Evening star., 1933-02-26
M|LL|PED MAKES
CRADLEF0R YOUNG
Unknown Phenomenon Found
Near Washington Through
Accident.
BY THOMAS r. HENRY.


A queer insect that builds wooden
cradles for her unmatched young
something hitherto unknown In the
animal worlds found along the Po-
tomac near Washington.
It's curious behavior, discovered by &C.
cident. is described in . report to the
Washington Academy of Sciences by DR..
H. T. Loomis Of the Bureau Of Plant
Industry.
This insect is one Of the mflipeds or
"thousand-legs," several species OF
which are found in this area. 1t was
found on Plummers Island, the wild
life preserve maintained by Washington
biologists in the Potomac near Great
Falls. Hitherto its strange egg-laylng
behavior has been unohserved because
this has taken place in rotten wood un-
der the bark Of fallen trees. The egg
laying takes place only for q short time
once or twice a year. A local biologist
accidentally pulled of . strip Of bark
and surprised the mother millipeds at
their task.
Observation showed that the insect
first chewed up a quantity Of wood,
leaves and possibly fungus so that 1t
formed a paste. She would take a
small pellet Of this paste and pass 1t
back from her mouth to her eighth or
eleventh pair Of legs. Then, holding 1t
firm, she would twist around and bump
the pellet with her head until 1t took
on a saucerlike shape. In this saucer
she would lay single egg. As soon as
the egg was deposited the edges Of the
saucer would be turned up with the legs
and kneaded together until the egg was
inclosed in a ball. One milliped. it was
observed laid 2l6 eggs at one stretch,
making a saucer for each.
Then it was found the eggs Matched
within the closed ball and the young
millipeds ate their way out, process
which required altogether from three to
five weeks. The purpose Of the cradle"
was not only to protect the newly
hatched larvae, but also to PROVIDE
them with plenty of food from the start.
The paste from which the pellets were
made was believed to be the ideal food
for them.
Within this cradle. which 1t steadily
Is eating away, it is found that the
young milliped passed the first two or
three stages of its life. 1t emerges
from the egg tiny, white. legless,
Wormlike creature, and reached matur-
ity by undergoing eight or nine trans
formations, after each OF which 1t mas
larger eQulttlllCIlL Va 4CSo. ~ AAe.o Aoe.
ally developed about IL pairs when 1t
emerges from the pellet.
The curious behavior OF the mother,
as described in the report, Is considered
an almost perfect development OF an
insect instinct which, so far as known,
does not show itself in any other spe-
cies. although many insects have the
habit of laying their eggs In material
which will furnish food for the newly
born. Some wasps. for example. lay
their eggs in caterpillars after first par
alyzing them with a puncture OF the
nervous system which insures that they
will remain alive but motionless and
helpless. The young of such wasps
can survive only on living meat.
Other millipeds whose behavior has
been studied do not have this cradle
making practice, which apparently Is
restricted to this single secretive spec
cies. Some of them, however, form
nests In rotten wood in which to lay
their eggs. This species Is common
about Washington.
Mr.. Loomis was able to watch the
phenomenon for an extended period by
transferring some Of the egg-laying mil
Iipeds from the fallen log to tin can
with its bottom covered with damp, rot
ting wood, and found that the egg lay
ing and Matching process vent on in the
same way, but at slightly different
rate