THE OLFACTORY SENSE OF COLEOPTERA. 443 



They copulated as usual. They lived from ii to 40 days with 

 27.6 days as an average. 



(a) Effects with Antennce Cut Off. 

 Eight more Epicauta marginata were collected. Their antennse 

 were cut off at the bases. A small drop of amber-colored blood 

 exuded from each wound. Seven days later the two remaining 

 live ones were tested with the odors from the three essential oils. 

 The general average reaction time is 5 seconds. All these beetles 

 were abnormal in behavior. They lived from i to 8 days with 

 3.4 days as an average. 



(6) Effects with Antennce Pulled Off. 

 The antennae of 12 more Epicauta marginata were pulled off 

 at their bases. A small drop of blood exuded from each wound. 

 When tested with the odors from the essential oils three days 

 later, the eight remaining live beetles gave a general reaction 

 time of 5.9 seconds. They were less abnormal in behavior than 

 those with the antennae cut off. They lived from 2 to 13 days 

 with 5.5 days as an average. 



(c) Effects ivith Elytra and Wings Pulled Off. 

 The elytra and wings of nine Epicauta marginata were pulled 

 off at their articulations. A small drop of blood exuded from 

 each wound. When tested with the odors from the essential 

 oils two days later, the seven remaining live beetles gave a gen- 

 eral reaction time of 25.7 seconds. Two of them failed to re- 

 spond to each of the oils of peppermint and wintergreen. These 

 mutilated insects appeared normal in behavior and in confine- 

 ment they copulated as usual. They lived from 2 to 14 days 

 with 8 days as an average. 



The Olfactory Sense of Epicauta pennsylvanica. 

 Twenty-five blister beetles {Epicauta pennsylvanica) were 

 caught on golden rod (Solidago). This species has the same 

 habit of feigning death when mechanically irritated as has Epi- 

 cauta marginata. When tested with the odors from the essential 

 oils, they gave a general average reaction time of 11.5 seconds 



