58 
HALF HOURS WITH INSECTS. [Packard. 
fact that it inhabited the pupae, or chrysalides, of butterflies. 
This insect has been known to inhabit this country since 
1844, as there are specimens in the British Museum taken in 
Hudson’s Bay Territory in that year ; so that it is probably 
indigenous to both countries, while its present host in North 
America is the imported cabbage butterfly introduced in 
1857. 
I have found that another parasite attacks this insect, as 
the larva of a species of Tachina (Fig. 45) occurred :n the 
body of a caterpillar. Doubtless others will eventually be 
found to take up their abode in the body of this insect. It 
would be interesting to learn whether the birds prey upon 
the butterfly or caterpillar, and whether they assist in reduc¬ 
ing the number of these pests. We can but 
hope that the present enormous numbers of 
these worms will, as soon as the insect becomes 
fully domesticated, be held in check by the 
united efforts of gardeners and the natural erie- 
mies of the insect. 
As the worm eats the interior of the cabbage 
_ .. , or cauliflower it is difficult to deal with. Some- 
Tachma larva. 
thing can be done by showering the heads with 
a solution of carbolic acid or strong soap suds, but it is 
better to employ hand picking, and when the plants are 
hopelessly infested to throw them on a hot fire. If fed to 
animals the worms will manage somehow to escape. 
The Cabbage Web-moth .—Another destructive insect, which 
is almost cosmopolitan in its distribution, is a little green 
caterpillar, w r hich at times so abounds on the outer leaves as 
to threaten the destruction of whole fields of cabbages. It 
is most abundant in a w r arm and unusually dry season. Dr. 
Fitch was the first to observe it in Illinois during the year 
1855. lie named it Cerostoma brassicella , but it is un¬ 
doubtedly the well known European Plutella xylostella , and 
first .described by Linnaeus. Though the insect has been 
26 
Fig. 45. 
