The ranch. [volume] (Seattle, Wash.) 1902-1914, 1908-09-15

taIlOh'
T suppose the colony of ants referred
~ by Prof Cox is what is known as
the Mound-Building Prairie Ant (Pog-
onomyrmex occidentalis Cresson). 1t
NAV be some other species. But so
far as the destruction of these pests
10 concerned it does not make much
Inference whether we classify them
nroperly or not. To get rid of these
ants that burrow in the ground the
treatment is the same. So far as l
know, there is but one sure remedy
tor these pests, and that is fumigation
with carbon bisulfide. But it is essen
tial to success with this insecticide
that we know something of the habits
of these pests, or otherwise we may
fail. A partial destruction of the col
onv will not answer, for so tenacious
are these ants for their home that
they will not desert it while one is
alive. They are wonderful fighters,
and being armed with stings (the fer
tue females and workers) almost as
powerful as the common honey bee,
they can maintain their ground against
almost any foe. If only few of the
fertile females are left, they will soon
build up another strong colony. The
workers are all females, but like
workers among bees they are non-fer-
tile. 1t is claimed by our most compe-
tent entomologists that every one OF
these fertile females, frequently called
queens, must be killed or in time the
colony will grow to be strong enough
to be a serious pest. Before the fumi-
cation begins, we must be sure that
the opening or openings to the nests
are not closed. These ingenious lit
tie workers close up all openings at
night; they also close up the openings
on the approach of rain. If these
openings are closed the fumigation
will not be effective. The best thing
[ have ever seen on the method of
getting rid of these ants l quote as
follows from a bulletin issued by the
Kansas Experiment Station:
Our study has shown no natural en-
envy of sufficient Importance to war
rant hope of material help from such
a source, but has clearly indicated that
artificial remedies must be employed
to give relief.
In view of the tenacity with which
the ants cling to their nests, it is clear
that successful treatment requires the
complete determination of the repro
ducing members of the colony, and,
as some of these are to be found in
the lowest chambers, it is also plain
that every ant in the nest must be
killed. Any method of treatment is
therefore successful only in SO far as
this end is attained.
Carbon bisulfde. Many methods
have been given thorough trial, but
fumigation with carbon bisulfide is
the only one that can be labeled sue
cessful" according to this test. Car
bon bisulfide is evaporated under
practically alright vessel over one
or more of the opened gateways OF
the mound. The vapor formed, being
heavier than air, sinks downward
through the burrows into the lowest
parts of the nest and finally comes to
fill every chamber and passageway.
Thus all the ants that are at home are
suffocated. Many nests so treated
were carefully opened to the lowest
chambers and all the occupants found
dead beyond possibility of doubt. Some
nests were not opened until the next
day after the fumigation and then not
a living ant could be found.
me following moCHou VI uSlHS Col
bon bisulfide has proven the easiest
and most efficient tried. Start fuml-
cation when gateways are open; take
a vessel, such as galvanized iron
washtub, and place it bottom side up
in such a manner as to cover the open
ings and as much of the mound as
possible; if there are more openings
than the tub will cover they should be
closed by throwing some of the sur
rounding soil over them; place under
the tub, in a shallow pan or dish, near
the opening, one to three ounces OF
carbon bisulfide, depending on the size