1875. 173 



it is nothing but a rigid and dormant larval stage, having its counter- 

 part in the well known " flaxseed " stage of the Hessian-fly larva and 

 in the so-called coarctate pupa of the Biptcra generally. A similar 

 dormant but less rigid larval stage occurs with many Tvntliredlnidas in 

 Symenoptera, and, in fact, the summer dormancy of certain Lcpidop- 

 terous larvae and the winter dormancy of others is analogous. We find 

 something similar, therefore, in all the Orders undergoing complete 

 transformations, but in no insects is the change so marked and excep- 

 tional or the freeing of the subsequent larva from the coarctate larva 

 so striking as in these Ileloidce. The insect has the power of remaining 

 in this coarctate larval condition for a long period, and generally thus 

 hibernates. 



In spring the coarctate larval skin is, in its turn, rent on the top 

 of the head and thorax, and there crawls out of it the Third Larva, 

 which differs in no respect from the ultimate stage of the second 

 larva already mentioned, except in the somewhat reduced size and 

 greater whiteness. The coarctate skin, when deserted, retains its 

 original form almost intact. The third larva is rather active, and 

 burrows about in the ground ; but while there seems to be no reason 

 why it should not feed, 7aoui'ishment is not at all essential, and all my 

 specimens have, in the course of a few days, transformed to the true 

 pupa without feeding. In the transformation to pupa the third larval 

 skin is worked into a wrinkled mass behind, as is also the skin of the 

 true pupa when shed. The pupa state lasts but five or six days, and 

 before the wings of the imago are fully expanded, or the abdomen 

 contracted, the general aspect of Epicauta forcibly I'ecalls the mature 

 Senous. 



The period of growth, from the first feeding to the coarctate 

 larva, averages, as will be gathered from the foregoing, about a month ; 

 yet in the month of September, out-doors, under screens whore I have 

 had the Differential Locust oviposit for the experiment, I have known 

 the full larval growth of vittata to occupy but 2J; 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 IIenous. 

 The characteristics of the triimgulins of the blister-beetles, represented by 

 Epicauta and llenous, are remarkably similar, and point to unity of habit. Tlio 

 slight differences of some arc given in the appended descriptions. Tiie same holds 

 true of the characters of the second, coarctate and third larva and of the ]iupa of 

 Upicauia and Macrobasis. They are precisely alike ; so that, while appreciable 



