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THE SPRING GEAIX-APHIS OB 
bodies of the viviparous individuals, so long as warm weather con- 
tinues or until the females become old and die a natural death. The 
viviparous forms appear to be as susceptible to extreme cold as are 
the oviparous individuals. 
From the 14 experiments that were conducted to determine the 
period of oviposdtioii it was found that it varied from 3 to about 25 
days. If. after becoming adult, the female be kept for a week or more 
and then placed with the male it appears that the reproductive period 
is shortened. 
Fig. 16. — The spring grain-aphis: Aberrant female with eggs and embryos in abdomen, showing through 
the body wall. Enlarged. (Original.) 
LENGTH OF LIFE OF THE SEXES. 
The males reach maturity, it seems, as quickly as the oviparous 
females, but their lives are much shorter. The males live from 8 to 10 
clays after becoming adult. 
The length of life of the oviparous females depends principally 
upon two factors, namely, weather conditions and the presence of the 
male. Under favorable weather conditions, and in the presence of the 
male, they will live from 31 to 6S days. If the male is not present 
they will sometimes live as long as 88 days. Under these circum- 
stances they rarely deposit eggs, only one instance, as previously cited, 
having come under our observation where they did oviposit and then 
the eggs were not fertile. Their abdomens become greatly distended 
with eggs, and upon being dissected, as many as six or more full-sized 
eggs may be found. 
