27 



NXJTT ALL'S BLISTER BEETLE. 



( CunOiaris nuttalll Say. ) 



This species has several times been noted as injuring beets. The 

 beetle (fig. 22) is large and beautiful, usually of a bright metallic 

 green, the head and thorax having a coppery luster, the wing-covers 

 often purple. Its habitat extends from the Mississippi region to the 

 Eocky Mountains and from Canada to Nebraska. ^ 



Notes on the habits of this and several other species which have 

 been considered are published in Bulletin No. 40 (new series) of the 

 Division of Entomology (pp. 114-116). 



REMEDIES. 



Paris green is one of the best remedies for blister beetles when they 

 occur on beets, potatoes, and most other crops. It may be applied 

 dry, mixed with 10 to 20 parts of flour, plaster, 

 or air-slaked lime, or in the form of a spray, 

 also mixed with lime or Bordeaux mixture, at 

 the rate of a quarter of a pound of the poison 

 to 40 gallons of the diluent. Repeated applica- 

 tions are sometimes necessary, since the poi- 

 soned beetles are replaced by others. 



Owing to the rapidity with which many spe- 

 cies work, frequently in swarms of thousands, 

 poisons are of little value. We must, there- 

 fore, resort to mechanical measures for their 

 destruction, and in the employment of these 

 promptness and thoroughness are the essentials. 

 A remedy which is employed with success in the 

 Western States consists in sending a line of men 

 and bo3^s through infested fields to drive the 



beetles before them until they alight on a windrow of hay,' straw, or 

 other dry vegetable material which has previously been prepared along 

 the leeward side of the field. When the beetles have taken refuge in 

 such a windrow, it is fired and the beetles are burned. The beetles 

 may be destro3'ed by sweeping them into a net, such as is used by 

 insect collectors, and throwing the captured insects into a fire; or 

 by beating them into large pans of water on which there is a thin scum 

 of coal oil. The latter remedy is successful over small areas. 



After what has been said concerning the voracity of these beetles it 

 is almost superfluous to add that whatever remedy is employed should 

 be applied at the outset of attack in order to be of substantial value. 



Fig. 22.— Cantharis nuttalli: fe- 

 male beetle, one-third larger 

 than natural size (author'3 

 illustration, Division of En- 

 tomology) . 



« Yearbook U. S. Dept. Agr. for 1898, pp. 250-251. 



