Bull. Natl. Mus. Nat. Sci., Ser. A, 35(4), pp. 249–278, December 22, 2009 The Species-group of Arge captiva (Insecta, Hymenoptera, Argidae) Akihiko Shinohara1, Hideho Hara2 and Jung-Wook Kim3 1 Department of Zoology, National Museum of Nature and Science, 3–23–1 Hyakunin-cho, Shinjuku-ku, Tokyo, 169–0073 Japan E-mail: [email protected] 2Hokkaido Forestry Research Institute, Koshunai, Bibai-shi, Hokkaido, 079–0198 Japan E-mail: [email protected] 3 Public Health Pest Management, DENR, Raleigh NC, USA E-mail: [email protected] Abstract Arge captiva (Smith, 1874) and its allied taxa are revised and four species are recog- nized. All relevant type material was studied, except for that of Arge praesternalis Malaise, 1934. Arge macrops sp. n. (ϭArge sanguinolenta auctt., nec Mocsáry, 1909) is described and illustrated from the Primorskij Kraj, Korea and China. The following synonymy is established or confirmed for Arge captiva: Arge captiva (Smith, 1874) (ϭHylotoma captiva Smith, 1874ϭHylotoma flavi- collis Cameron, 1876 [syn. n.]ϭArge sanguinolenta Mocsáry, 1909 [syn. n.]ϭArge kolthoffi For- sius, 1927 [syn. n.]ϭArge captiva rufoscutellata Takeuchi, 1927). Arge siamana Togashi, 1988, is removed from synonymy with A. captiva. A little known species, A. praesternalis, is treated as a valid species. Key words : Argidae, Arge captiva group, Arge macrops, new species, new synonymy. The sawfly genus Arge (Hymenoptera, Argi- a median carina and the nearly glabrous outer dae) is represented by more than 300 described margins of the wings. The larvae of A. rejecta are species in the world, including about 120 species known to feed on Rubus spp., whereas those recorded from eastern Asia (Gussakovskij, 1935; of A. captiva are associated with Ulmus spp. Takeuchi, 1939; Smith, 1989, 1992; Wei et al., (Okutani, 1967). 2006). Among the eastern Asian representatives A total of nine previously described taxa may of the genus, there are two groups of species belong to the two groups: A. captiva (Smith, whose adults are black or bluish black with red- 1874), A. flavicollis (Cameron, 1876), A. rejecta dish areas on the thorax. The species of the two (Kirby, 1882), A. vulnerata Mocsáry, 1909, A. groups are similar in color pattern but greatly sanguinolenta Mocsáry, 1909, A. kolthoffi For- different in structure. One of the groups, herein sius, 1927, A. captiva rufoscutellata Takeuchi, named the rejecta group, includes A. rejecta 1927, A. praesternalis Malaise, 1934, and A. sia- (Kirby, 1882) and its allies. The members of the mana Togashi, 1988. Arge captiva var. watanabei rejecta group are comparatively small species Takeuchi, 1932, is regarded as an infrasubspecif- characterized by the medially distinctly carinate ic unavailable name (Blank et al., 2009) and thus supraclypeal area on the head and the pilose will not be discussed further in the present paper. outer margins of the wings. The other group, Taxonomy of these species is in need of revision, herein named the captiva group, is represented because recent works differ in the interpretation by A. captiva (Smith, 1874) and its allies, which of these taxa, particularly as to the placement of are comparatively large and robust species distin- A. flavicollis and A. siamana (Wei and Wen, guished from the members of the rejecta group 2000; Wei and Nie, 2003; Saini et al., 2006). Wei by the roundly swollen supraclypeal area without and Wen (2000) synonymized A. flavicollis with 250 Akihiko Shinohara, Hideho Hara and Jung-Wook Kim A. captiva, thus placing the species in the captiva Hokkaido Forestry Research Institute, Bibai; group, whereas Saini et al. (2006) treated them HNHMB – Hungarian Museum of Natural Histo- “as two separate species which are similar in ry, Budapest; HSC – H. Suda collection, Sakura; color but differ in morphology”, thus suggesting HSLC – H.-S. Lee collection, Suwon; HU – the placement of A. flavicollis in the rejecta Hokkaido University, Sapporo; HYC – H. Yoshi- group. Wei and Wen (2000) also placed A. sia- da collection, Kobe; KU – Kobe University, mana in synonymy with A. captiva, but Saini et Kobe; MCZ – Museum of Comparative Zoology, al. (2006) mentioned, “this placement requires Cambridge; MNHAH – Museum of Nature and closer scrutiny”. It should be noted that these Human Activities, Hyogo, Sanda; NRMS – works were not based on the examination of the Swedish Museum of Natural History, Stockholm; type material, and this is doubtless the main NSMT – National Museum of Nature and Sci- source of confusion. ence, Tokyo; OMNH – Osaka Museum of Natural We were able to examine the type material of History, Osaka; OPU – Osaka Prefecture Univer- all the taxa stated above, with the exception of A. sity, Sakai; SDEI – Senckenberg Deutsches Ento- praesternalis. In the following lines, we will re- mologisches Institut, Muncheberg; SNM – Natur- vise the taxa belonging to the captiva group al History Museum of Denmark, Copenhagen; based on the examination of the type material SNU – Seoul National University, Suwon (partly and a series of specimens from various parts of on permanent loan from Kangwon National Uni- eastern Asia. Besides A. rejecta and A. vulnerata, versity, Chuncheon, and Gyeongsang National all the taxa cited above belong to the captiva University, Jinju); USNM – National Museum of group. In conclusion, we have recognized four Natural History, Washington, D.C.; ZSSM – species in the captiva group, namely A. captiva, Bavarian State Collection of Zoology, Munich. A. siamana, A. praesternalis and A. macrops sp. For the scientific names of the host plants, we n. Arge flavicollis, A. sanguinolenta, A. kolthoffi followed Yonekura and Kajita (2009). and A. captiva rufoscutellata are synonymous with A. captiva, which is a widespread species The Arge captiva Group showing large variations in the color pattern of the thorax. The color variations are generally as- The species of the captiva group are character- sociated with geography but not clear-cut enough ized as follows: Rather large and robust species to recognize subspecies in our view. Judging (Fig. 1), length 7–12.5 mm in females and 7–11 from the original description, A. praesternalis mm in males. Black, with bluish or purplish re- may also be a synonym of A. captiva, but we flection; thorax usually with large reddish areas. treat it as a valid species until more information Interantennal carinae (Fig. 2A, E, J) distinct, becomes available. Arge siamana is very similar nearly straight, subparallel or convergent below to A. captiva in external morphology but distin- between level of dorsal margins of antennal sock- guishable from it in the shape of the ovipositor. A ets and level of middle inner orbits, and then be- peculiar species characterized by the exceptional- coming indistinct and strongly convergent ven- ly large eyes and ocelli was previously identified trally on supraclypeal area; supraclypeal area with A. sanguinolenta, but this is a misidentifica- roundly swollen, top surface nearly flattened, tion and the species will be described under the without median carina, but with very shallow, in- name of A. macrops below. conspicuous longitudinal depression or groove The material used in this work is kept in the along median line enclosed by ventral parts of following collections: BMNH – The Natural His- usually inconspicuous V-shaped interantennal tory Museum, London; CAS – California Acade- carinae. Right mandible with inner margin dis- my of Sciences, San Francisco; CSFU – Central tinctly notched. Cell 2Rs in forewing (Fig. 2P–R) South Forestry University, Changsha; HFRI – very broad (apical length [ϭcrossvein 3r–m Arge captiva Species-group 251 length] about 0.6–0.9ϫ posterior width), not or members of the captiva group agree with the di- weakly widened towards apex, with anterior agnosis of the pectoralis group, except that the width about as long as or shorter than posterior gap between the 2nd and 3rd serrulae of the width (0.7–1.0 : 1.0); crossvein 2r–m usually bent lancet is not larger than between others. towards base or sinuate and crossvein 3r–m near- Extremely dark specimens of A. captiva, hav- ly straight or weakly curved outwards; in both ing no reddish areas on the thorax, look similar wings, wing margin between veins Rs and Cu to black or bluish black species with the swollen nearly glabrous, setae not protruding beyond and non-carinate supraclypeal area and the wing margin (Fig. 2S). Sawsheath rather short, glabrous outer margins of the wings, such as A. rounded, with median lobe very small and locat- pullata (Zaddach, 1859) or A. enodis (Linnaeus, ed at base in posterodorsal view (Fig. 2D, H, M), 1767). These two species will be distinguished with large swelling at base in lateral view (Fig. from A. captiva by the roundly swollen supra- 2I). Lance (Fig. 4) with apical crest well devel- clypeal area without very shallow longitudinal oped, roughly serrate and with narrow membra- groove or depression at middle, the narrow and nous areas at middle and with groups of rudi- usually apically widened cell 2Rs in the forewing mental setae at intervals along ventral margin at (ratio of apical length to posterior width is middle. Lancet (Figs. 5–7) in lateral view rather 0.6–0.9 in A. captiva group, whereas it is 0.9–1.4 thick, with rounded apex and about 22–27 serru- in A. pullata, 0.9–1.1 (female) and 0.8–0.9 lae as recognized by number of marginal sensilla; (male) in A. enodis), elongate sawsheath and the middle annuli substraight; each serrula rounded very different shape of the penis valve. or subtriangular in outline; gap between 2nd and The species of the rejecta group (A. rejecta 3rd serrulae not much larger than gaps between and A. vulnerata) have a very similar color pat- other serrulae. Male genitalia (Figs. 8–10): tern to that of the captiva group, but differ in a Gonostipes in ventral view narrowed apically number of morphological features including the with apical width about as long as or longer than medially sharply carinate supraclypeal area, the basal width of harpe and with medial margin densely pilose outer margins of the wings, rather posteriorly subtruncate or roundly convex.