Further addition to the braconid fauna of Iran (Hymenoptera: Braconidae)

Background: The cosmopolitan family Braconidae is one of the largest in the order Hymenoptera. Many of its members are important as biological control agents against more than 120 pest species belonging it four insect orders (Coleoptera, Diptera, Hemiptera, Lepidoptera) that cause economic damage to various agricultural, horticultural, and forestry plants and trees. Due to the lack of regional studies, as well as taxonomic complexities compared with well-studied other western Palaearctic countries, the faunistic knowledge of this family is still largely incomplete. Results: Based on specimens collected from different localities in Iran, as well as material deposited in different Iranian collections, twenty-five braconid species are recorded for the first time from Iran. Collectively, these belong to ten subfamilies (Alysiinae, Brachistinae, Braconinae, Cheloninae, Euphorinae, Exothecinae, Hormiinae, Ichneutinae, Microgastrinae, and Rogadinae). Two genera, Pentatermus Hedqvist (Rogadinae) and Stenobracon Szépligeti (Braconinae), are reported in the present study for the first time. Specimens are identified with the help of specialists, as well as using the available keys for each subfamily. A faunistic list comprising the valid species names and the extralimital distribution are given. Conclusions: In the present study, a list of 25 species and two genera, Pentatermus Hedqvist (Rogadinae) and Stenobracon Szépligeti (Braconinae), are newly recorded from Iran, thus raising the total number of this important group as biocontrol agents to reach 1038 species.


Background
The Braconidae (Hymenoptera: Ichneumonoidea) is one of the most species-rich families in the order Hymenoptera (Quicke and van Achterberg 1990;Wharton 1993;Quicke 2015; Chen and van Achterberg 2019), represented by more than 21,220 described species in more than 1100 genera ). The family is often encountered and almost cosmopolitan (Chen and van Achterberg 2019). Individuals are often black-brown, with reddish markings, though some exhibit striking color and patterns. Braconids are mostly recognized by the following combination of features: vein 2m-cu of fore wing is absent (except in extremely few cases); vein 1RS+M of fore wing is present in almost all members; vein 1r-m of hind wing is present basal to the separation of R1 and RS; and second metasomal tergite is fused with third tergite (secondarily flexible in Aphidiinae) (Sharkey 1993). Many members of the Braconidae have been used as biological control agents against more than 120 pest species belonging it four insect orders (Coleoptera, Diptera, Hemiptera, Lepidoptera) that cause economic damage to various agricultural, horticultural, and forestry plants and trees (Wharton 1993;Austin and Dowton 2000).
Over 40 braconid subfamilies and 114 tribes are currently recognized in the family Braconidae (Chen and van Achterberg 2019). Monophyly of Braconidae is strongly supported in numerous molecular studies (examples are those by van Achterberg 1984;Quicke and van Achterberg 1990;Sharanowski et al. 2011;Li et al. 2016;Quicke et al. 2020).
Faunistic knowledge of the family Braconidae in Iran is largely incomplete due to the paucity of regional studies and, to an extent, greater taxonomic complexity compared with well-studied other western Palearctic countries. Despite these, the Iranian braconid fauna has started to be better investigated, especially over the past 20 years (e.g., Barahoei et al. 2014;Farahani et al. 2016;Beyarslan et al. 2017;Samin et al. 2018a, b;Gadallah et al. 2019). However, Iran is a large country comprising various agro-ecosystems, and therefore, new species are likely to be discovered in future. More than eight hundred species spread over the 30 subfamilies of Braconidae are recognized in Iran to date (Samin et al. 2018a, b;Yu et al. 2016).
Therefore, the aim of the present study is to increase our knowledge about this large and important group of parasitic wasps in Iran.
Here, we record two genera, Pentatermus Hedqvist, 1963 (Rogadinae), and Stenobracon Szépligeti, 1901 (Braconinae), and 25 species for the first time for the Iranian fauna as a part of ongoing faunistic studies.

Methods
The material was mainly collected using Malaise traps or by sweep netting from different regions of Iran. Some additional braconid material deposited in different insect collections (some branches of Islamic Azad University) has also been studied. Here, we follow the classification of Yu et al. (2016) and Chen and van Achterberg (2019). Identifications or confirmations of specimens were done with the help of the late J. Papp (Hungarian Natural History Museum: HNHM) and M. Fischer (Naturhistorisches Museum, Wien, Austria: NMW). Resources used to identify the specimens to the subfamily level included van Achterberg (1993), in addition to the available literature and keys, such as Nixon (1945); van Achterberg (1983,1990,1991); Quicke (1987);Fischer (1993); Tobias et al. (1995); Belokobylskij (1996Belokobylskij ( , 1998Belokobylskij ( , 2002; Chishti and Quicke (1996) The names of the valid species are listed alphabetically within subfamilies, tribes, and genera, respectively. The extralimital distribution listed for each species newly recorded from Iran is based mainly on Yu et al. (2016)

Discussion
Our findings revealed that 25 species are new Iranian records which are distributed across 14 provinces, most in northern areas (Fig. 1) Samin et al. 2018b, in addition to other eight studies with new records after that: Gadallah et al. 2018Samin et al. 2019aSamin et al. , b, 2020  25 new records dealt with in the present study, raise the total number of Iranian Braconidae to reach 1038 species. Among the 30 subfamilies that have been recorded from Iran to date, the Braconinae is the most diverse with 166 recorded species (Fig. 2). Comparison of the Iranian fauna to those of the adjacent countries indicates that Braconidae of Iran has the highest diversity after Russia (with 3207 species) and Turkey (with 1135 species) (Fig. 3); however, these results are biased towards the more sampled regions in some countries and less or without any sampling in some others. Since Iran is a large country with variable ecosystems, more faunistic surveys in different regions will result to new findings (new species, new country records, new distributional data, and parasitoid-host relationships).
Although the Iranian fauna of Braconidae has been studied rather well and cataloged by several authors (see above references), however, the reported species were collected by Malaise traps or sweep netting, so the hosts of most Iranian braconids remain unknown. In this investigation, parasitoid-host relationships have been determined for only seven species (Phanerotoma dentata (Cheloninae), Chremylus elaphus (Hormiinae), Cotesia acuminata, Cotesia melitaearum, Cotesia pieridis, Dolichogenidea imperator, and Iconella lacteoides (Microgastrinae) (28% of the total number of species reported herein) and all the newly recorded hosts belong to the Lepidoptera (families Erebidae, Lasiocampidae, Nymphalidae, Plutellidae, Pyralidae, and Tortricidae). Host determination for the parasitoids is the first step in classical and applied biological control programs (DeBach and Rosen 1991; Bellows et al. 1999).

Conclusion
In the present study, a list of 25 species belonging to ten subfamilies (Alysiinae, Brachistinae, Braconinae, Cheloninae, Euphorinae, Exothecinae, Hormiinae, Ichneutinae, Microgastrinae, and Rogadinae), as well as two genera, Pentatermus Hedqvist, 1963 (Rogadinae), and Stenobracon Szépligeti, 1901 (Braconinae), are newly recorded from Iran. The study is based on specimens collected from different localities in Iran, in addition to material deposited in Iranian collections. A faunistic list comprising the valid species names arranged alphabetically within genera, tribes, and subfamilies is provided, as well as extralimital distribution of species.