314 REPORT UNITED STATES ENTOMOLOGICAL COMMISSION. 



most active pursuers and devourers of the locust itself. The beetles of 

 this family {Carahidce) are essentially predaceous, and most of the larger 



species doubtless feed 



upon locusts when 



they get opportunity. 



The species which we 



have most often found 



at the work are the 



Fiery Calosoma {Colo- 



soma calidvm, Fig. 45, 



h) and the Elongate 



Ground-beetle {Fa si- fig.46.— pasimachuselox- 



GATUS. (After Eiley.) 



a 



Tig. 45, 

 larva ; &, beetle. 



Calosoma. calidum. 

 (After Eiley.) 



40). 



Fig. 48.— Cicindela 



REPANDA. 



machus elongatus, Fig, 

 In ditches, where the young had collected, we have also found at- 

 tacking them, Calosoma externum Say, 0. scrutator 

 (Fabr.), C. wilcoxi Lee, Earpalus caliginosus (Fabr.), 

 H. ])ennsylvanicus (De Geer), and JElaphrus ruscarius 

 Say. Mr. H. A. Brous also found Pasimaehus pmietula- 

 tus preying on them in western Kansas. 



Tiger-beetles. — These are swift-iunning and flying 

 beetles (Cieindeli^ce) withpredaceous habits, their larvae 

 living within cylindrical holes, and entrapping any un- 

 wary insects that may 

 Tig. 47. — hahpalus chaucc to come within reach 

 CALIGINOSUS. ^^ ^^^.^, formidable jaws. 



These larvse are characterized by the large 

 and flattened head, and by having two tuber- 

 cles on the back of the ninth joint, each 

 tubercle ending in two recurved hooks, which 

 support the creature in any part of its bur- 

 row. Various species ^^ in the perfect state are known 

 to attack the Eocky Mountain locust ; and Mr. J. K. 

 Moore, of Sairit Peter, Minn., sent us last summer the Cicindela re- 

 panda (Fig. 48) with the remnants of various specimens which it had 



partly devoured. One 

 would scarcely sup- 

 pose, however ,that the 

 stationary larvae of 

 these beetles could 

 succeed in entrapping 

 such an active creature 

 as our locust. Yet at 



^^^* Fig. 51.-Cici:5- 



June, we found that of dela vuxgaeis. 

 the young locusts which were collecting on the steep clay banks 



"Mr. Erous found the following species preying on spretus in Western Kansas in 1876: Cicindda 

 puUhra Say; C. scutellaris Say; O. 6-g'ittata Fabr.; C. fulgida Say; G. vulgaris Say; O. circumpicia 

 ''.af. ; O. for mo sa Sa.y ; 0-punctulata Fabr. 



Fig. 49.— Cr- 



CES'DELA 6-GITT- 

 TATA. 



Fig. 50. — CicixuELA splexdida.— a, larva; b, head Omaha, Is'ebr., 

 of same enlarged; c, beetle (Emerton, del.) 



