The weekly clarion., 1880-04-21
COTTON INSECTS.
Compiled from Prof. Riley's Report
by Prof. Jones, Mississippi Univer-
sity.
WEATHER.

Warm wet weather favors the production
and development Of the worms. In ex-
trfwely dry weather, the eggs often times
much less active and on dropping to tie
ground are 50 affected by the heated surface
that they are unable To ascend the plant.
Many Of the chrysalides fail to form the
moth; when the moth i formed its supply
Of food is limited because the glands Of the
cotton plant in dry weather secrete much
less saccharine matter, and thereby it.
fecundity Is diminished All these effects
are intensified in prolonged drouth.
=. The natural enemies Of the Cotton In
sect are far more efficient in destroying it in
dry than in wet weather This Is particu-
larly true Of birds and ants
3. Wet weather Is unfavorable to the
poisoning Of worms and prevents the work
ing of cotton, which working helps to de
stroy the worms.
NUMBER OF BROOD5 IN a YEAR.
The common opinion has been that there
are three generations or "crops" in a season,
but in the Southern part Of the cotton belt
there are often as many as serea. Toward,
the middle Of the season, it becomes al
most impossible to distinguish the success
sive generations, inasmuch rs the insect j.
found in the same field, at the same time, in
all the stages of existence and growth from
the newly deposited egg to the full grown
moth.
The third generation under favoriug con.
ditions, may become widespread and disas-
trous. This generation appears in South
Texas abou. the latter part Of June; some-
what later in South Mississippi. This third
brood Is often thought to be the first; the
first and second having escaped observation.
Oftentimes backbirds and rice birds, which
are abundant in the cotton fields III June,
deyour large numbers Of cottom-worms ana
moths, thereby greatly Diminishing the
rate Of multiplication. The ants also in ta-
vorable seasons destroy many; ants feed on
the plant lice early in the season when the
weather grows very warm the plant lice
disappear, and then the ants looking for
new food, attack eggs and worms of the cot
ton insect. In very warm weather the birds
above mentioned emigrate The number Of
broods diminish as we 20 northward within
the cotton belt.
1mGRATIoNs AND POWER OF FLIGHT OF
THE MOTH.
Many persons, noting the short ard
clumsy though rapid and darting flight of
the moth, when disturbed during the day
time. get the idea that it is incapable of ex-
tended flight. But it has great power OF
wing, and its migrating habits are abund-
autly attested. 1t has been obseT ,ed in
numbers, far out at sea, and captured in au-
tumn off the coast of New England, around
Chicago and around BufIalo-the species be-
ing identified by competent entomologists
like Packard, Burgess, Grote and Westcott
/ have known it to do considerable injury
during September to peaches in Kansas,
and 10 ruin acres of cantelopes during the
same month far north Racine, Wis
That it Is aided in these distant flights by
favoring winds there can be doubt, but that
il does not depend on them for dispersion Is
equally certain.
DIR. ID. L. Phares records the destruction
by worms, of cotton the first year planted,
eighty miles from any point where cotton
had been grown before; while Mr.. II. +.
Bee shows that they appeared on cotton
planted two hundred miles from any other
fields Numerous similar cases might be
mentioned
The migrating habit is common to many
insects and other animals, but is almost al +
ways associated with excessive multiplica-
ton. Such Is likewise the case with the
cotton insect, (Aietia,) as the observations
of the past year have clearly shown. So
long as the worms are not numerous enough .
to materially riddle the cotton, the moths .
produced from them busy themselves with .
ovipositiug in the neighborhood where they
were born. spreading only comparatively .
short distances on all sides but whenever .
the cotton is well ragged" then the moths
ACQUIRE the migrating habit, and appear in
numbers everywhere-in town and village
and at lights far away from cotton-tields .
The time Of year when this migrating habit
is acquired varies, but it is Is rarely till af-
ter the third generation OF worms or the
latter part of June and fore part Of July in
South Texas; while it is most pronounced
during the autumn months. Atsuch times.
the moths may be noticed, during cloudy
davs. ztarting off by rapid flight and ascend
ing high in the air till lost To sight and the
contrast between this movement and the
dartng and hiding of the normal day-hight
is quite striking to any one who has wit
messed it. i