Garden Pests in New Zealand: A Popular Manual for Practical Gardeners, Farmers and Schools — John Stuart Mill — John Shaqi
Garden Pests in New Zealand: A Popular Manual for Practical Gardeners, Farmers and Schools
John Stuart Mill · en
The caterpillars of this insect are particularly severe in their
attacks upon the foliage of cabbages and cauliflowers, though they
also feed upon many other related plants, such as lettuce and radish,
besides cruciferous weeds. The caterpillars of the white butterfly
are not to be confused with those of the diamond-backed moth, already
described. The full-grown white butterfly caterpillar is a conspicuous
insect, and measures up to an inch and a-quarter in length; it
is easily distinguished by its leaf-green colour and velvet-like
appearance, while down the centre of the back is a narrow orange
stripe, and on each side a brownish line formed of little spots. The
chrysalis measures about three-quarters of an inch long, having a
pointed process from the head, and a keel-like ridge on its back,
while the colour varies according to the surroundings with which the
chrysalis blends; it is not protected by a cocoon of silk, and may be
found upon the food plant or any other support near by.
The butterfly itself is a very conspicuous insect, measuring about two
inches across the expanded wings. The female is of a yellowish-white
colour, with darker to blackish markings at the fore-angles of the
front wings, while there are two similar spots on the surface of the
same wings, and one on the hind pair. The male is whitish, with a dull
greyish-green or bluish hue, marked much as the female, except that
there is only a single spot on the surface of each wing.
The eggs (Fig. 10, 7b) are bottle-shaped, and stand erect upon the
leaf surface, where they are laid singly, and not in batches; they are
visible to the naked eye. The eggs hatch within a week after being
laid. There are several generations each year.
The cabbage butterfly can be controlled by the use of lead arsenate. It
has been found effective when planting out to first dip the seedlings
in lead arsenate at the rate of 1lb. in 50 gallons of water, to which
1lb. of laundry soap is added as a spreader. During the growth of the
crop the same strength of arsenate and soap can be applied as a spray.
MAGPIE MOTH(_Nyctemera annulata_).--One of the commonest and most
conspicuous day-flying insects of the garden and field is the magpie
moth. It is black in colour, relieved by an orange-banded abdomen and
whitish spots on the wings, two on each of the front wings and one on
each hind one. Its black, hairy caterpillars, commonly called “woolly
bears,” have narrow brick-red lines along the body, and very often do
some considerable damage to cinerarias; they also attack weeds, such as
ragwort and groundsel.