89 
inconspicuous, on the lower surface of the leaves, usually along the 
principal \eins. Young leaves, which have many fine hairs on the 
under surface, are freest from them. 
The newly hatched larva is not more than 1.25 mm. long. It 
feeds at first exposed, mostly on the under surface, gnawing the 
epidermis as do most young caterpillars, and not cutting thru the 
leaf. A few days later it begins to make a web and roll up the leaf, 
eating holes entirely thru it. The hibernating larvae were first 
seen to feed April 21, only a few days before pupation. 
The pupa is invariably formed within the rolled leaf. 
The adults copulate soon after emergence. Copulation has been 
observed on three different occasions, in all cases between 8 130 and 
9:30 p. m. Egg-laying begins within two or three days after 
emergence. 
The two remedies most frequently recommended are burning 
over the fields after harvest, and spraying the plants with some 
arsenical poison in spring when the larv?e are hatching, and before 
they have rolled the leaves to any extent. The latter period comes 
so soon before the ripening of the first fruit that some other plan is 
very desirable. It is a common practice to consider infested fields 
as worthless and to destroy them by plowing after harvest. Mr. 
Fred Hubbard, an enterprising strawberry grower of Urbana, con- 
ceived the idea of spraying his fields after harvest, and representa- 
tives of this office have investigated the results. The spray used 
was arsenate of lead, i^ pounds of lead acetate and 11 ounces of 
arsenate of soda to 100 gallons of water. The field was sprayed 
once a week from the close of the harvest until frost. Four rows in 
the middle of the field were left as checks. A thoro examina- 
tion of the field after the close of the spraying gave the most posi- 
tive evidence of its good effect. The unsprayed rows could readily 
be picked out. The sprayed plants had more foliage, and it was 
all of a healthy rich green color, while the foliage of the unsprayed 
rows was discolored and less abundant. The larv?e were very com- 
mon on the unsprayed rows and entirely absent from the sprayed 
rows. 
The effect of this treatment upon the crops of the succeeding 
season was marred by two facts : first, the reinfestation of the 
sprayed rows from the adjoining unsprayed ones left as checks ; 
second, the general reduction of numbers among the leaf-rollers 
due to natural causes. Strawberry fields everywhere, regardless of 
treatment, were comparatively free from them that season and a 
good crop of fruit was secured. If the entire field had been sprayed 
there is every reason to suppose that even under the most favorable 
^conditions for leaf-rollers the field would not have again become 
infested the following spring, and that no damage to the crop from 
this cause would have occurred. 
