556 TRANS. ST. LOUIS ACAD. SCIENCE. 



but 24 days. As this species occurs in the beetle state as early 

 as June in the latitude of St. Louis and as late as October, there 

 are possibly two annual generations here and farther south. 



Larval Habits of Macrobasis and Henous. 



The characteristics of the triungulins of the blistle-beetles, rep- 

 resented by Epicauta and Henous, are remarkably similar, and 

 point to unity of habit. The slight differences of some are given 

 in the appended descriptions. The same holds true of the char- 

 acters of the second, coarctate and third larva and of the pupa of 

 Epicauta and Macrobasis. They are precisely alike ; so that, 

 while appreciable differences may be found in the triungulins, it 

 is doubtful whether the subsequent developmental stages will 

 indicate specific or even generic differences in species of similar 

 size in these three genera. 



That the eggs of Epicauta may exceptionally hybernate is 

 possible, but, from their delicate nature, improbable. That the 

 triungulins frequently do so there can be no doubt, especially in 

 species like the Black Blister-beetle, which is found on the flowers 

 of Solidago, Eupatorium, etc., till the end of October, and con- 

 tinues laying till frost. I have at the present time many of these 

 last that are quietly huddled together, and, with winter tempera- 

 ture, will doubtless remain so ; while others have worked in be- 

 tween the locust eggs, there evidently to remain without feeding 

 till spring opens. I have also found as many as five triungulins of 

 this species curled up in the deep red mucous matter that sur- 

 rounds the eggs of CEdipoda phancecoptera — all numb and torpid, 

 and evidently hybernating. 



CONCLUSION- 



From the foregoing history of our commoner blister-beetles, it 

 is clear that while they pass through the curious hypermetamor- 

 phoses so characteristic of the family, and have many other feat- 

 ures in common, yet Epicauta and Macrobasis differ in many 

 important respects from Meloc and Sitaris, the only genera hith- 

 erto fully known biologically. To resume what is known of the 

 larval habits of the family, we have : 



1st — The small, smooth, unarmed, tapering triungulin of the pro- 

 lific Sitaris, with the thoracic joints subequal, with strong 



