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60 . ANNvaL Buporr': >is iaewte. 
coloy, pohiiel with a dense, velvety SESE and ornamented "i 
longitudinal yellow stripes. It does not, as in the case of our native s 
fine its depredations principally to the outer leaves, but has the habit 
into the heart of the plant, and defiling it through and through with its gnawings 
‘and excretions. In localities where this worm is naturalized, no cabbage can es 
committed to the pot without first being picked to pieces and each leaf eer , 
looked over to detect worms that may be lurking in its folds. 
The increase of this insect has been materially checked during the ‘sian ioe, 
or eight years, by the attacks of two parasites. The first of these, a minute 
Chalcid, was originally supposed to be its European enemy, which had by some 
fortunate accident heen introduced into this country in infested larve or chrys- 
alides, but later investigations render it more probable that the parasite is a 
native of this country, as well as of Europe, and that it probably preys upon our 
native species in the absence of the imported one. It is a very small, metallic 
green, four- wimged fly, and bears the scientific name, Pteromalus puparum, 
Linn. This fly punctures the skin, and lays its eggs on all parts of the worm, 
and the tiny maggots, often to the number of forty or fifty, feed upon the fatty 
tissues near the surface, so tnat the larva, though weakened, is not vitally injured 
by their presence, and is able to change to chrysalis. The parasites then work 
deeper, and soon destroy the life of their victim; and in the course of ten or 
twelve days the flies begin to emerge. 
The second parasite is a Tachina fly, a two winged insect about the size of the 
common house fly, which it closely resembles in general appearance, This insect 
has also proved a valuable ally of the gardener in reducing the numbers of the 
cabbage worms. 
Various applications have been experimented with in destroying the worms, 
but for the most part those that were efficacious against them, such as carbolie 
powder, white hellebore, and Paris green, at the same time rendered the plants 
upon which they were used unfit for food. Dusting with lime and wood ashes, 
and drenching with hot water, have been tried with considerable success. The 
best measures, however, are preventive and consist in trapping the chrysalides 
under pieces of board plaeed here and there among the plants, and elevated an 
inch or two from the ground by means of clods or stones under eachend. When 
ready to change the worms will eagerly avail themselves of such shelter, and the 
boards should be examined every week or ten days during the season, and the 
chrysalides removed and destroyed, with the exception of those that are parasit- 
ized, which may be known by their dark livid color. Another preventive is to 
catch the butterfles, which always fly low and slowly, in a butterfly net. The 
latter is a bag two or three feet in length, made of coarse book muslin or mos- 
quito netting, the open end being secured around a hoop of thick wire, having 
the ends twisted together and soldered into a narrow tin tube to form a handle, 
which can be lengthened at pleasure by fitting into it a stick or cane. The but- 
terflies can be caught on the wing or as they alight, by throwing the net over 
them and giving it a dextrous twirl to secure them, after which a slight pinch 
between the thumb and finger puts an end to their power for injury forever. 
The cabbage plant is liable to the attacks of a large number of other insects, 
but none of these have proved formidable pests with us, although further south 
the damage done by some of them renders the cultivation of cabbage very unsat- 
isfactory and unremunerative. 
