474 
ANNUAL REPORT OE NEW-VORK 
of apple trees. But they are seldom noticed, as they are not 
numerous and do not cluster together in societies, but occur soli¬ 
tary and sparsely scattered among the leaves. One of the most 
common of these, every year, is a pale green worm of nearly the 
same hue as the under surface of the leaves, and having numer¬ 
ous pale or white dots and five whitish lines running lengthwise 
of its body. On beating the leaves of apple trees some of these 
worms almost always fall into the net. They begin to appear 
the last of May, and are then small and of a more bright lively 
green color than when they are full grown. They live openly 
exposed on the under sides of the leaves, without forming any 
web or fold in the leaf for their concealment and protection. 
Though they are more common upon the apple than elsewhere 
they are not limited to this tree, but occur also on the cherry, 
the peach, and upon elm, poplar and other forest trees. They 
reach maturity about the last of June, and then measure an inch 
and a quarter in length, and 0.20 in diameter. The worm then 
selects an entire, thrifty leaf and contrives to bend one half of 
it into a convex form by attaching a fine silken thread which it 
spins from its mouth, first to the outer edge of the leaf and then 
to or beyond the middle vein, drawing each successive thread 
tight, as it fastens its end. It thus gradually curves the leaf until 
it forms a hollow or cavity of sufficient depth to receive its body 
under the threads. It then crawls into this cavity and continues 
to spin its threads, crossing them in every direction, until it has 
wholly shut itself in beneath the paper-like tissue which, it 
wea ves. Thus whilst many insects are put to the labor of spin¬ 
ning a ball or a pod-like cocoon for their protection during their 
pupa state, this worm has the artifice of bending a leaf so that 
it forms nearly two thirds of its cocoon, thus greatly abridging 
the amount of work to be done at this period of its life. Within 
the cavity thus formed it changes to a chrysalis, from which the 
perfect insect, which is an ash-gray moth or miller with a lew 
slender black lines marking its fore wings, is subsequently 
hatched. One of the worms which shut itself within its cocoon 
on the twenty-fifth of June gave out the moth on the twenty-fifth 
of July. But I have captured the moths as early as the begin- 
ping of July, and worms which have not enclosed themselves in 
