The ranch. [volume] (Seattle, Wash.) 1902-1914, 1905-06-15
THE FIELD
The Imported Cabbage Worm.

enemies of the cabbage and other cru
offers is the larva or caterpillar of a
white butterfly known to science as
Pontia rapae Linn. The caterpillar,
called the imported cabbage worm, is
altogether too well known by farmers
throughout this country as well as in
the old world, and the adult insect, the
imported cabbage butterfly, Called
also the white or rape butterfly, is
a familiar object to nearly every one.
1t is generally recognized that the but
terfiy is the parent of the caterpillar.
This cabbage worm is velvety green in
color, much like the cabbage on which
it feeds. There is a faint yellow stripe
down the middle of the back and a
row of yellow spots along each side
with the spiracleS or breathing pores.
1t measures, when full grown, about an
inch and a fourth. The butterfly has
wing eXpanse of nearly two inches,
and is white, marked with black near
the tips of the fore wings. In the fe-
male there are two conspicuous black
spots on each fore wing, while the
male has only one. Both sexes have a
corresponding smaller black spot at
the upper extremity of the hind wings.
The body of the female is whitish, and
that of the male is usually darker
above. The male is generally little
the smaller. The under surface of the
hind wings is uniform satinw straw
yellow and there are generally two
black spots showing through, in both
sexes.
The eggs are fusiform, pale yellow
ish, and strongly ribbed. They are
large enough to be readily seen with
the unaided eye and are deposited
singly, usually on the lower surface
of the outer leaves of cabbage and
other plants When the caterpillar
or worm becomes full grown it at
taches itself to cabbage leaf or other
nearby object, fastens itself by means
of stringlike girdle, and often within
the same day transforms to chrys-
allis, which is of variable color, seem
ing to be influenced in this respect by
the object upon which it is placed.
The color thus varies from dirty gray
to yellow, green, and dark gray. The
length of the chrysallis is a little less
than three-fourths of an inch.
This cabbage worm begins work
early in the season, and the principal
damage is therefore usually to young
plants. After Kidding the outer leaves,
winch commune dIIoTWdru dIIdCuou W
the stalk, it attacks the more tender
inner leaves as they form, frequently
secreting itself in the heads, which are
made most unsightly by it's dark green
excrement, and there it is difficult to
reach it with insecticides. AS rule,
cabbages before being sent to market
must be carefully examined and the
damaged leaves plucked away; and
before cooking it is frequently neces-
sary to tear the heads apart to see
that no disgusting worm" is lurking
within. In cool weather the cater
pillar frequently feeds in free exposure
on the upper surface of the leaves in
the sunshine.
The imported cabbage worm, So
called from the fact that it was intro
duced from Europe into Canada and
finally into the United States some
fifty years or more ago, feeds on the
foliage of nearly all cruciferOus plants,
is particularly fond of cabbage and
cauliflower, and somewhat less dest1tuc-
tive to turnip, radish, mustard and
horseradish. 1t also does considerable
injury to ornamental plants, such as
the nasturtium, mfgnonette. sweet
alyssum, spider plant, etc. The but
terflies sip the nectar of flowers of
II. 4 h. of n