none Microctonus pachylobii adults emerged in the laboratory from field-collected pine root tip weevils, Hylobius rhizophagus and pales weevils, Hylobius pales . This is the first report of M. pachylobii parasitizing a species of Hylobius , and the first known hymenopteran parasite of H. rhizophagus, Microctonus pachylobii is also reported from Wisconsin for the first time.