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leaves are joined, a silken net covering the top. The designer of this 
arrangement is a small caterpillar. The roil, bud or space in the 
leaves serving the double purpose of place of concealment from ene¬ 
mies and also that of furnishing food. The choice of thus forming 
the house depends both upon the texture of the leaf and the insect’s fu¬ 
ture requirement—whether to be inhabited singly or in numbers. Lin¬ 
naeus, an eminent Swedish naturalist, gave the name Tortricidse to 
those insects possessing this habit, the word Tortricidx itself being 
derived from a Latin word signifying to curl or twist. 
All the caterpillars placed in this family by the present naturalists 
are not, strictly speaking, leaf-rollers, since some are found under the 
bark of trees or on roots of young plants, while still others are found 
living exposed on plants. 
The insects embraced in this family are not considered very injuri¬ 
ous, since, as a rule, they do not occur in any considerable numbers, 
but like all others are subject to variations, and some seasons numbers 
appear in different localities, and cause much damage. 
The moths belonging to the Tortricidse are of a small size, rarely 
expanding over an inch. The fore wings broad and variegated with 
bands and spots, often brilliant metalic hues, while the hind wings 
are dull colored like the body, the inner edge being folded fan-like 
against the body. The palpi are short, and the antennae filiform. 
They fly mostly at night, and are found during the day upon the 
plant on which the larva feeds. 
The larvae are cylindrical, usually transversely wrinkled, and nearly 
naked; when disturbed they drop suddenly, suspended by a fine silken 
thread. 
To this family the moth under consideration, Argyrolepia guercifol- 
iana, Fitch, belongs. It was first observed by Dr. Asa Fitch, and 
described b;y him in his 4th New York report in 1858, since which 
time nothing has been written in reference to it until an article by 
myself, printed in the Prairie Farmer , August, 1877. During 
the past four years it has been observed in Northern Illinois, but not 
until the summer of ’77, did it occur in any alarming numbers. 
Through the kindness of E. R. Boardman, Elmira, Stark Co., F. M. 
Webster, Waterman, De Kalb Co., and C. H. Davis, Le Roy, McLean 
Co., I have been enabled to trace the habits of the insect through 
its various stages. 
The kinds of oak in the forest mostly injured are the Black Oak, 
Quercus tinctoria , red Oak, Q. rubra, burr oak, Q. macrocarpa, and white 
oak, Q. alba ; Mr. Riley informs me he has met the insect quite com¬ 
mon around St Louis in Spring on the pin oak, Q. palustria, and I 
also understand through Mr. Graves, that it has occurred in Kendall 
county during the past summer. 
Natural History. —The insect appears with us the middle of May, 
and at first eats only the parenchyma of the leaf, leaving the veins, 
and turns over one end of the leaf, leaving the ends open ; in this home 
the caterpillar finds its food and place of retreat. 
When full grown, which with us is about the first of June, the 
worm changes into the chrysalis, first spinning a silken bed upon the 
leaf and then remaining inside the leaf during the chrysalis state. 
