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: Minnesora Svare HorricuLtTvuraL. Sociery. 59 
season, the second brood, like that of protodice, being the most destructive. , The 
development of this insect is somewhat irregular, and it may usually be found in 
all its stages during the months of July and August and the early part of Sep- 
tember. The larve of both these native species feed preferably upon cabbage, 
but also devour with apparent relish the leaves of turnip, cauliflower and kohl- 
rabi, and are occasionally found upon radishes, cress, pepper-grass, mustard and 
y several wild plants of the same family (Cruciferae). 
The first named species feeds indiscriminately on the upper and under sides of 
the leaves, and is easily detected by its dark and variegated coloring. The sec- 
ond species, on the contrary, conceals itself on the under side of the outer leaves, 
with which its green color so closely blends that it requires careful search to 
discover it. 
Destructive as these indigenous butterfly larve sometimes prove, their depre- 
dations are trifling in comparison with those of the imported Rape Butterfly (Pie- 
ris rape, Schrank). This insect has long been known throughout Europe as 
one of the most serious pests of the vegetable garden. It was introduced into 
this country about twenty years ago, and has since spread over almost the entire 
Dominion of Canada, and established itself throughout the northern and middle 
Atlantic states. It was first recognized in the vicinity of Quebec, to which port it 
was doubtless unconsciously brought and cast ashore in the egg or chrysalis state, 
with the refuse from some vessel; or perhaps the butterflies from chrysalides 
suspended during the voyage, escaped while the vessel was at the dock, and 
fluttered landward to perpetuate their kind on new soil. As with most imported 
insects, the change of climate seemed to impart new vigor to this pest, and as its 
European parasites had not followed it across the ocean, and our native species 
had not then adapted themselves to the immigrant, it multiplied for the first ten 
years with exceeding rapidity, and in 1870 was estamated to have destroyed, in 
the neighborhood of Quebec alone, more than $240,000 worth of cabbages. Its 
ravages were equally severe for some years in the market gardens around Boston, 
New York, Philadelphia and other eastern cities, where the unconscious gar- 
dener would walk amid a snow storm of white butterflies, bemoaning his ragged 
and wilted rows of cabbages and cauliflower, without dreaming of associating the 
innocent looking flutterers around his head with the work of devastation gomg 
on at his feet. To illustrate how little general knowledge there is upon the sub- 
ject of the transformation of insects, it is said that a certain entomologist while 
attempting to capture some of the butterflies from one of these suburban gardens, 
was driven out with much abuse by the irate gardener, for beating down the 
plants with his net. -In vain the gentleman attempted to explain the service he 
was rendering in the capture of the butterflies. He was listened to with absolute 
incredulity. The gardner could never be made to believe—not he—‘‘that catch- 
ing white butterflies in a bag would save cabbages from worms ”’! 
As this destructive insect is slowly but surely advancing westward, it is well 
for us to make ourselves acquainted with its characteristics in order that we may 
recognize it upon its first appearance, and yield it ‘‘ no quarter.”’ 
The two sexes of the imported butterfly are much alike, and bear a casual 
resemblance to the male of the so-called Southern Cabbage Butterfly. The body 
and the tips of the front wings are black. ‘The female has two conspicuous black 
spots near the outer edges of each of the front wings, while the hind wings are 
marked with a large spot on the upper edge and a smaller one near the middle. 
The male has a single biack spot on each of the front wings and an indistinct 
one on the upper edge of each of the hind wings. The larva is of a deep green 
