22 BULLETIN 19, U. S. DEPARTMENT OE AGRICULTURE. 
were placed on the foliage of a young Concord grapevine on July 12. 
On July 13 several of these nymphs had transformed to adults. On 
July 16 about 75 per cent of them had developed wings. 
MATING OF FIRST-BROOD ADULTS. 
On July 22 numerous pairs of adults of the new brood were found 
copulating on the underside of grape leaves in the vineyards sur- 
rounding North East. Pa. From July 23 to 27 copulating pairs of 
new-brood adults were common, both in the vineyards and in cages 
at the laboratory. After the latter date only occasional mating 
pairs of adults were observed, either in the rearing cages at the 
laboratory or in the open vineyards, although observations along 
this line were continued during the remainder of the active season. 
NUMBER OF EGGS DEPOSITED BY A FEMALE OF THE FIRST BROOD. 
On July 26 three copulating pairs of the new-brood adults were 
placed in separate cages on a Concord grapevine inclosed in an arc-light 
globe cage similar to those in which pairs of overwintering adults had 
been confined, the object being to ascertain the number of nymphs 
that could be reared from them in order to see how it compared with 
the number produced by overwintering females. The number of 
nymphs reared from these first-brood females is shown in Table VI. 
Table VI. — Number of nymphs produced by a female leqfhopper of the first brood. 
CAGE INTO. I. 
Xvmphs 
Date examined (1912). removed. 
Sept. 4 12 
Sept. 7 5 
Sept. 11 7 
Sept. 14 9 
T. »tal 33 
cage >:o. rr. 
Sept. 3 24 
Sept. 5 J 16 
Sept. 9 17 
Sept. 11 . . '. . . 9 
Sept .15 .' 13 
T( ital 79 
CAGE X<>. in. 
Sept. 4 37 
Sept. 7 : 35 
Sept. 11 9 
Total 81 
In the case of these three females of the first brood, the average 
number of nymphs produced by a single female was only a little more 
than half the number produced by the overwintering females under 
similar conditions. 
