32 Journal New York Entomological Society. t^'o'- ^^• 



discovering a larva, at once proceeds to stroke its posterior segments 

 with the antennae. The ant also feels around over the surface of the 

 larva with its palpi. Very soon the evaginable organs of the eleventh 

 segment are thrust out, and the ant. in its explorations, invariably 

 touches one or both of these with its antennae, causing them to be 

 withdrawn. The ant immediately becomes greatly excited and darts 

 about over the larva and its foodplant, with its mandibles extended. 

 After several seconds it quiets down, and returns to its quest for food. 

 The ant may be thus disturbed several times before the slit on seg- 

 ment ten opens, and a sort of papilla is partially thrust out, bearing a 

 drop of a clear, somewhat viscous liquid. This the ant eagerly laps 

 up, stroking the larva with the antennas meanwhile. My observations 

 show that the larva of L. pimus emits a drop of this liquid about 

 every fifteen minutes. 



The majority of observers who have noticed the evaginable organs 

 at all, state that they are apparently used as signals to the ants. 

 Scudder (6), following Edwards (i), says, "the tentacles serve, 

 when erected, as indications to the ant that the feast is ready." I 

 have observed nothing that would lead me to this conclusion. The 

 organs of my larvae were usually partially protruded when the ants 

 were not close at hand, and occasionally one or both would be shot 

 out to the fullest extent, but I never saw the ants pay any attention to 

 them at these times. Thomann (7) and others think that the organs 

 diffuse some odor which attracts and fascinates the ants. I did not 

 discover any cells in connection with the organs, as will be seen later, 

 that might produce such an odor. Ray ward (5) has noticed that ants 

 attending the larvae of Lycccna corydon were momentarily distracted 

 by the appearance of the evaginable organs, just as I have described 

 from my observations of L. piasiis. My theory is that the sharp, 

 fang-like projections on the setae of the organs irritate the sensitive 

 antennae of the ant, and cause its excitement. It seems to be an 

 attempt on the part of the larva to rid itself of the attentions of the 

 ants when it is not able to satisfy their demands by giving up a drop 

 of the liquid. The organs are never protruded when the liquid is 

 emitted, nor while the ants are imbibing it. I was not able to bring 

 about the protrusion of these organs by touching the larva or by 

 any sort of rough handling. If the organs were already protruded, 

 thev were at once withdrawn, when the larva was touched. 



