Second discovery of the subdichthadiigyne in Yunodorylus (Borowiec, 2009) (Formicidae: Dorylinae)

摘要

The genus Yunodorylus comprises four named species known exclusively from the Indo-Chinese and Indo- Malayan subregions. The queen and male of the genus were unknown until recently. However, the subdichtadiigyne was fi rstly discovered from two colonies of Y. eguchii (Borowiec, 2009), and described by Eguchi et al. in 2016. Then, the present authors discovered a colony of Yunodorylus doryloides (Borowiec, 2009) with a subdichthadiigyne and herein describe the subdichthadiigyne. The subdichtadiigyne of Y. doryloides is morphologically similar to that of Y. eguchii, but it can be distinguished by the combination of the following morphological characters: mandible elongate and slender, with the edge behind the basalmost tooth of the masticatory margin almost straight; lateroclypeal teeth rounded; mesosoma in dorsal view slenderer in the former than in the latter; mesonotum in dorsal view distinctly longer than broad in the former, but almost as long as broad in the latter; anterior margin of mesopleuron without a small lobe; metanotal groove in dorsal view faintly recognized; ventral margin of metapleuron almost straight; petiole in dorsal view narrower and longer in the former than in the latter; pygidium apically without any specialized setae.