STATE AGRICULTURAL SOCIETY. 
795 
TOBACCO-WORM. HAS A 8BC0ND PARASITE. REMEDIES. 
And after these flies have left their cocoons, it is readily told by the 
appearance of each cocoon whether it is a Microgaster or a Pteromalus 
fly which has come out from it. The Microgaster, by which all the cocoons 
are constructed, makes an opening for its escape, in a more neat and 
artistic manner than does its destroyer. When it passes from its pupa 
state and awakes to life in its perfect form, it finds itself closely pent up 
within its narrow cell —so closely that about the only motion it is able to 
make is to turn its head from side to side. And it discovers that by grasp¬ 
ing with its jaws the wall of its cell, it is hereby able to gradually roll 
itself over in its bed. And now, with the minute sharp teeth at the ends 
of its jaws, it cuts a slit transversely through the wall of its cell, length¬ 
ening this slit more and more as it gradually turns itself around, llius it 
cuts the end of its cocoon smoothly off in the form of a little lid, a few 
unsevered fibres being left on one side, which serve as a hinge to hold 
this lid in its place. The inclosed fly then pressing its head against this 
lid raises it up and crawls forth from its prison, Thus the evacuated 
cocoon has its end smoothly cut off, with the severed portion usually 
adhering to it. The Pteromalus fly, on the other hand, being a size smaller, 
is able to move about and can probably turn itself around inside of the 
cocoon. And to make its escape, it gnaws a hole through the side near 
one end, of sufficient size for its body to pass through, this hole in different 
instances being round, oval, or irregular, and its edges ragged and uneven. 
In addition to the eggs of the Microgaster, which are inserted under the 
skin of the Tobacco-worm and thus are not visible externally, I have 
occasionally met with a worm having one or more eggs glued upon its 
surface, usually placed in a crease of the skin to render the attachment 
to it more secure. These eggs are about three-hundredths of an inch loug 
and a third as thick, oval, white, smooth and glossy like enamel. Within 
them a minute soft white worm or maggot becomes formed, which is 
hatched by gnawing through the shell ol the egg at one end, and as it is 
coming out, it sinks itself downward through the skin of the worm and into 
its body, a blackish dot upon the skin near the end of the empty egg 
marking the point where it has entered. Its history I have not been able 
to trace further than this. The facts show it to be another parasite 
destroying the Tobacco-worm, and that it is probably a two-winged fly 
belonging to the order Diptera. 
The remedies for this insect arc remaining to be spoken of. But as wc 
have had no personal experience in combatting it, it will not be expected 
that we dwell upon this branch of the subject at any length. 
The leaves of the potato and tomato being of no value, the presence of 
this worm upon them is wholly disregarded, as its limited numbers never 
consume the foliage to such an extent as to perceptibly diminish the growth 
of the tubers in the one or of the fruit in the other of these plants. But 
with the tobacco it is very different. The whole value of this plant depends 
upon its leaves; consequently every morsel which this worm consumes from 
them is a loss, and if the leaves are much eaten the loss is great. The 
utmost vigilance is therefore required to save the tobacco from injury from 
