T ISHIKAWA

Tokyo University of Agriculture, Japan

THE THREAD-LEGGED ASSASSIN BUG GENUS (: ) 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 Resources, Faculty of Agriculture, Tokyo University of Agriculture, Funako 1737, Atsugi-shi, Kanagawa, 243-0034 Japan. E-mail: [email protected] Key words. – Heteroptera; Reduviidae; ; ; 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 T  E,  148, 2005

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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.

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