Annual Report of New York 
562 
major) take five or six large ones to its nest in a very few minutes. Tn 
inclosed gardens, sea-gulls, with their wings cut, are of infinite ser¬ 
vice. I had one eight years, that lived entirely all the whde upon 
the insects, slugs and worms which he found in the garden. Poultry, 
of any sort, will soon clear a piece of ground.” 
But the most efficient enemies of these butterflies are their internal 
parasites. These are mostly very small ichneumon flies, resembling 
winged ants. The most common of these parasites is the Microgasier 
glomeratus. This minute fly punctures the skin of the cabbage 
worm in thirty to sixty places, inserting an egg in each puncture, 
from which a maggot hatches, which feeds internally upon the worm, 
weakening it to such an extent that it dies immediately after these 
maggots have got their growth and issued from it. 
Another important parasite is the Pteromalus puparum, which, on 
finding a pupa which has newly entered this state, places upon its 
surface her whole stock of eggs,'to the number of two or three hun¬ 
dred And the exceedingly minute maggots which hatch from these 
eggs, eat into the pupa, and there complete their growth and trans¬ 
formations in about a fortnight, the tiny flies then coming out m a 
swarm, hovering and dancing around the dead pupa until the sexes 
have paired, when the females fly away to find new pupae on which 
to place their eggs. 
Another ichneumon fly is much larger, and distributes its eggs 011 c 
to each pupa. Still, another exceedingly minute fly is reared in the 
eggs of these butterflies. 
As yet, I have met with no internal parasites infesting these larvie 
or pupae in this country. Mr. Provansher, of Quebec, however, has 
obtained a two-winged fly from one of the pupae, which resembles one 
of our common flesh flies. 
Other predaceous insects and arachnidans slay and feed upon these 
-cabbage worms, and some of these slaughter such numbers that they 
are nearly as efficient destroyers as are their parasitic enemies. “ 
the first of September, upon a plant which had nine leaves, the largest 
one6 being five or six inches broad, I counted seventy-one eggs. s 
■the plant could not sustain one-third #f this number of worms, 1 
let these eggs remain undisturbed, to observe their subsequent ns- 
tory. Five days afterward, there were on this plant twenty infant 
worms, and only thirteen eggs. Thus thirty-eight eggs, more than 
half of the previous number, had disappeared. On the under side ot 
the leaves, in several places, small holes, two or three contiguous to 
each other, were eaten into the pulp of the leaf, showing that young 
