1928] 
Trophallaxis in Polistes pallipes 
153 
TROPHALLAXIS IN POLISTES PALLIPES. 
By Phil Rau 
Kirkwood, Mo. 
Wheeler, *in his paper on the origin of social habits, has given 
us some very interesting data on the mutualistic relationship 
between the mother or adult workers of insects and their larval 
brood. His data show that the relationship is clearly cooperative 
for ants, and he gathers from various sources similar data for 
other insects, and coins the word trophallaxis to encompass this 
phenomenon. 
In the orphan nests of Polistes pallipes we have often seen 
behavior substantiating Dr. Wheeler’s data, in a species where 
this type of behavior has not yet been recorded. The details 
more than substantiate the observations on other insects, be- 
cause the behavior we record can be only purely instinctive, 
since the observations were made on orphan colonies, with the 
queen and older workers gone before these individuals had come 
to light, and hence there was no possibility for the habits to be 
learned from others. 
On two occasions, I noticed that the foster-queen, just after 
feeding the larvae, would stand on the nest and make a prolonged 
grating noise by rapidly vibrating her body, wings and legs. 
The noise was one which I had never before heard, and which is 
probably a signal to the larva, for immediately after this per- 
formance she would poke her head into each of the cells. I 
suspect that by this process she obtained a drink of saliva, but I 
have no proof of this except that her mouth parts were protrud- 
ing and in motion when she withdrew her head. I suspected 
that she was going in for this purpose, and put my eye close 
enough to see when she came out of one cell; a large, glistening 
drop of liquid was in her mouth, which she soon swallowed. My 
1 Wheeler, W. M. A study of some ant larvae, with a consideration of the 
origin and meaning of the social habit among insects. Proc. Am. Phil. Soc. 
57 : 293 - 343 . 1918 . 
