Temple smooth, nearly impunctate, except minute hairy punctures and shiny, constricted behind eyes in dorsal view (Fig. 2b).Ocelli small, distance between fore and hind ocellus 1.4 × as long as transverse diameter of a hind ocellus, POL:OD:OOL = 3.4:1.0:1.8,anterior ocellus clearly fl at anteriorly and impunctate at sides.Face (Fig. 2c) polished, except superfi cial small punctures close to the eyes, setose and shiny, convex medially, transverse, 1.4 × as wide as high.Clypeus 2.0 × as wide as medial length.Antenna (Fig. 2d) as long as body length, with scape, pedicel and 1 st , 2 nd , penultimate and ultimate fl agellomeres 1.8, 2.0, 5.1, 4.2, 2.9 and 3.6 × as long as wide, 1 st 1.2 × as long as 2 nd , other fl agellomeres subsequent to 2 nd nearly the same size as 2 nd .

Male
Unknown.

Host
Unknown.

Remarks
This species is peculiar in Rugosimirax for having the hind depressions close to each other, with a carina separating them.R. bimacuila is close to Rugosimirax obsolescens sp.nov.but can be easily differentiated from it by the characters in the key.

Discussion
Species of Miracinae have never been well-classifi ed into genera, despite having only 70 species worldwide.The problem is largely due to the use of different diagnostic criteria for the included species listed in each review (Papp 2013;Ranjith et al. 2019;Ghramh et al. 2019;Slater-Baker et al. 2022).To better distinguish Centistidea from Mirax, we have checked all the descriptions of species and identifi ed specimens including primary types in the NHM collection.We have found that the sculpture on the propodeum, and the degree of development of the notauli could be a practical way to separate these three genera, though they often overlap in other characters (see the genus key below).Miracine exhibit much variation though they are rare in all collections worldwide, showing that there are likely to be many more species undescribed, which corresponds with the DNA-sequencing results of Slater-Bakeret et al. (2022).Clearly, more morphological examination and DNA data collection on a larger scale are necessary to give better insight into the systematics of Miracinae.