40 SOME INSECTS INJURIOUS TO TRUCK CROPS. 
apparently all fresh, 10 were males, and 7 were large nymphs, the 
aim being to get as many of the earliest ones of the maturing brood 
as possible without introducing any belated ones of the parent brood. 
By this method it was hoped to get the succeeding brood, if there 
was to be one, as soon in the cages as it appeared in the field, and 
thus establish a minimum time between broods. 
On August 14 this cage was examined, and all leafhoppers seen 
were adults. There were no signs of egg scars or of damage. 
On August 30 but few leafhoppers could be seen, and no egg scars 
or damage. 
On September 12 the leafhoppers were almost all gone, and no eggs 
had been laid, either in the cage or field, and dissection showed 
that the females had no visible eggs in the abdomen up to date. It 
was thought at this time that the adults would lay eggs in the fall 
and then die. Accordingly a new lot was started, as shown below. 
Cages 10 and 11 (large lantern globes). — On August 30, 30 leaf- 
hoppers were introduced into No. 10, of which 12 were females. In 
No. 11 one female and several males were introduced. On September 
12 no egg scars could be found in either cage. 
Cages IS and i^-(silk scrim with a glass top). — On September 12, 
20 leafhoppers, nearly all of which were females, were placed in 
cage 13. 
On October 20 the field of beets was harvested. The cages were 
removed and the beets labeled and sent on for examination. Each 
leaf and stem, and even the parts of the beet itself protruding from 
the ground, were examined carefully, but no sign of any egg scars 
could be found on these beets or on those from the previous cages. 
Many of the leafhoppers were alive at the time the cages were re- 
moved, and there seems to be no doubt that they must hibernate as 
adults. 
SUMMARY OF LIFE HISTORY. 
By the time the beets were thinned the leafhoppers began to appear 
in the fields and by the middle of June were well distributed. They 
gradually increased in numbers for some time after this. Egg laying 
began at Lehi, Utah, late in June and continued until late in August, 
each female depositing about 80 eggs, the period of deposition ex- 
tending through several weeks, the greater number of the eggs, how- 
ever, being deposited in the ten days preceding the middle of July. 
The nymphs appeared in small numbers by July 10, and were still to 
be found in small numbers in September. A great majority of them 
emerged from the eggs the last ten days in July and changed to 
adults some twenty days later. The first adults appeared from these 
nymphs the last of July and continued to increase in number through 
August. The egg stage in the cage experiments was between thirteen 
and fifteen days; the larval stage between sixteen and twenty-two 
days. 
