1.   Canadian hemlock works well, but woolly adelgid attacks mean a high-maintenance obligation.

2.   Canadian hemlocks, a common hedging evergreen, are likely to be the next victim, thanks to the woolly adelgid aphid from Asia.

3.   It looks and acts a lot like an eastern hemlock but is somehow resistant to the woolly adelgid.

4.   Look for waxy white egg masses of woolly adelgid on hemlocks, and spray with horticultural oil when temperatures are above freezing.

5.   Mike Newman of the Lowden Tree Co. in Lincoln, Mass., first spotted the woolly adelgid here about six years ago on the Brookline-Newton line.

6.   Protect Eastern hemlocks from the woolly adelgid that skeletonizes these trees.

7.   Spray hemlocks again with insecticidal soap or horticultural oil for woolly adelgid.

8.   The Asian woolly adelgid insect is expected to burst into dozens of communities as early as spring.

9.   The appearance of a housing development on former oak savanna in California seems unconnected to the destruction of native hemlocks by a parasitic Asian insect called the woolly adelgid.

10.   The hemlock absorbs the poison without damage, and the woolly adelgid is killed.