406 
JOURNAL OF ECONOMIC ENTOMOLOGY 
[Vol. 13 
The first cage record of eggs of the summer generation adults was on 
July 11. Under field conditions hatching had become general July 23, 
showing that the above date was probably correct. Field counts also 
showed that the period of greatest egg deposition extended between 
August 6 and 24. A few nymphs were still hatching from the vines as 
late as October 3, so it is probable that oviposition of the summer 
generation extended throughout September, since these nymphs could 
not have been from second brood adults, as shown later. The average 
number laid a day was practically the same as with the overwintered 
generation, one fertile egg a day being the general rule under cage 
conditions. 
Attempts to Rear a Third Generation 
Attempts were made to get second generation females to oviposit 
but without success. All adults in this experiment were obtained by 
rearing nymphs that were known to belong to the fall generation. 
Owing to the nature of the cages used the mortality was high in this 
experiment. Second brood females, however, also failed to lay eggs 
in the large lantern globe cages used as checks. In these cages a much 
larger percentage of hoppers lived and were alive when last examined, 
November 8. This generation thus passes the winter without becom¬ 
ing sexually mature. They appear again, as stated, late in May and 
feed promiscuously for a week or so before the spring flight and oviposi¬ 
tion take place. 
Incubation Period 
Under field conditions the incubation period extended from ten to 
fifteen days, with an average of fourteen. In the insectary, wheie the 
temperature averaged nine degrees higher than outside, the egg stage 
lasted from four to ten days for the first generation and four to twelve 
days for the second. An average of about seven days was noted for 
both broods under these conditions. 
Table II. Incubation Period in the Field 
Eggs laid 
Average date 
hatched 
Average incubation 
period 
Average incubation 
for broods 
J une 3. 
June 17 
14 days 
first, 13 days 
July 12. 
July 23 
11 “ 
July 14. 
July 26 
12 “ 
Aug. 2. 
Aug. 12 
10 “ 
second, 11 days 
Aug. 15. 
Aug. 27 
12 “ 
Aug. 29. 
Sept. 8 
10 “ 
