The weekly Floridian. [volume] (Tallahassee, Fla.) 1867-19??, 1880-08-31


Il DEPARTMENT. on THE INTERIOR,
OyvIcR q. 8. METEOROLOGICAL Coannss1oR,
CnNTRRyTr1N, FLA, August ~, 1850.
Carr. O. e. DYxK, Edis0r F5OsSdian:
DEAR SR:-Mr T. J. Roberts has reminded
me Of promise that would give you some
notes Of the observations that have been made
here Of the caterpillar and Its doings have de-
layed doing % on account of some rather unex-
pecied developments in iis career at this point,
the result Of which has until lately been In doubt
and concerning which wished to assure myself
before writing 50
II has not been q part Of my work TO watch
the spread of the cotton worm over wide area,
or 70 report the extent of its depredaons In this
county, but rather to study Its habits and life
history, and to observe and study the enemies
that prey upon 1t. have therefore confined my
observations TO Mr.. Roberts plantation, and am
not sure that the same conditions exist elsewhere
About the first Of this month there was here
every indication that unless vigorous fight was
made BY the application of poisons q clean sweep
would be made by the caterpillar during the
month. Not only were there scattering webs
over the entire acreage, but in several places
patches OF five Or six acres were entirely ragged,
the fies had there appeared in great num-
bern. BY the sixth Of the month the flies were
seen everywhere about the plantation, and eggs
were laid by millions In every part of the cotton
fields. As the eggs hatch in from three to four
days, and the worms complete their growth in
about ten days thereafter, there was of course
every prospect that if left 10 itself the cotton
would be stripped by the middle of August. The
worms, however, failed 10 make their appearance
In any numbers, and there are now a few small
patches only where they can be found. Now
for the reason of this unlocked. for change in
the programme. The eggs of the caterpillar are
laid upon the underside of the lower leaves
When fresh they are transparent green in color,
resembling miniature emeralds and so minute
as to be very difficult to detect Ii number of
these eggs are gathered and kept few days in
tight box, nearly all of them will be found to
have turned black The few that remained green
will have Matched, and the young caterpillars
that came from them will be wandering about
the box. day or two later these black eggs
also give birth. not 10 young caterpillars, but
from each OF them energies two little Tour winged
flies They spring from the caterpillar egg, per-
feet in every part full grown, adult, ready to pro-
create and reproduce their kind but so infinitesi-
NAL in size that without the aid OF a microscope
they are quite invisible TO most human eyes,
This, then, is their history. The caterpillar egg
from which they came had been "siung" by a
mother fly like themselves In it she laid two
infinitely small eggs These Matched maggots,
which, by feeding upon the contents of the cater
nillAP CQnOad IN, m hlonL
devoured the contents of the egg in which they
were born, the two little maggots have reached
their full size. They then form their chrysas,
just as the caterpillar itself docs in its web upon
the cotton leaf and, still confined within the egg
that has sheltered and fed them, they change in
due time TO perfect and adult flies, eat their way
out and fly off to procreate and sting more cater
pillar eggs. Having thus reproduced their kind,
their mission is ended. and they die
On This plantation about ninety per cent of all
the caterpillar eggs laid have been thus stung
ana destroyed. The result is that the back bone
of this brood is broken, and as the caterpillar has
in its various other stages many insect parasites,
as well as enemies among the birds and other
animals, and as these become more numerous as
the season advances, the ten per cent. that do
hatch are nearly all devoured by their foes at
one time or another, so that of this remainder
even not one in thousand escapes and reaches
maturity.
The little egg parasite has been described by
Prof. Riley, who called II Tsichogramma pretiosa
1t may be confidently asserted that wherever it
is doing such effective work as il is now in this
neighbOrhood there need be no further fear of
damage by the caterpillar for this season. 1t
should he borne in mind, however, that not every
year will the planter have the aid of such an
effective ally, and the best advice that can be
given him is to store up his Paris green, London
purple and fountain pumps, to have them in
readiness for an early fight the following year.
A word and l have done. The researches of
the entOmOlogist have taught him that invariably
the most minute insects are the most effective for
good or for evil That was popular falacy ex-
pressed by the planter who said, appropos OF his
insect nionds and foes, he would "give little for
one that he could Ma see" Let us. cir not
"despise the day Of small ihInss Very sincerely
yours, W. G. HU.sARD.
Special Agent U. 8. EIr. Com