They work underground, puncturing the root to draw its nourishing juice,
causing the root tissue to expand into knots and irregularities, _a_,
fig. 20, thus making the roots unhealthy and very brittle. These insects
are often found in myriads, looking like bluish-white wool, on the
roots. Certain beetles, maggots and flies prey upon them, but to only a
small extent.
[Illustration: FIG. 20. Root-louse.]
_Remedy._ Scalding water, at 150 degrees, poured on the uncovered roots.
If some concentrated lye is added it is still better. Filling above the
roots with tobacco dust is recommended. Soap-suds and wood ashes are
beneficial. Young trees from the nursery, if infested, should have the
roots well trimmed (burn the trimmings) and then dipped in lye. If quite
hot it is still better.