AUGUSTA — The Maine Forest Service is releasing more predator beetles in southern Maine to fight hemlock woolly adelgids, which kill eastern hemlock trees.

Officials said today that about 9,000 laboratory-reared beetles are being released this week and next week in Saco and York in areas where they haven’t previously been released.

There are about 160,000 acres of hemlock-dominated forest in southern-coastal Maine.

The Maine Forest Service began releasing the beetles in 2004, and nearly 27,000 have been released to date. The beetles feast on hemlock woolly adelgid adults and their eggs.