T ISHIKAWA Tokyo University of Agriculture, Japan THE THREAD-LEGGED ASSASSIN BUG GENUS GARDENA (HETEROPTERA: REDUVIIDAE) FROM JAPAN Ishikawa, T., 2005. The thread-legged assassin bug genus Gardena (Heteroptera: Reduviidae) from Japan. – Tijdschrift voor Entomologie 148: 209-224, figs. 1-55. [ 0040-7496]. Published 1 December 2005. Five species of the reduviid genus Gardena are recognized in Japan. Two species, G. albiannu- lata sp. n. and G. boninensis sp. n., are newly described here. Detailed descriptions and illustra- tions of male and female genitalia are provided for all species. Correspondence: Tadashi Ishikawa, Laboratory of Insect Resources, Faculty of Agriculture, Tokyo University of Agriculture, Funako 1737, Atsugi-shi, Kanagawa, 243-0034 Japan. E-mail: [email protected] Key words. – Heteroptera; Reduviidae; Emesinae; Emesini; Gardena; Japan; new species. Gardena Dohrn, 1860 is the second largest genus are limited to a few species only. in the tribe Emesini of the reduviid subfamily In the present paper, Gardena of Japan is revised, Emesinae, comprising 46 species from all zoogeo- with descriptions of two new species. A diagnosis and graphical regions (Maldonado Capriles 1990). In illustrations of male and female genitalia, including Japan, the genus was represented by three species up the struts and styloides, are provided for all Japanese till now: G. melinarthrum Dohrn (type of the genus), species. A key to the Japanese species is also given. G. brevicollis Stål and G. muscicapa (Bergroth) (Putshkov & Putshkov 1996). Recently, however, M five species of the genus have been recognized through field surveys made by my colleagues and me Dried specimens of each species were used. All il- and by investigations of reduviid collections housed lustrations are based on specimens collected from at several institutes in Japan. Three of them belonged Japan, except that a male specimen of Gardena to the previously known species, mentioned above. melinarthrum from Malaysia was used for illustrating The other two were found to be undescribed, one the genitalia (figs. 26, 31, 36). Claws of forelegs and from the Ryûkyû Islands and the other from the male and female genitalia were macerated in a hot Ogasawara Islands. 10% solution for about five minutes. The endo- Discrimination among species of Gardena has been soma was pulled out of the phallosoma under based on a combination of several morphological a stereoscopic dissecting microscope with forceps. characters, such as the structures of head, pronotum Illustrations of claws of forelegs and male and female and forelegs. Genitalia present valuable information genitalia were drawn with the aid of an optical micro- as well, such as the shape of the genital capsule, para- scope equipped with a drawing tube. The endosoma meres and endosoma of phallus, which are frequently was omitted from the illustrations of the phallus be- very useful in other genera of the Emesinae as well as cause it hardly represents distinguishing features for in many other reduviid groups. Careful study of the at least the Asian species of Gardena. After observa- genital morphology of Gardena revealed that the tion, these parts were preserved in small glass vials shape of struts in the male and that of styloides in the with glycerol. female provided useful information for distinguishing Terminology generally follows that of Wygodzinsky the species. Although Wygodzinsky (1966) has pro- (1966), but terms for the male and female genitalia vided illustrations of these structures for the genus in mainly follow Davis (1966). All measurements in the his monographic work of the world Emesinae, these text are given in millimeters. Depositories of the 209 Downloaded from Brill.com10/02/2021 09:38:14PM via free access T E, 148, 2005 1 2 3 4 5 Figs. 1-5. Gardena spp. – 1, G. melinarthrum, female; 2, G. brevicollis, male; 3, G. albiannulata sp. n., male (holotype); 4, G. muscicapa, male; 5, G. boninensis sp. n., male (holotype). Scales: 5.0 mm. 210 Downloaded from Brill.com10/02/2021 09:38:14PM via free access I: Gardena in Japan material are abbreviated as follows: Type depository: unknown. Entomological Laboratory, Faculty of Agri- Gardena melinarthrum var. femoralis McAtee & Malloch, culture, Ehime University, Matsuyama 1926: 136. Type locality: Kuala Tahan, Pahang, Malaysia. Entomological Laboratory, Faculty of Agri- Type depository: Museum of Natural History, London. culture, Kyushu University, Fukuoka Department of Zoology, National Science Diagnosis Museum, Tokyo Recognized by the brownish yellow to yellowish Omogo Mountain Museum, Ehime brown body, the pronotum 2.7 times as long as the Dr. S. Miyamoto’s personal collection, head and lacking a transverse sulcus at the border of Fukuoka the anterior and posterior lobes (figs. 6, 7), the un- Laboratory of Insect Resources, Faculty of spined basal portion of the fore femur 0.32 times as Agriculture, Tokyo University of Agriculture, long as the whole length of the fore femur (fig. 16), the Atsugi foretibia less than the half length of the fore femur (fig. Abbreviations are also used for several collectors of 16), the outer claw of the foreleg with four triangular the material as follows: : Keiichi Matsumoto; ventral projections (fig. 21), the struts of the phallus : Katsuyuki Ohgi; : Kazutaka Yamada; thickened moderately at the basal portion (fig. 36), : Mikio Takai; : Syoiti Miyamoto; : Seidai and the female styloides with a weakly concave poste- Nagashima; : Shinji Yano; : Tadashi Ishikawa; rior margin (fig. 43). Body length 20.0-26.0 mm. : Toshio Kishimoto; : Masaaki Tomokuni. Description of genitalia Male. – Pygophore (fig. 26) evenly expanded ven- T trally in lateral view, with posterior process; posterior process (fig. 26) erect, weakly curved posteriorly, Genus Gardena Dohrn rounded at apex. Parameres (fig. 31) gently curved in- [Gardena Dohrn, 1859: 252. Nomen nudum.] wards, rounded at apex, with erect and suberect setae; Gardena Dohrn, 1860: 214 (n. gen.), type species by mono- these setae as long as or shorter than maximum width typy: Gardena melinarthrum Dohrn, 1860. Lutevopsis Champion, 1898: 165, type species by subse- of paramere. Phallosoma of phallus (fig. 36) sclero- quent designation (Kirkaldy 1907: 249): Lutevopsis tized on dorsal and ventral surfaces; struts (fig. 36) longimanus Champion, 1898 (syn. by Wygodzinsky slender in apical four-fifths and moderately thickened 1966: 246). in basal one-fifth in lateral view. Female. – posterior margin of abdominal tergite This genus is easily recognized by a combination of VIII arcuate posteriorly (fig. 41). Tergite IX about the following characters: the rostral segment I appar- 1.5 times as long as tergite VIII (fig. 41). Valvifers I ently shorter than the segment II, the scutellum not (fig. 42) large; valvulae I (fig. 42) curved inwards, spined or tuberculate, the anteroventral series of fore acute at apex. Styloides (fig. 43) discally elevated, car- femora composed of delicate spine-like setae or very inate ventrally along meson, covered with erect setae small spines only, the three-segmented fore tarsi, the along and near lateral margins, and with weakly con- hemelytra each with a single cell, and a single vein cave anterior and posterior margins. (M+Cu) extending basad from base of a discal cell. Wygodzinsky (1966) provided a detailed description. Distribution Wygodzinsky (1966) divided this genus into Japan: Honshû, Shikoku, Kyûshû, Yaku-shima four species groups, the melinarthrum, brevicollis, Island, the Ryûkyû Islands (Okinawa-hontô Island); longimana and pipara groups, based on external Taiwan, Korea, China, Sri Lanka, Philippines, morphology of legs and male genitalia. Among the Malaysia, Indonesia, Australia. The records from Japanese species, G. melinarthrum belongs to the Honshû and the Ryûkyû Islands are uncertain be- melinarthrum group and the others, including two cause the material could not confirmed through the new species described below, are associated with the present study. brevicollis group. Remarks This species is very rare in Japan. Previous records Gardena melinarthrum Dohrn from various areas of Japan, including Shikoku and (figs. 1, 6, 7, 16, 21, 26, 31, 36, 41-43) Kyûshû, seem doubtful in most cases, because large Gardena melinarthrum Dohrn, 1860: 214 (n. sp.). Type specimens (mostly female) of G. brevicollis have often locality: Sri Lanka. Type depository: unknown. been misidentified as G. melinarthrum. According to Gardena semperi Dohrn, 1863: 64 (syn. by McAtee & Malloch 1926: 136). Type locality: Luson, Philippines. Dr. S. Miyamoto (pers. comm.), however, this species had frequently been found at Fukuoka before 1970. 211 Downloaded from Brill.com10/02/2021 09:38:14PM via free access T E, 148, 2005 6 7 8 9 10 11 12 13 14 15 Figs. 6-15. Head and prothorax, dorsal (6, 8, 10, 12, 14) & lateral (7, 9, 11, 13, 15) views (setae omitted). – 6, 7, G. melinarthrum, female; 8, 9, G. brevicollis, male; 10, 11, G. albiannulata sp. n., male (holotype); 12, 13, G. muscicapa, male; 14, 15, G. boninensis sp. n., male (holotype). Scales: 1.0 mm. 212 Downloaded from Brill.com10/02/2021 09:38:14PM via free access I: Gardena in Japan Material examined. – : Shikoku: Kôchi-ken: (fig. 45) large; valvulae I (fig. 45) curved inwards, Tachikawa, Ôtoyo-chô: 1& (shown in figs. 1, 6, 7, 16), acute at apex. Styloides (fig. 46) discally elevated, car- 31.viii.1992, T. Ohno ( ); Nakasuji Dam, Sukumo-shi: inate ventrally along meson, covered with erect setae 1& (shown in figs. 21, 41-43), 27.ix.1997, T. Befu (). – Kyûshû: Fukuoka-ken: Chikuzen: 1(, 15.ix.1955, along and near lateral margins in apical half, and with (); 1(, 15.ix.1956, , with labels “Gardena meli- gently concave anterior and posterior margins. narthrum Dohrn ? var. femoralis McAtee & Malloch, det. Wygodzinsky” and “3” (). – Yaku-shima Is.: Aiko-dake Distribution (more than 400 m alt.), Kamiyaku-chô: 1&, 4.x.1969, Japan: Hokkaidô, Honshû, Shikoku, Kyûshû, K. Kanmiya ( ). – : 19 miles from Tapah, Okinoshima Islands, Tsushima Island, Yaku-shima Cameron Highlands: 1( (shown in figs. 26, 31, 36), 9.iv.1996, ().