The Washington herald., 1907-03-03

developed by the department IL Is pref
ty sure to stand the practical test of
actual cultivation, which is the main
thing.
Fighting the WeeViI Direct.
The Guatemalan ant, which eats wee
Wis. is not a parasitic enemy-thst is,
one which lays its eggs in the weevil. :
larvae. which then produce the parasite.
aud not the matured weeviI-but pre-
dacious enemy.
There are in Central America. however,
certain parasites which destroy weevils
by the million, and there was some hope
that they might be made valuable in the
United States. That hope proved ground
less. but curious thing happened a few
years ago when the cotton fields Of Tex
as developed their own cotton boil weeviI
parasites, in the shape Of two varieties
OF flies. called chaicids by the scientists.
This was altogether unexpected and al
together welcome. The flies are minute
creatures, not more than One-tenth as
large. as the weevils. In some way the
female chalcids, which from the begin
ming have been IN the habit Of laying their
eggs in the larvae of the sO-called straw
berry weevil. have found out that the cot
ton boil variety is much the better hatch
ing place for chalcid eggs The mother
flies didn't discover this all at once, but
gradually here and there all over the Wee
vii infested districts of Texas.
When Hunter and his men who are
fighting the weevil direct learned about
the chalcid's discovery, steps were taken
forthwith 20 extend the habit OF nesting
a., hill
way only. When the chalcid flies of any
given locality develop a tendency TO shift
from the larvae Of the strawberry wee
vii TO that of the cotton boil weevil, the
fact is at once apparent from the de-
crease of the weevils
When this fact is communicated to
Hunters men they collect as many Of
the chalcid flies rs possible in the proper
localities, and distribute them in other To-
calities. where the flies have not learned
the advantages Of the weevils' larvae as
nesting places. The successful transpor-
tation OF such a colony of educated
chalcids to a location where the Chalcids
are not so knowing is sometimes produc-
tive of satisfactory results the same sea-
son, since the chalcid flies propagate quite
as rapidly as the weevils which is re-
markable Mr. Hunter estimates that a
female weevil that lives through an en-
tire season. as some kept under observa-
ton have been known to do, produces l.
334OC0 individual weevils.
flinders Development.
Once a chalcid egg is deposited within
the body OF weevil larva it is certain
that the latter will never develop As
soon as the egg of the fly matches out
the grub begins at once to feed upon the
substances of the body with which it is
surrounded, and of course. the weevil
larva never develops. hut dies. Undoubt-
edly the transformation of the chalcid
Fly of this country into Il parasite of the
Weevil will ultimately mUve one of the
most important agencies for the keeping
of the bug in check. quite as effective, IN
fact, as the relative severity of the win
tiers. The great dryness of the summer
climate in parts of this country is also
beginning TO tell on the weevil. It seems
TO need humidity almost as much as It's
enemy, the GuatemalaR ant Dead and
dried up weeyils are often found by the
thousands among the cotton bolls, of Ok
lahOma in unusually dry seasons.
Mr.. Hunter dev0tes the entire season.
from cotton planting to picking time. each