Miracinae Viereck, 1918

Liu, Zhen & Polaszek, Andrew, 2024, First records of Miracinae (Hymenoptera: Braconidae) from Borneo with description of two new species, European Journal of Taxonomy 935, pp. 283-292 : 289-290

Key to the genus of Miracinae Viereck, 1918

1. Propodeum mostly smooth, never with longitudinal carinae or rugosities, at most with transverse elements (wrinkles, carinae or short rugae) at the posterior end; notauli largely absent, usually faintly impressed anteriorly; vein 1- R 1 of fore wing absent, at most indistinctly extended as apical part of pterostigma (except M. longicaudis ); scutellar hind depressions distinctly separated ............................................................................................................ Mirax Haliday, 1833

– Propodeum with longitudinal carina or rugosity; notauli more developed, longer and crenulated; vein 1- R 1 of fore wing frequently well developed, rarely extended as the attenuated apical part of pterostigma; scutellar hind depressions close, to distinctly separated ................................................ ........................................................................................................................................................... 2

2. Propodeum without a complete median longitudinal carina, instead with a poorly to well defined areola .......................................................................... Rugosimirax Ranjith & van Achterberg, 2023

– Propodeum with a longitudinal carina or rugosity medially and connected to more or less developed costulae ...................................................................................................... Centistidea Rohwer, 1914

Using the above criteria, we concluded that there are only nine species which actually belong to Mirax sensu stricto, i.e., M. minuta Ashmead, 1893 from the Nearctic region; M. cowellensis Slater-Baker & Fagan-Jeffries, 2022 and M. trianguliceps Slater-Baker & Fagan-Jeffries, 2022 from the Australian region; M. caspiana Farahani, Talebi, van Achterberg & Rakhshani, 2014 , M. reperta Papp, 1984 , M. rufilabris Haliday, 1833 , M. sinopticulae He & Chen, 1997 and M. striaca Beyarslan, 2009 from the Palaearctic region; and M. longicaudis Belokobylskij, 1993 from the Oriental region. Mirax longicaudis is peculiar among all species of Miracinae for its exceptionally large size (3.4 mm, others vary from 1 mm to 2.8 mm), aciculate T 2, and longest ovipositor sheath (1.2 × hind tibia, others are more or less the length of the basitarsus). Here, we provisionally keep it in Mirax because of the lack of more detailed information on this species. Except for the smooth appearance of the propodeum, and reduced notauli, specimens of M. longicaudis mostly shared the characters with other Mirax of an indistinct and not crenulated scutellar sulcus and two relatively small, oblong shaped and distinctly apart hind depressions.

Centistidea exhibits more overlaps with the two other genera, as well as having remarkably high species richness (59 species), especially in the Oriental and Neotropical regions. Many of them were misplaced as Mirax in the past. Except for the propodeum with a longitudinal carina or rugosity medially and connected to more or less developed costulae and relatively well developed notauli, this group varies in features of vein 1- R 1, scutellar sulcus, and scutellar hind depressions which are conservative in the genera Mirax and Rugosimirax (Here, we pay more attention on the feature of propodeum for it is the key and widely used character for higher taxa of the closely related Microgastrinae ).

For the Oriental genus Rugosimirax, Ranjith et al. (2023) included three species, namely, R. expectata Ranjith & Priyadarsanan, 2023 , R. glabrator Ranjith & van Achterberg, 2018 from India and R. fereta (Papp & Chou), 1996 from China. Ranjith et al. (2023) paid much attention to ovipositor sheath with a tuft of setae apically for Rugosimirax , but it is actually shared by many other species of Centistidea (see ovipositor sheath images (Figs. 19, 26) for C. mogrus and C. taiwanicus in Papp & Chou 1996) which will be explained in our subsequent paper reviewing this group. We consider a better genus concept for this group by transferring fereta back to Centistidea which it resembles more (median longitudinal rugosity, and scutellar hind depressions close to each other), and by adding the two new species from Borneo. The species of genus Rugosimirax can now be characterized as follows: propodeum with distinct oblique carinae or rugae at sides and a transverse carina or rugae forming an open U-shaped areola, never with a median complete longitudinal carina or rugosity; ovipositor sheath with a tuft of setae apically; comparatively deep and long notauli on disc of mesosoma; and scutellar sulcus narrow and not crenulated.

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 .