544 TRANS. ST. LOUIS ACAD. SCIENCE. 



On the Larval Characters and Habits of the Blister- 

 beetles belonging to the Genera Macrobasis Lee. and 

 Epicauta Fabr.*; with Remarks on other Species of 

 the Family yiwLOYDJE.. 



By Charles V. Riley. 



[Read Nov, j, 1877.] 



The larval habits of the European Cantharis of commerce, as 

 also those of its congeners in our own country and in other parts 

 of the world, have hitherto remained a mystery, notwithstanding 

 the frequency with which the beetles occur, their great abimdance 

 at times, and their commercial value and interest. The same re- 

 mark holds true of the allied genera Macrobasis^ Epicauta^ and 

 Henous^ the species of which have the same valuable vesicatory 

 properties as Cantharis. Some of these species are very com- 

 mon in the United States and quite injurious to vegetation, 

 swarming at times on potato-vines, beans, clematis, and other 

 plants. Their great numbers and destructive habits make it all 

 the more remarkable that so little has hitherto been discovered 

 of their early life. Harris, who evidently had hatched the first 

 larva of the Ash-gray Blister-beetle {Macrobasis unicolor Kir- 

 by), says : "The larvae are slender, somewhat flattened grubs, of 

 a yellowish color, banded with black, with a small reddish head, 

 and six legs. , These grubs are very active in their motions, and 

 appear to live upon fine roots in the ground ; but I have not been 

 able to keep them till they arrived at maturity, and therefore 

 know nothing further of their history." {Ins. inj. to Vegeta- 

 tion, p. 138.) Latreille, according to Westwood, states that the 

 larvae live beneath the ground, feeding on the roots of vegetables 

 {Intr., vol. i., p. 301), but the statement is evidently founded 

 on conjecture. Ratzeburg, who well describes the method of 

 oviposition of the European Cantharis vesicatoria., and roughly 

 figures the first larva {Forst Insecten^ II., Col. Taf. ii., Fig. 27 



* As stated by Dr. Horn (Rev. of the Sp. of several Genera of Meloidae of the U. S.— 

 Am. Phil. Soc, Veh. 21, 1877), these two genera are very closely brought together by con- 

 necting species. There is certainly nothing in the adolescent habits or characters to sepa> 

 rate them. Yet the same thing may be said of almost any two allied genera when com. 

 prehensively considered, and I follow LeConte's separation because it facilitates study, 

 and because the species considered in this paper illustrate very well the differences on 

 which the genera in question are founded. 



