A diet of oak sawdust, agar, water, and nutrients was developed for rearing the carpenterworm, Prionoxystus robiniae (Peck). The larvae were reared in petri dishes and given fresh food as needed. Adults began emerging in 9 months and continued through the 23rd month. There were 2 peaks of emergence, 1 during the 11th month and a second during the 19th. Of the larvae, 59% pupated, and 88% of the pupae produced adults.