Larvae feed gregariously for five weeks and cocoons are formed in mid-May, with adults emerging at the end of May. Larvae from the second generation emerge in June and form cocoons during late July to early August. Pre-pupae remain inactive in the cocoons until late fall. Adults emerge in November and deposit their eggs. Since the host plant species are not widespread in Virginia, there is little need for use of active control strategies. Where hosts are abundant, outbreaks of the blackheaded pine sawfly occur periodically and usually subside rapidly.
Factors contributing to the quick decline in sawfly populations are starvation and natural enemies.
Insects and Diseases of Trees in the South. Protection Report R8-PR16. Doggett, C.A. 1972. Notes on the biology of Neodiprion excitans in North Carolina. Drooz, A.T. 1985.