Evening star., 1936-05-23
LOCUST PEST HERE
17-Year Escape From Darkness Marked by
Wild Chorus Science Puzzled by
Practice of Centuries.

makes the same noise when picked up
About a week or 10 days after
emerging the insects mate and a few
days later the females begin laying
eggs. The eggs are laid on twigs and
small branches. About 80 different
varieties of trees, shrubs and herbace-
GUS plants are listed as harboring
them. The females seem to have a
decided preference, however, for oak.
hickory and apple. Peach, pear and
grape sometimes are severely damaged
by the egg laying. Twigs in which
many egg pockets are made often are
broken from the tree and these broker,
twigs with their masses of Drowned
leaves are characteristic in woodlands
and orchards late in the Summer of
cicada year.
The female deposits the eggs on
paratus at the end of the abdomen.
With this she makes a pair Of pockets
near the surface Of the twig and de-
posits two. rows of eggs-24 to 28
altogether-in each pair of pockets.
She then moves forward, makes an
other pair Of pockets, and continues
until from to 20 of these twin
pockets are placed close together in
straight rows.
In one instance so pockets were
observed on one twig. Sometimes they
are so close together that they form a
continuous slit from two to three
inches long. A single female will
make several rows of such pockets on
different twigs and deposit from 400
to 600 eggs.
THE eggs remain on the twigs from
six to seven weeks before hatch
ing. During this time they are said
to absorb plant juice and become
larger. If a twig is killed before the
eggs are matured they will not hatch.
They normally start Matching in mid
July and continue into the early part
of August.
Then the worm-like nymph. in
closed in an embryonic membrane.
wriggles out of the egg shell. 1t sheds
the membrane, runs out on the
smooth bark and soon falls to the
ground. Then 1t burrows down until
it finds a suitable rootlet and there,
attaching its mouth parts, starts again
the long underground existence of the
species. 1t rarely moves from the cell
it constructs on first entering the soil,
but enlarges it from time to time to
accommodate its growing body. The
insects usually live from 18 to "a
inches below the surface. There are
questionable reports, however, that
they have been found at depths of
S feet.
During the II years Of its under
ground existence the insect under
goes five metamorphoses, or complete
changes of bodily appearance. For
the whole period it lives contentedly
in the warm, black darkness of its
subterranean retreat, sucking on the
juicy rsot to which it has attached
itself But as the II years draws
to an end it is gripped by a myste-
rious, irresistible impulse. About the
middle of April 1t burrows upward to
within about an inch of the surface.
There it constructs a more or less per-
pendicular tunnel, in which 1t re-
mains until time for emergence.
In excavating such q tunnel the
loosened earth is pressed into the side
walls, thus obviating the necessity for
opening the burrows to the surface.
The tunnels are from to 8 inches
long and little more than . half
inch in diameter.
The cicadas are weak, almost de-
fenseess creatures, i'll adapted to cope
with their natural enemies. But dur
ing the entire period OF their sub
terranean existence they are COM
pletely protected. Only for q few
weeks at the most, over II years, must
they expose themselves-and this at
the very end Of the life cycle of the
individuals.