Evening star., 1936-06-11
STARS, MEN AND ATOMS
Notebook of Science Progress in Field,
Laboratory and Study.
BY THOMAS r. HENRY

Three years of complete starvation
and still healthy and vigorous.
Such is the record of the dog tick,
carrier of the dreaded spotted fever, in
the hands of Department of Agriculture
entomologists. Some adult ticks were
placed in vials on April 10, 1888, it is re-
ported by DR.. F. c. BiShopp, Govern
ment entomologist, and have been kept
without food ever since. They still are
healthy and vigorous.
This fact is of considerable significance
in estimating the difficulty of eliminating
the latest and one of the most terrible
foes of human life in the insect kingdom.
Until about five years ago the tick was
treated with contempt. Then it was
learned for the first time that it was
carrying the virus of the highly dam
gerous spotted fever in the East. Be-
fore that the disease had been confined
to the Rocky Mountains where it was
spread by related species of tick which
did not infest dogs. 1t is also poten-
TALLY the carrier of one of the wierdest
of human diseaseS-the so-called tick
paralysis of children which is q pro-
greSsively ascending paralysis invariably
fatal if allowed to continue, but which
can be stopped suddenly and completely
at any moment almost up to the time
of death simply by finding and picking
off the tick responsible for it.
The dog tick is one of the most ubi-
quitous of insects, so that its elimina-
tion offers an extremely difficult prob
lem. 1t passes one stage Of its existence
as "nymph" on such creatures as field
mice and ground squirrels in brushland,
and the most practical suggestion has
been to clear away the natural habitats
of these creatures. But even If this were
done at enormous expense, the Depart
ment of Agriculture experiment shows,
it might make little difference for several
years. The tick probably could wait
patiently three or four years until a
suitable meal, dog or man, came along.
Neither do extremes of weather have
much effect on the insects, DR.. Bishopp
finds. Last Winter was one of the coolest
of record in the East, but freezing seems
to agree with ticks. They now are un-
usually abundant. The other day a
hundred were picked off a single dog
after few hours in the woods They
are lurking on bushes everywhere. They
prefer dogs to men, but will condescend
to gorge themselves on human blood
when there is nothing better to be had.
Fortunately, DR.. Bishopp says, only a
small number of the billions of ticks
actually are infected with the spotted
fever virus. More are likely to become
carriers each year, however, and the dis
ease is widespread and has high NOR
tality. In the East infected ticks are
known to occur in Maryland, Virginia,
Delaware and North Carolina. Most of
the spotted fever cases thus far reported
have been from Maryland and Virginia.
There have been cases, however, in all
States in the East except in New Eng
land, Ohio, Michigan, Wisconsin and
Mississippi.
They now are at the height of their
abundance. Throughout the Summer
they will grow scarcer and scarcer until
by early August they viii have entirely
disappeared and camping trips and hikes
through uncleared woods will be safe.
In the meantime, the Agriculture De-
partment entomologists emphasize, it is
important to confine dogs in yards and
examine them frequently. Every tick
should be pulled OF dog with foreceps