North American Fruit Explorers mailing list at ibiblio

["Robert Stanton" <robert.l.stanton@gmail.com>]

All,

As a cicada enthusiast, I can tell you that the best way to protect
your young trees from the periodical cicada emergence is to cover them
in the typical wrapping used to prevent birds or other insects from
accessing the fruit(s).

As Tom noted, oviposition on large trees is rarely a problem.  In
fact, to my knowledge, oviposition on young trees has not caused any
significant die-offs of trees, either.  The "pruning" (otherwise
called flagging) does tend to cause die-back of the branch to the
point of oviposition.
Cicadas have no chewing mouthparts; they suck sap from xylem tissue
using tiny stylet-like mouthparts.  Studies have been conducted on the
impact of cicadas on growth of vegetation, which has shown initial
results of some impact on vitality.  Other studies have demonstrated
that cicadas are important cyclers of nutrients at the secondary
trophic level and that their emergence provides food not only for
higher-level consumers, but also large amounts of "fertilizer" for
vegetation (as their bodies decay).

I would encourage those in the area of this brood's emergence (brood
XIV) to enjoy it and take appropriate procedures for trees if
necessary.  That is, bag trees you do not want to take any chances
with.  Using insecticides is largely ineffective at killing massive
amounts cicadas; their emergence tactic is to overwhelm responses such
as this (from predators).

The annual cicadas typically oviposit on dead wood and do not cause
the flagging periodicals do.  They are also significantly fewer in
number.

Nearly all periodical cicada broods are under some to significant
population pressure from habitat destruction.  One east coast brood is
likely to go extinct in our lifetimes.

Robert