COLEOPTERA. 



499 



remain constantly on trees. All are very brisk and active. When 

 swallowed they are a dangerous poison, but are used in medicine for 

 making blisters. 



The Cantharides of commerce (Cantharis \Lyttd\ vcsicatoria) are 



Fig. 539. Ctenostoma rugosa. 



Fig. 540. Therates labiata. 



of a beautiful green, attain to a size of four-fifths of an inch, and are 

 found on ash-trees, lilacs, and other shrubs. Commerce for a long 



Fig. 541. Blaps obtus 



Fig. 542. Tenebrio molitor 

 (larva and imago). 



time brought them from Spain, and some still come from that 

 country; hence the common name of Spanish fly. As they live in 

 great numbers together, collecting them is easier and less expensive 



