Review of the genus Agria (Diptera, Sarcophagidae) from China

Abstract Agria mihalyii (Rohdendorf and Verves, 1978) is recorded from China for the first time, and both sexes are thoroughly documented using a combination of illustrations, photographs and scanning electron microscopy images. The generic affiliation is corroborated from an expanded definition of genus Agria Robineau-Desvoidy, 1830, and a key to males of the two known species from China is provided. The distribution of coeloconic sensilla on the male pre- and postgonite are shown to possess significant diagnostic and phylogenetic information in this genus.


Introduction
The genus Agria Robineau-Desvoidy is a small genus of the subfamily Paramacronychiinae (Sarcophagidae), occurring in the Holarctic region and comprising eight species worldwide (Pape 1987, 1996, 1998, Fan and Pape 1996. The larvae are parasitoids of last instar larvae and pupae of Lepidoptera, occasionally also attacking sawflies (Roback 1954, Pape 1987, Kuhlmann 1995. Pape (1987Pape ( , 1992Pape ( , 1998) published a series of comprehensive taxonomic studies including this genus, which formed the basis for further research on this genus.
Before the present contribution, only A. affinis (Fallén, 1817) was known from China (Fan and Pape 1996). Chao and Zhang (1988) described Agria xiangchengensis from Xiangcheng, Sichuan, but the species does not possess any of the features usually considered diagnostic for species of Agria, which led Pape (1996) to catalogue it under "Unplaced species-group taxa of Paramacronychiinae", and it was subsequently made the type species of a monotypic genus Mimagria by Verves (2001). While checking a series of Agria specimens from Beijing and Shanxi, we found one additional Chinese species, A. mihalyii (Rohdendorf and Verves, 1978). The primary aims of this article are to review the genus Agria from China; to redescribe the newly recorded species; to provide detailed documentation through illustrations, photographs and scanning electron microscopy images of A. affinis and A. mihalyii; and to refine the scientific definition of the genus. A key to the known species of Agria from China is also provided.

Materials and methods
The specimens examined were collected by sweeping from brushwood in mountainous regions and are deposited in the Museum of Beijing Forestry University, Beijing, China.
Methods for the preparation of terminalia, illustrations, photographs and scanning electron microscopy images follow Zhang et al. (2013).
coeloconic sensilla (2.10 µm in height, 1.68 µm in width at the base and 1.20 µm at the middle, and originating from a cuticular ring inside a shallow depression) distributed on distal half (Figs 8E and 8F); juxta very large and shell-shaped, apically with a pair of slanting processes covering most of the acrophallus in lateral view (Figs 4, 8A and 9A−C); phallic tube broad, with the dorsal part dark; acrophallus very broad basally, the distal part strongly tapering and recurving between the juxta (Figs 4, 9B and 9C); lateral sclerotizations short, with a serrated distal margin (Figs 4 and 9C).

Discussion
Pape (1998) investigated the phylogenetic relationships of the world genera of Paramacronychiinae but his analysis gave very little phylogenetic resolution among the genera. More novel morphological characters should be added; especially the structures of the male paramacronychiine genitalia need a much more detailed comparative study. The scanning electron microscopy was here utilized to achieve more morphological details of the male genitalia of Agria. Two features seem to be particularly valuable in corroborating the monophyly of Agria: (1) the shape of the acrophallus, which from a broad base curves back strongly between the juxta, and (2) the pair of lateral sclerotizations originating just distal to the acrophallus and slanting antero-ventrally partly covering the latter. The present SEM documentation has revealed the presence of coeloconic sensilla on the distal half of the A. mihalyii postgonite (Figs 8E and 8F) and on both pre-and postgonite in A. affinis. This type of sensilla has been proposed to be sensitive to chemo-, thermo-, or hygro-stimulation (Altner et al. 1981, Zacharuk 1985, Blackwell et al. 1992, Cribb 1997, and is usually found on the insect antenna, for example: in Diptera (Sukontason et al. 2004, Wang et al. 2012a, Zhang et al. 2012, Lepidoptera (Hunger andSteinbrecht 1998, Binyameen et al. 2012), Hemiptera (Silva et al. 2010, Wang et al. 2012b, and Hymenoptera (Onagbola and Fadamiro 2008). Only few authors have found sensilla on Diptera terminalia (Hooper et al. 1972, Rossignol and McIver 2005, Ngern-Klun et al. 2007, Chaiwong et al. 2007, and this is the first explicit record of the presence and distribution of coeloconic sensilla on the gonites in the subfamily Paramacronychiinae. These sensilla may aid in copulation (Rossignol andMcIver 2005, Chaiwong et al. 2008), and their distribution may therefore be highly species-specific, as indicated by the marked differences between A. affinis and A. mihalyii. Pape (1992) proposed A. mihalyii to be the sister taxon of the remaining species of Agria, with the latter clade supported by two character states: (1) costal spine reduced, and (2) male lower calypter at least partly brownish. The material examined for our study has led us to reinterpret A. mihalyii as having a reduced costal spine, which leaves this character state as phylogenetically uninformative for species-level relationships within Agria. However, two other character states appear to support a basal split between A. mihalyii and the remaining species of Agria, which all share the following: (a) antero-basal bristle of postgonite reduced; and (b) pregonite with numerous coeloconic sensilla scattered across its surface. The latter character state is documented in Fig. 7E for A. affinis and in Kurahashi (1972, figs 2, 3b, 3f) for A. monachae, A. hikosana and A. shinonagai. The distribution of sensilla and other ultrastructural details of male terminalia in Sarcophagidae obviously is a potentially rich source of phylogenetic data, that still remains to be fully explored.
to two anonymous reviewers for their constructive comments on the manuscript. This study was supported by the Program for New Century Excellent Talents in University (No. NCET-12-0783), National Science Foundation of China (No. 31201741), and the Chinese Postdoctoral Science Foundation (No. 20100470009, No. SFG-201104059).