1926] Notes on the Behavior of Dineutes americanus 157 
the surface, but swam about on the bottom of the dish showing 
great energy and no loss of faculties during the minute it was in 
the liquid. On being removed to the surface of water it at once 
overturned and swam about belly-upward. When righted it 
swam deeply, keeping the head under water. It was then placed 
on a raft from which it dragged off with some difficulty and re- 
mained quietly on the water. The legs were not apparently 
capable of successful movement and at the end of five minutes 
the body was relaxed and the beetle died without any indication 
of activity. The experiment was repeated with weaker solutions 
as shown in the table. With the denser liquids, the ability t° 
keep afloat was perceptibly greater but in no case was it entirely 
satisfactory due to the decrease in surface tension. 
% Alcohol 
Length of Life 
% of time submerged 
during one minute 
50 
5 minutes 
total 
25 
2 “ 
total 
10 
30 “ 
97 
5 
60 “ 
92 
4 
undetermined 
89 
The lighter specific gravity of the medium in combination 
with the fact that the alcohol serves to wet parts of the body 
that are normally dry causes the difficulty in keeping afloat. As 
these insects are easily drowned, death was probably from that 
cause rather than from alcoholic poisoning. 
A salt solution of the density of seawater (1.026) was also 
used. There was no apparent t ouble in swimming but the 
diving speed was very much slowed down. The beetle did not 
object to the solution but finally crawled up the dish and es- 
caped to the table. 
During the fall of 1924 and the spring of 1925 a close watch 
was kept on several ponds in the vicinity for indications of the 
winter habits of this insect. One pond was especially scrutinized 
because of its greater population during the summer months. 
