1991 Volume 1 Issue 2+3 Pages 155-162
In 1990 a large eumenid wasp was found on Chichi-jima, Bonin (Ogasawara) Islands. In structure, the wasp well agrees with Bequaert's (1928) concept of the wide-ranging "Eumenes pyriformis" (nowa species of Delta) in both the male and female. However, its color pattern is quite distinctive, easilydistinguished from those of al1 the geographical races of D. pyriforme so far known. Nevertheless, this wasp is considered to have been introduced from somewhere in the South Pacific or Southeast Asia, since no one had seen or collected it unti1 1990. It has now established itself on Chichi-jima and perhaps also on Ani-jima, though not seen on any other island of the Bonin group. Descriptions of the both sexes of this wasp are given together with notes on taxonomy and nesting biology.
