440 N. E. MCINDOO. 



leaves appeared "at home" just as much as they do in potato 

 patches. They ate the leaves, copulated and laid eggs as usual. 

 Up to the time of this writing (Jan. 15), 28 of the 45 beetles have 

 died. These lived from 14 to 151 days with 69 days as an 

 average. 



(a) Effects zvith Antennce Pulled Off. 



Twenty-nine more potato beetles were collected from the 

 potato patch. Their antennae were pulled off at the bases. A 

 small drop of blood exuded from each wound. These insects 

 were put into the wire-screen cage with the unmutilated ones. 

 Two days later the 23 remaining live ones were tested with only 

 the odors from the three essential oils. All of these beetles were 

 quite inactive and three failed to respond when tested. These 

 three also failed to respond when touched with a pencil. For this 

 reason they were discarded. The general average reaction time 

 of the 20 beetles tested is 3.5 seconds. As a rule these mutilated 

 insects appeared normal in all respects several days after having 

 the antennae pulled off, because they ate, copulated and were as 

 active as ever. They lived from 2 to 140 days with 38 days as 

 an average. 



(&) Effects with Elytra Pulled Off and Wings Cut Off. 



Thirty-one more potato beetles were collected. Their elytra 

 were pulled off at the articulations and the wings were cut off as 

 closely as possible to the articulations. A small drop of reddish 

 or yellowish blood exuded from each wound. The heavy veins, 

 extending from the base of the wing to where the wing folds, 

 contain most of the blood found in these wings. The elytra are 

 also filled with blood. The amount of blood in them gradually 

 diminishes from the base to the distal end. A day after being 

 mutilated 25 of these insects were tested with the six odors. 

 They were apparently normal in all respects except in their 

 slowness in responding to odors. They were as active as un- 

 mutilated ones and eight were extremely restless. Their re- 

 sponses were similar to those of unmutilated beetles, except 

 they were not pronounced. 



Their reaction times are as follows : Oil of peppermint, 2 to 40 



