HAWK-MOTHS. 45 
coons are frequently mistaken by those not well posted iu 
such matters for the eggs of the caterpillars themselves. Of 
course this is a mistake, as caterpillars are not in the habit 
of laying eggs. Ifthe poor victim of these parasites, which 
can no longer take any food, is kept ina glass, weshall soon 
see what will become of those reputed 
eggs. Before very long we shall see that a 
px very minute wasp (Fig. 47) pushes open a 
little lid, which it had previously cut with 
its jaws, and flies off, happy to be liberated 
from its narrow cell. As all caterpillars 
attacked by these parasites succumb in the end, and never 
transform to pupa, it is well to recollect that worms carry- 
ing such egg-like cocoons should be left alone, and should by 
no means be destroyed. The small wasps issuing from 
these cocoons have nothing else to do but tosearch for other 
caterpillars in which to deposit their eggs, hence they are 
employed in very good work. 
Fig 47.—Parasite. 
THE PLUM-TREE SPHINX. 
(Sphinx drupiferarum S. & A.). 
Like all the members of the Sphinx moths, the above in- 
sect possesses a robust body, and long and narrow wings 
moved by powerful muscles, which enable it to fly rapidly 
over long distances. This accounts for the fact that they 
are found frequently at electric lights many miles away from 
their place of birth. 
The Plum-tree Sphinx (Fig. 48, Plate VI) is a handsome 
insect, but quite different from those described before, as it 
lacks their bright colors. The moth, which appears during 
June, has an expanse of wings measuring from three and a 
half to four inches. The wings are of purplish-brown color; 
the fore-wings have a stripe of white on their anterior edge, 
and one of a fawn-color on their outer one; there are also 
