THE OLFACTORY SENSE OF COLEOPTERA. 435 



each wound. On the following day the beetles were tested with 

 odors. As a rule they were so inactive that they appeared life- 

 less. If touched while moving they feigned death and remained 

 inactive for several moments. When tested with odors most of 

 them worked the mouth parts; some moved away slowly; a few 

 vibrated one or more legs, and some failed to respond. 



Their reaction times to the odors from the three essential 

 oils are as follows: Oil of peppermint, 2 to 60 seconds, average 

 18.6 seconds. Three failed to respond to this odor. Oil of 

 thyme, 2 to 60 seconds, average 38.7 seconds. Fourteen failed 

 to respond to this odor. Oil of wintergreen, 3 to 60 seconds, 

 average 35.1 seconds. The general average reaction time to all 

 three odors is 30.8 seconds. Up to the time of this writing 

 (Jan. 15), 15 of these mutilated beetles have died. They lived 

 from I to 96 days with 22 days as an average. 



(b) Effects with Elytra and Wings Pulled Off. 



The elytra and wings of 10 Epilachna borealis were pulled off 

 at their articulations. A small drop of yellowish blood exuded 

 from each wound. A liquid of the same color is also present 

 throughout the elytra and in the veins of the wings. On the 

 second day after being mutilated, the four remaining live beetles 

 were tested as usual. They were very quiet, but appeared 

 normal in all respects except they responded to odors more 

 slowly than unmutilated ones. 



Their reaction times to the odors from the three essential oils 

 are as follows: Oil of peppermint, 10 to 60 seconds, average 25 

 seconds. One failed to respond to this odor. Oil of thyme, 5 to 

 60 seconds, average 33.5 seconds. Two failed to respond to this 

 odor. Oil of wintergreen, 7 to 60 seconds, average 35.5 seconds. 

 Two failed to respond to this odor. The general average re- 

 action time to all three odors is 31.3 seconds. Up to the time of 

 this writing (Jan. 15), i of these beetles has died. Counting the 

 7 mutilated beetles that died, they lived from 2 to 3 days with 

 2 days as an average. 



