A new species of the genus Himertosoma from the Ryukyus, Japan, with a key to species from the Palaearctic and Oriental Regions (Hymenoptera, Ichneumonidae, Banchinae)

Kyohei Watanabe,Kaoru Maeto

doi:10.3897/zookeys.234.3794

Abstract

A new species of the genus Himertosoma Schmiedeknecht, Himertosoma kuslitzkii sp. n., was discovered in Amamioshima Island, the Ryukyus. This new species resembles two Oriental species, Himertosoma philippense Chandra & Gupta and Himertosoma townesi Chandra & Gupta, in the colour pattern of the head and metasoma, number of flagellomeres, and the relatively slender first metasomal tergite, but can easily be distinguished from them by the nearly evenly punctate propodeum, different length/width ratio of the first metasomal tergite, different length of the ovipositor sheath, tricoloured mesosoma, and the whitish band along the posterior margin of the second and following metasomal tergites. A key to the Palaearctic and Oriental species of Himertosoma is also provided.

Highlights

Himertosoma Schmiedeknecht, 1900, is a large genus in the tribe Atrophini of the ichneumonid subfamily Banchinae, containing 58 described species (Yu et al 2012)
In addition to H. uchidai from Kunashiri Is. (Kuslitzky 2007), we found a species of Himertosoma from Japan, collected on Amamioshima Island, the Ryukyus, which is described here as new to science
We describe the new species based on only a single specimen, for the three following reasons: 1) the specimen is in good condition, 2) we made intensive collecting efforts in the type locality and checked all major collections of Japanese ichneumonids, but we have not found any more specimens, and 3) we know that the ichneumonid fauna of the Ryukyus contains some biogeographically important species such as relict or endemic species (e.g., Watanabe et al 2010; Matsumoto and Broad 2011)

Summary

Introduction

Himertosoma Schmiedeknecht, 1900, is a large genus in the tribe Atrophini of the ichneumonid subfamily Banchinae, containing 58 described species (Yu et al 2012). Four species have been known from the Palearctic and Oriental Regions; H. superbum Schmiedeknecht, 1900 (type species) from Egypt, Israel, Syria and Uzbekistan, H. uchidai Kuslitzky, 2007 (= H. sulcata Kuslitzky, 1995) from Far East Russia and Japan (Kunashiri Island), and H. philippense Chandra & Gupta, 1977 and H. townesi Chandra & Gupta, 1977 from the Philippines. (Kuslitzky 2007), we found a species of Himertosoma from Japan, collected on Amamioshima Island, the Ryukyus, which is described here as new to science. A key to all the described species of Himertosoma from the Palaearctic and Oriental Regions is provided. We describe the new species based on only a single specimen, for the three following reasons: 1) the specimen is in good condition, 2) we made intensive collecting efforts in the type locality and checked all major collections of Japanese ichneumonids, but we have not found any more specimens, and 3) we know that the ichneumonid fauna of the Ryukyus contains some biogeographically important species such as relict or endemic species (e.g., Watanabe et al 2010; Matsumoto and Broad 2011)

Materials and methods

Discussion