The larva of Rhogogaster genistae can be identified easily. It lives on Broom exclusively, is rather light below and greyish blue on top. We have not been able to find one single picture of an adult. The internet turns blank and so do the books we have. Even information about this species is very hard to find. Fact is that males are very rare indeed. It is suggested this species partly reproduces parthenogenetically. This sawfly is also known as Cytisogaster genistae. It is doubtful though whether this new genus will be long-lived, for apparently lot of scientists do not agree in using a new genus.