River Falls journal. [volume] (River Falls, Pierce County, Wis.) 1872-2019, 1905-07-20

a, female butterfly; b. above, egg as
seen from above; below, egg as seen
from side; c. larva in natural position
on cabbage leaf; d, suspended chrysalis
"a, C, d, slightly enlarged; b. more en-
larged (originaD.
to temperature. The observed egg Pc
Rod is from four to eight days.
The larva eats voraciously and
grows with great rapidity, attaining
full maturity in from ten days to two
weeks after Matching. 1t molts four
times; hence there are five distinct
stages, the first mott taking place Gin
warm weather. in about two days
from the hour of Matching, the second
stage lasting two or three days; the
third and fourth, one or two days each,
and the fifth, four or five days. The
duration of the chrysalis stage is from
seven days to a fortnight during the
summer time, but the last chrysalides
formed in the more northern states
remain undeveloped during the win
ter until the following spring.
The life cycle occupies periods vary
ing between % days and five weeks.
Even in New England this species is
credited with being triple-broode1,
but in the District of Columbia aad
vicinity there must be one or more
additional generations, and there is a
possibility of at least six in the ex-
treme south. The first generation de-
velops on wild plants.
In the treatment of this species it
should be kept in mind that other
worms" and other cabbage pests are
more often present than not.
Arsenicals-The best remedy is one
of the arsenicals; and paris green
and arsenate of lead are preferred to
others in common use. II the former
is used it may be applied either dry
or wet, preferably, however, as spray,
at the rate Of about one pound OF the
poison to 150 gallons of water 1t
should be applied when the plants are
first set out, so as to insure the poi
son reaching the young larvae before
they have burrowed far into the
heads. Other applications should fol-
low as required. These can be made
with absolute safety until the heads
matter, even later, as the poison dis
appears from plants almost complete
" within three or four weeks after
application.
Bran Mash.-A mixture of bran with
paris green, one of the standard rem
edies for cutworms as well as grass
hoppers, is, according to the testimony
of some who have used 1t, successful
against cabbage worms" and should
be tried against the present species.
Any arsenical can be employed in the
preparation of this mixture. 1t is best
to mix the brand with water and
sugar before adding the poison. The
proportions are two or three ounces
of sugar or other sweetening, and
about one pound of bran, to a gallon
of water; so as to make, when stirred,
a mixture that will easily run through
the fingers. In its application it is
merely sprinkled, either wet or dry,
over the affected plants.
Hand Picking.-For the kitchen gar
den where, for obvious reasons, it is
undesirable to use arsenicals, hand
picking is sometimes practiced, espe-
cially when plants are first set out.
The Cornmeal Notwithstanding
to Prof. l.. Bruner, cornmeal busted on
cabbage causes the worms" to drop
of, and protects the crop until the
meal is washed away by rain. 1t is
applied in the morning while the dew
is on and is said to act as deterrent.
Kerosene emulsion is not as effective
as the arsenicals, because in its appil-
cation it is necessary for the spray
to come into direct contact with the
larvae in order to kill them.
Henebore will kill this worm" but
is not as satisfactory a remedy as the
arsenicals.-F. H. Chittenden, OF Unit
ed States Department of As1'icultnra-