LIFE HISTORY AND CONTROL OF HOP FLEA-BEETLE. 43 
tions are about equal. In order to obtain the entire life cycle, the 
6 days' interim between the emergence of the beetles as adults and 
copulation, and also the 6 days required for the eggs to mature, must 
be added to the 72 days which are passed in the egg, larval, and pupal 
stages. In adding these, we have 84 days, or 12 weeks, as the length 
of the life cycle. 
NUMBER AND TIME OF APPEARANCE OF BROODS. 
There are two distinct broods of beetles in the Chilliwack and 
Agassiz valleys. One emerges in the ear^y spring and the other in 
the latter part of July or the first part of August. 
The first generation appeared very suddenly and in large numbers 
between April 25 and May 10. The appearance and devastation in 
the Agassiz yard was particularly startling. On April 24 the vines 
in this yard were almost ready to train onto the string and were only 
slightly damaged by the beetles. April 28 this yard was literally 
alive with the " fleas," in some places there being as many as 50 or 
60 to the vine. The leaves were entirely eaten away and many of 
the terminal buds were killed. Although this did not ruin the shoot, 
it caused a very undesirable branching. Beetles continued to emerge 
at Chilliwack in large numbers until about May 10, after which only 
a few belated individuals came out. 
The first and second generations are very distinct. The first brood 
was in its maximum numbers about the 1st of June, but after this 
the insects gradually diminished and had entirely disappeared by 
July 20. The second generation began to emerge about the 25th of 
that month, but were not present in large numbers until about 
August 10. These beetles live through the fall and winter, emerge 
in the spring, and deposit the eggs which produce the first generation 
of the next season. 
MULTIPLICATION . 
According to observations made upon the number of eggs and rate 
of egg laying, the maximum number of individuals coming from a 
single pair in the first generation would be 18. If all of these sur- 
vived and produced the maximum number again, the second gen- 
eration would amount to 162 beetles. The average number of eggs 
laid may be below 18, and a large number of larvae are destroyed by 
predaceous enemies in the soil, so that the few beetles which winter 
over will not necessarily produce an overwhelming number in the 
second generation. 
HIBERNATION. 
ENTRANCE INTO HIBERNATION. 
When cool weather comes in the fall the beetles begin to hibernate. 
They do not travel far from where they chance to be, but enter the 
