Evening star., 1941-05-05
japanese Beetles
To Get 500,000,o00
Unwe|come Visitors
Nemutodes to Be Taken
To Infested Maryland
Areas to Fight Pest


Japanese beetles now resident in
Maryland are going to have some
unWelcome visitors. The veal-eating
nematodes-5O0. COO 900 of them-are
on the way.
They were received informally to-
day in the chronological laboratories
at the University of Maryland and
prepared for distribution in the
States tidewater country and ad-
jacent areas to appropriate the
homes and even the bodies of jap
anese beetles.
Nothing drains beetle of ambi-
ton so thoroughly as a nematode,
except a nasty parasitic wasp named
typhia vernalis and the milky white
disease. The pests established in
Maryland now will be forced to con-
tend with all three. A nematode
likes veal, but when deprived of this
luxury laboratory diet will settle for
a piece of beetle. The parasite
usually enters the body of a grub,
but also is known to attack the
adult beetle as it is leaving the
pupal case and emerging from the
ground. For a change OF diet,
nematode will sample any one of
Is other undesirable insects.
A Little Fellow.
Entomologists paid scant atten-
ton to the little fellow-a wire
worm ranging in length from IL to
2.87 millimeters-until New Jersey
State laboratory discovered its eat
ing habits about five years ago.
Propagation was undertaken by the
State, and colonies were established
in beetle-infested locations.
DR.. E. N. Cory, State entomologist;
DR.. George S. Langford, State insect
control officer, and their associates
plan to undertake a similar dis
tribution program in Maryland, de-
posting the nematodes in plots OF
Is. so and 1000 square feet at the
rate of 5000 to the square foot.
The unfortunate beetles do most
of the work of spreading the para
sites, DR.. Cory explained yesterday.
They live only a short time after
being attacked by nematodes, and
when they settle to earth and die
the wire worms enter the ground
again, establishing a new colony.
The latter also spread about on
their own initiative to some extent.
Warns of Over Optimism.
DR.. Cory cautioned farmers and
gardeners against over optimism.
however, pointing out the men striv-
ing toward control of the japanese
beetle in Maryland do not expect
appreciable success for three to five
years. The milky white disease still
is considered the most effective
enemy of the pest, he said, but the
nematode and parasitic wasp are to
be used extensively this year as
parts of the biological complex"
For the information of home
owners who feel a few hundred
thousand nematodes Cor neoplectana
glaserD would be valuable in pro-
tecting the foliage around the house,
the entomologists offer this dis
couraging information:
The propagation begins with col
lection of infested beetle grubs. a
simple chore if one can identify in
tested beetle grubs and knows where
to find them in quantity. Waiting
for the beetles to die is the next
step. Then the cadavers are placed
in small petri dishes available at
the nearest laboratory supply house)
and cultured on a suitable
medium" for the formula of which
the insect control experts at the
University of Maryland might be
approached (but they hope not.
The Next Steps.
When the cultures increase in
size, they are transferred to larger
dishes and finally to trays filled with
macerated veal. The trays, measur-
ing 18 by "a inches and containing
millions of nematodes each, are kept
at a temperature of 10 degrees for
about week.
The nematodes are very sloppy
eaters, so they must be washed free
of veal particles in an isotonic salt
solution. Next, they are placed for
storage in five-gallon bottles OF
water and agitated constantly by
compressed air. The worms seem to
enjoy this and keep in excellent
condition for a long period.
Dr.. Glenn to Preach at V.M.l.