February, ’18] 
WEBSTER: STRAWBERRY LEAF-ROLLER 
43 
strawberry foliage. A second generation appears late in June, and 
this is likely to last well through the month of July. 
Again in August a third generation appears. This may be followed, 
in some years, by still another generation in September, making four 
generations. Our observations indicate that the fourth generation is 
not always complete and that, in some years at least, third generation 
larvae spend the winter in strawberry foliage. 
The most important facts from the study of the life-history are 
those bearing on the practical treatment. To be effective, spraying 
must be done early in the game, that is, before the larvae have folded 
or rolled the leaves. After the leaf-rollers begin feeding and rolling 
leaves any treatment by spraying is largely ineffective. 
The first chance for effective spraying is early in May. Arsenical 
spraying for strawberries, however, should be made previous to blos¬ 
soming, since spraying while plants are in blossom would probably 
poison bees. Spraying at this time, that is, about the time the eggs 
are deposited, is essential to place the poison on foliage before the 
eggs hatch. 
The Egg: Description 
J. M. Stedman (1901) seems to have been the first one to observe 
the eggs and these were described by him, although no measurements 
were given. J. B. Smith (1909) also described the eggs and C. A. 
Hart (1911), working over notes made by J. J. Davis and the writer 
in Illinois in 1905 and 1906, gave a description and measurements. 
The egg: Oval, varying greatly, much flattened: pale yellow-green, 
translucent. Surface pitted with numerous slight hexagonal depres¬ 
sions. Length .68 mm. Width .48 mm. (Average of 10 specimens 
deposited on foliage.) 
Eggs deposited on the glass in insectary cages were quite uniform in 
shape; a true oval. The surface of the strawberry leaf with its fine 
hairs influences the shape of the egg on a leaf. 
Place of Deposition 
Stedman, Hart and J. B. Smith all state that the eggs are deposited 
on the under sides of the leaves. J. B. Smith stated that he had never 
seen an egg on the upper surface. 
In field observations eggs were found placed on either surface and 
even on the stems. In the insectary cages, eggs were usually deposited 
on the upper leaf surface but frequently were placed on the inner sur¬ 
face of the glass chimney in which moths were confined. Field obser¬ 
vations, in which counts were not made, indicate that on the whole the 
lower surface was preferred. The highest number of eggs found on a 
single strawberry leaf in the field was five. 
