St. Landry democrat., 1884-07-12
Our Foreign Cabbage Pest.

ciOuS imported insects, lHucl 1lioIe u0-
structiye in this country than in its aboo-
riginal home. Cur own native AmerI-
can cabbage butterflies the Northern
(Pieris oleraceu) and the Southern
(Pieris PY0todice) though sometimes
quite troublesome, are harmlessness
itself compared with the destructive tor
eign variety. -.
The male imported butterfly is white,
with tire tips of the fore wings black,
busted with white. On each Of the fore
wings there is q black spot. The female
butterfly has two spots on these wings
about tWo-thirds of the distance from
the base to the outer. edge Of the wing.
The eggs of this insect are laid singly
on the under side of leaves. The cater
pillar is green, with a yellowish stripe
down the back, and another along each
side, the belly being a paler, brighter
green. The body is so densely covered
with minute hairs as to have a velYety
appearance. The worm is often more
than an inch long, and about the thick
ness of a large croW-quill.
Wherever it has made its appearance,
the ravages of this pest have been very
great, amounting in money value to
hundreds of thousands of dollars annual
", in localities where the cabbage Is
largely cultivated.
A number of ways of thWarting the
destructive designs of the Pieris rGpae
have been suggested, one of the most
effective of which is said to be hand
picking when the caterpillar can be
seen, and the capture of the butterflies
by means of light gauze net mounted
on a wire ring a foot in diameter, at
tached to short pole. Where the cab
baoe head is badly infes ed, however,
it is best to root it mp and burn it on q
hot fire, so as to make sure that none
Of the worms escape. Busting the cab
bage early in the morning and evening
with lime Stacked in water in which
carholic acid has been dissolved is also
h ghly recommended as a means OF
driving the worm away. The lime
should be in the form of q fine dry pow
der. Mr.. Quinn has found carbolic
powder (so-calIed), superphosphate and
lime mixedtogether an effective appli-
cation. The american E12t0naol0gtSt re-
CARDS pyrethrum as the most satisfacto-
~ remedy 50 far discovered. 1t has
the further and important advantage Of
beng a perfectly harmless application
for all cabbage consumers except in
sects. Bran and buckWheat flour dust
ed over the infested plants as soon as
the worms make their appearance have
been found ef1ectual in some cases.
TIL Sc last-named remedies must be APP
led when the worms are young. A
second application IS sometimes neces-
sary. Prof. Riley recommends q judi
cious application of hot water from a
watering-rot But only careful hands
should attempt this hydropathic cure,
or the remedy NAV prove at least as bad
as the disease. The Professor also ad-
vises repeated applications of whale-oil
soap and wafer, in the proportion Of
one pound Of soap TO six gallons of wa
ter. 1t has also been suggested that a
tap may be laid for the chrysalis by
placing boards, raised two inches above
the surface Of the ground, among the
plants, to attract the caterpillars when
about to change to chrysalids. By de-
stroying these, and all that may be
found under chips, stones, etc, much
future toll and loss may be avoided.
But all these offensive and defensive
measures combined would probably be
of little avail-so impotent is man to
cope with these inferior forces!--were
it not for the diminutive allies which
come to the gardeners aid in the shape
Of minute ichneumoD flies. These lit
tie creatures lay their eggs either in
those of the butterflies or ON the out
side of the chrysalis, and the resulting
maggots feed luxuriously on their help
less victims, and do immense execution
in reducing the numbers of their in
voluntary entertainers. One observer
thinks tfat at least two-thirds OF the
chrysalids which had suspended them
selves by hundreds in the early autumn
about his house and fences, had been
attacked by these useful allies. Mr..
Charles d. Zimmerman, of Ohio, sug-
gests that these chrysalids should re
gathered into box and covered with
wire gallze, so that if they contain para
sites the latter may escape, and the
butterflies be destroyed. The box con-
tanning such chrysalids, he says, should
be protected from rain but not from
cold.
The male of this parasite-the Ptero,
MATHS p1tparum OF Linnaus- a beauti.
full pale-green fly, with the body finely
punctured and emitting metallic tints'
The antennp are honey-yellow, witt
narrow bbtck wings. The legs are pale
honey-yellow. 1t is from one-twelftf
to one-tenth OF an inch in length. The
body of the female fly is much stoutel
and broader, with an oval abdomen
ending in very short ovipositor. It il
much duller green than the male, anc
the body is more coarsely punctured
The antenna and Eggs are brown. The
larva is little white maggot about al
eighth of an inch in length. As many
as thirty-two Of thSh, in various stage
q growth, Gave been found in tn