Taxonomic study of the genus Microplitis Förster, 1862 (Hymenoptera, Braconidae, Microgastrinae) from Iran

The genus Microplitis Förster, 1862 (Hymenoptera, Braconidae, Microgastrinae) was studied from northern Iran. Specimens were collected using Malaise traps during 2010–2011. A total of 13 species were collected and identified, of which six species are recorded for the first time from Iran: M. cebes Nixon, 1970, M. docilis Nixon, 1970, M. eremitus Reinhard, 1880, M. kaszabi Papp, 1980, M. pallidipennis Tobias, 1964 and M. varipes (Ruthe, 1860). Two species M. kaszabi and M. pallidipennis are new records for the west Palaearctic region. A new species, Microplitis alborziensis Abdoli & Talebi sp. nov., is described and illustrated. The number of species of Microplitis in Iran is now raised from 17 to 24. A faunistic list, an identification key to all known Iranian species and brief diagnoses and illustrations for all species that have been collected in this study are provided. The validity of the new species is supported by DNA barcoding.


Introduction
Microgastrinae Förster, 1862 is a large and diverse subfamily in the Braconidae with about 3000 described species worldwide (Fernandez-Triana et al. 2020). This subfamily is one of the most important groups of parasitoids in terms of both species richness and economic importance (Rodriguez et al. 2013). Until 1862, all described species in Microgastrinae were assigned to the genus Microgaster Latreille, 1804. Förster (1862) erected two additional genera for Microgastrinae: Microplitis and Apanteles (Whitfi eld et al. 2002).
The genus Microplitis Förster, 1862 comprises 192 described species worldwide including 108 species in the Palaearctic region (Fernandez-Triana et al. 2020). Species of Microplitis are benefi cial parasitoid wasps, predominantly attacking exposed Macrolepidoptera and many of their hosts live fully exposed on vegetation throughout their larval stages. Larvae of species of Microplitis are essentially hemolymph and fat-body feeders, and in many cases their hosts remain alive for several days after the parasitoid larvae exit the host body, which usually takes place from the central or posterior abdominal segments of the caterpillar (Shaw & Huddleston 1991).

Material and methods
Specimens for the present study were collected using Malaise traps from March to November of 2010 and 2011 in northern Iran (i.e., Alborz, Guilan, Mazandaran, Qazvin and Tehran Provinces) (Fig. 1). Malaise traps were placed in a range of diff erent habitats such as forests, rangelands and orchards. The specimens were identifi ed using the keys of Telenga (1955), Papp (1984), Tobias (1986) and Kotenko (2007). Morphological terminology follows Karlsson & Ronquist (2012) for various body parts and Wharton et al. (1997) for wing venation. The specimens were photographed with a Keyence VHX-1000 Digital microscope, using a lens with a range of 13-130 ×. Multiple images through the focal plane were taken of a structure, and latter, these were combined to produce a single in-focus image. The software associated with the Keyence system produced the focused images taken with that camera. The measurements were done using an Olympus™ SZX9 stereo microscope equipped with a graticule. The specimens are deposited at the TMUC.
DNA barcoding of new species focused on the sequencing of a short, standardized portion of the mitochondrial cytochrome c oxidase I gene (COI). The sample in this study (a paratype) had some legs removed for DNA. DNA extraction method follows Brewster & Paoli (2013). The COI gene was amplifi ed using primers (LCO1490-HC02198) following standard protocols (Folmer et al. 1994). The barcode data is stored in the National Center for Biotechnology Information. A map with the Iranian provinces where the species of Microplitis were collected in this study was generated using Simple Mapper (Shorthouse 2010

Diagnosis
Members of this genus are distinguished by having anteromesoscutum densely sculptured, seldom shining, often with notauli which sometimes are strongly defi ned; propodeum evenly curved in profi le, completely rugose and often with a median longitudinal carina but never with any indication of areola; fore wing always with a closed areolet; vannal lobe of the hind wing convex and setose; metacoxa small, not reaching past the posterior margin of T1; metatibial spurs shorter than one-half of metabasitarsus; mesotibial spurs shorter than mesobasitarsus; T1 of variable shape, from widening to narrowing posteriorly and usually sculptured; T2+ smooth, rarely weakly sculptured and often with a weakly delimited trapezoidal median area; T3 always longer than T2, the transverse groove separating them frequently not, or only poorly, defi ned; hypopygium usually rather small but sometimes elongated medially, rarely conspicuously so, occasionally truncate or medially emarginated; ovipositor and its sheath usually short (Mason 1981).

Diagnosis
Antenna shorter than body; head in dorsal view more transverse (i.e., its width / length ratio 1.90) and rounded behind eyes; scutoscutellar sulcus distinctly widened, with eight distinct costulae; length of vein R1 shorter than length of pterostigma; vein 1CUb 2.0 × as long as vein 1CUa; vein r as long as to slightly longer than vein 2RS; T1 length / width ratio 2.0, parallel-sided (or weakly barrel-shaped), rugose to rugulose; tegula, scape and metasomal tergites black; metafemur yellow.
The available data in NCBI shows that two specimens, Microplitis jft111 (European, Sweden, with accession numbers of NCBI: HM396982.1) and Microplitis jft112 (North American, Alaska, with accession numbers of NCBI: HM397413.1), for which there are DNA barcodes available (all based from specimens in the CNC) diff er by 1.7% base pairs (11 base pairs of diff erence) and 1.6% base pairs (10 base pairs of diff erence), respectively, suggesting that they are diff erent species (see Smith et al. 2013for further details).
The new species runs to M. mediator (Haliday, 1834) in the key of Kotenko (2007) from which it can be separated by: (1) head in dorsal view more transverse (i.e., its width / length ratio 1.90) vs head in dorsal view less transverse (i.e., its width / length ratio 1.60-1.70) in M. mediator, (2) hind legs yellow, metasomal tergites and scape black vs hind legs dark brown, metasomal tergites and scape reddish yellow to red in M. mediator.
This species runs to M. aduncus (Ruthe, 1860) in Papp (1984), however, M. aduncus diff ers from M. alborziensis sp. nov. as follows: in M. alborziensis sp. nov. meso-and metafemora are yellow, vein cu-a in hind wing is slightly curved, and T1 is rugose to rugulose, whereas in M. aduncus meso-and metafemora are dark brown to black, vein cu-a in hind wing is distinctly curved, and T1 is smooth.

Host
Unknown.
Colour: body black; antenna, tegula and legs reddish yellow or yellow exception of dark brown metacoxa, metatibia and a dark spot at apical metafemur; pterostigma dark brown.

Discussion
The present study is the fi rst faunistic overview of the genus Microplitis of Iran, in which we present a key for the identifi cation of all known Iranian species. Our samples were collected from fi ve provinces of northern Iran including Alborz, Qazvin, Guilan, Tehran and Mazandaran. The sampled regions in this study belong to the Irano-Anatolian and Caucasus hotspots, which are expected to have the highest biodiversity in Iran (Kiani et al. 2017). According to previous studies, 17 species of Microplitis had been reported from Iran (Farahani et al. 2016;Samin et al. 2018;Fernandez-Triana et al. 2020  No. and % of specimens per province collection data set was showing a huge variation in the number of specimens per site (ranging from one to 72 specimens). Two hundred six specimens (71.03%) were collected from the northern slopes of the Alborz Mountains. The largest number of specimens was found in Orkom (72 specimens, 24.82%) followed by Ghazichak (57 specimens, 19.66%) in Gilan Province. Eight species were only found on the southern slopes of the Alborz Mountains with low populations ( Table 2). Our fi ndings showed that M. tuberculifer with 36.3% and M. spectabilis with 36.9% of all collected specimens were the most commonly collected species. Microplitis tuberculifer was widely distributed in most locations and seems to be a common species in northern Iran. Of the fi ve provinces sampled in this research, Guilan yielded more than 50% of the total number of collected specimens ( Table 2). The 24 species of Microplitis recorded from Iran represent 22.2% of all recorded species in the Palaearctic region (108 species). The number of species of Microplitis in countries adjacent to Iran is recorded as: 58 species in Russia, 30 species in Turkey, 17 species in Turkmenistan, three species in Afghanistan and four species in Tajikistan (Fernandez-Triana et al. 2020).
The genus Microplitis is a diffi cult group for taxonomic studies because its species are similar and in most of the available keys related to this genus in the Palaearctic region, the species are usually separated by colouration of the body (e.g., Papp 1984;Tobias 1986). Adding DNA barcoding data will improve the accuracy of identifi cations in the future.
Since Iran is a large country with various geographical regions, additional new records and species are expected to be found from the region in future studies, and thus this checklist will need to be periodically updated. Finally, more research on Microplitis is required to identify biological attributes for their potential use in pest control, or to protect and conserve them.