432 N. E. MCINDOO. 



25 beetles tested to all six odors is 17.7 seconds. These mutilated 

 insects lived from 2 to 21 days with 9 days as an average. All the 

 time they were confined in the small box, they drank, ate, and 

 buried in the earth normally, but many times one was seen biting 

 the soft dorsal portion of the abdomen of another. With the 

 elytra and wings removed, the abdomens were unprotected and 

 many of them shrank considerably in size before the beetles died. 

 Some of these beetles were certainly killed on account of the 

 dorsal sides of their abdomens being bitten, because nearly 

 every one found dead had been entirely eaten except the chitinous 

 parts. In the other two boxes as already mentioned, only 

 occasionally was a dead beetle found that had been eaten. 



(c) Effects with Elytra and Wings Pulled Off and Pores on Legs 

 Covered with Vaseline. 



The elytra and wings of 1 8 Harpalus pennsylvanica were pulled 

 off at their articulations. Four days later the trochanters, 

 femurs and proximal ends of the tibise of these mutilated beetles 

 were covered with a vaselihe-beeswax mixture, consisting of 

 three fourths yellow commercial vaseline and one fourth beeswax. 

 An hour after the legs had been vaselined, the beetles were placed 

 singly into the experimental cases and were tested with the six 

 odors as usual. Most of them were comparatively quiet, but a 

 few were extremely restless. Their responses to odors were not 

 pronounced and were slow, otherwise they were similar to those 

 <of unmutilated beetles. 



Their reaction times are as follows: Oil of peppermint, 3 to 60 

 ■seconds, average 19.5 seconds. Three failed to respond to this 

 odor. Oil of thyme, 3 to 60 seconds, average 12.5 seconds. 

 Two failed to respond to this odor. Oil of wintergreen, 3 to 60 

 seconds, average 18.7 seconds. Four failed to respond to this 

 odor. Leaves and stems of pennyroyal, 5 to 60 seconds, average 

 38.6 seconds. Nine failed to respond to this odor. Leaves and 

 stems of spearmint, 3 to 60 seconds, average 32.9 seconds. 

 Seven failed to respond to this odor. Parts of decayed beetles, 

 4 to 60 seconds, average 22.1 seconds. Two failed to respond to 

 this odor. The general average reaction time of the 18 beetles 

 tested to all six odors is 24.1 seconds. Confined in a box similar 



