8 
Psyche 
[February 
DEATH FEIGNING IN AN AX JUNIUS AND AESCHNA 
SP. 
By C. E. Abbott, 
Elgin, Illinois. 
In reviewing the literature on death feigning of insects, I 
was unable to find anything relating to this peculiar behavior in 
dragon-fly larvae. The Severins have worked with two species of 
water-bugs, but this, and the work of Holmes on another aquatic 
Hemipteron, Ranatra, are the only references available on this 
phenomenon in aquatic insects. The theory of Holmes concern- 
ing the death feigning of insects is an interesting one. He regards 
it as an overdeveloped thigmotaxis. 
The idea of working with Anax and Aeschna readily sug- 
gested itself because of the ease with which these insects were 
obtained and the fact that work was being done with them in 
quite another group of experiments. It was observed that, when 
the animals were taken from the water and placed on a solid 
object, they remained motionless, with the cloacal valves closed, 
and their legs pressed closely against their sides. To put the 
INDIVIDUAL TESTS 
Individuals 
Trials 
I 
II 
Ill 
IV 
V 
VI 
VII 
1 . 
1 min. 
30 sec. 
1 min. 
45 sec. 
no 
response 
2 min. 
30 sec. 
9 min. 
14 min. 
30 sec. 
17 min. 
2 . 
30 sec. 
1 min. 
45 sec. 
2 min. 
45 sec. 
4 min. 
30 sec. 
5 min. 
30 sec. 
18 min. 
9 min. 
45 sec. 
3. 
18 min. 
5 min. 
5 min. 
2 min. 
15 sec. 
10 min. 
45 sec. 
7 min. 
30 sec. 
22 min. 
4. 
7 min. 
45 sec. 
13 min. 
30 sec. 
3 min. 
30 sec. 
1 min. 
4 min. 
13 min. 
30 sec. 
2 min. 
5. 
2 min. 
11 min. 
5 min. 
2 min. 
1 min. 
30 sec. 
2 min. 
3 min. 
6. 
9 min. 
3 min. 
30 sec. 
12 min. 
45 sec. 
1 min. 
30 sec. 
6 min. 
10 sec. 
3 min. 
