159 
reported by an excellent observer (Dr. E. II. Boardman) to 
have occurred one season in southeastern Iowa as early as 
June 25, some larvae must hatch by the beginning* of that 
month. Pupation can scarcely begin later than June 20 if Dr. 
Boardman’s date for the beetle is correct, and the same ob¬ 
server reports the finding of the pupa itself in the earth June 
29. On the other hand, larvae ready for pupation have oc¬ 
curred in our collections as late as August 26—giving a period 
of something over two months for the pupation of an entire 
generation. 
The extreme dates definitely fixed for the next transforma¬ 
tion—the emergence of the beetle—are June 25 for the earliest* 
and not earlier than August 31 for the last—again a period of 
something more than two months. We have seen the beetles 
copulating at various dates from July 19 to September 25,— 
an interval of two months and six days,—observations which 
probably fix approximately the beginning and the end of ovipo- 
sition. The eggs, however, were not all laid by October 1, 1882, 
as I determined by dissecting females at the time. For the 
present we may assign August 1 and October 5 as the average 
dates for the first and last deposit of eggs. 
The recognition of this eight or nine weeks’ period for the 
passage of the whole of a brood from one stage to another, 
enables us to say with some assurance that the eggs laid during 
this long interval in one }mar will hatch through a correspond¬ 
ing interval the year following—approximately from May 15 to 
July 15, or a little later. While these dates are, some of them, 
inferred, there is no doubt of the extension of each stage of the 
development over as long a period as that here given; namely, 
two months to nine weeks. We have no precise observations 
concerning the length of life of any individual in any one stage; 
neither do we know the number of eggs laid by each female, 
except as an inference from dissections. I have counted as many 
as fifty well-formed eggs of nearly full size in the ovaries of a 
single female beetle. 
HABITS OF BEETLE AND LABVA. 
The growinglarvae remain concealed from view within the roots, 
burrowing, not through the middle but nearer the surface, in a 
slightly sinuous longitudinal direction, sometimes from the stalk 
outwards, but more frequently mining inwards from the outer 
end of the root. They have considerable power of locomotion 
when removed from their burrows, and seem capable of going 
from one root to another. Indeed, the fact that they must con¬ 
centrate in hills of corn after hatching, demonstrates their power 
of locomotion when still very young.t It is altogether likely, 
* On Dr. Boardman’s authority. 
+ Although their thoracic legs are very short, they are nevertheless functional, and the 
hinder end of tho body is provided with a kind of anal proleg, which serves as an aid to 
locomotion. 
