1921] Wheeler: Some Social Beetles 77 



in the course of several days gradually takes on the deep chest- 

 nut brown color of the mature insect. But before this stage is 

 reached, and while the male and female are still of a bright red 

 or pale chestnut red color, they mate. On two of the three occa- 

 sions on which I witnessed copulation both the male and the 

 female were immature. The third couple, observed, August 

 10, consisted of an immature female and a mature male. It 

 would seem, therefore, that mating occurs not only among im- 

 mature beetles of the same generation soon after they leave 

 the cocoons, but that old males of a preceding generation at 

 least occasionally fecundate the recently emerged females. 



The observation of August 10 is here transcribed from 

 my note-book. The female was distinctly immature but uni- 

 formly red, i.e. no longer in the white, callow stage, and dis- 

 tinctly smaller and more slender than the male. The latter was 

 certainly very nearly or quite mature. When first noticed the 

 female was eating the parenchyma of the petiolar wall. The 

 male mounted her back and remained for 18 minutes, clasping 

 her sides with his legs and occasionally attempting to insert his 

 aedoeagus. Now and then he rubbed her occiput from side to 

 side with his mandibles and antennae and sometimes shifted hi.'" 

 position very much to one side. The antennal movements were 

 precisely like those employed in titillating the coccids. The 

 female kept on feeding and pressed the tip of her abdomen 

 against the wall of the petiole so that the male was unable to 

 introduce his aedoeagus. He then dismounted and ran awaj. 

 but soon returned and attempted to mount and grasp the female 

 again, but she was unwilling, slipt out from under him and 

 escaped. He permitted her to go only a very short distance, 

 however, before he again seized her just as she had stumbled on 

 a coccid and had begun to stroke its posterior segments. While 

 the male was strenuously endeavoring to copulate she continued 

 to stroke the coccid and on this occasion kept the tip of her abdo- 

 men tightly pressed upward against the tips of her elytra. Then 

 the male again dismounted and left her and she and another 

 immature beetle turned their attention to a partly eaten larva 

 which they proceeded to devour. In a moment the male, appar- 

 ently in a high state of excitement, returned, mounted the 

 female and this time succeeded in introducing his sedoeagus by 



