436 HOUSEHOLD INSECTS 



soles of the feet by means of their stiff bristles. A most 

 virulent poison is obtained from the larva of a Chrysome- 

 lid beetle, Diamphidia simplex, that occurs in Africa. 

 The African bushmen use the poisonous properties of these 

 larvae to poison their arrow heads. Some authorities 

 believe the poison is really due to a toxin produced by 

 some micro-organism growing in the decomposing larvae. 



The blister beetles of the family Meloidae possess 

 poisonous qualities. The powdered bodies of these beetles 

 are used in medicine for producing blisters on the human 

 flesh. The well-known European Spanish fly, Cantharis 

 vesicatoria, is most commonly used for this purpose. It is 

 distributed all over the temperate regions of Europe. 



We have several species of blister beetles in the United 

 States, many of which contain vesicant properties to a 

 greater or less extent. Many of our species are injurious 

 pests to plants, especially to potatoes, asters, and roses. 

 They come in great swarms, remain a few days, doing 

 much injury, and then suddenly disappear. The life 

 histories of these blister beetles are very complicated and 

 interesting. It has been shown that the larvae of some 

 species live upon the eggs of grasshoppers and in the nests 

 of solitary bees and pass through many remarkable 

 transformations before becoming adults. 



The vesicant properties of these blister beetles are due 

 to a peculiar, volatile crystalline substance known as 

 cantharidin. The powdered bodies of the beetles are 

 known to pharmacists as cantharides. The substance, 

 cantharidin, is soluble in alcohol, ether, or essential oils, 

 and externally it produces blisters, while internally it is a 

 violent, irritant poison. It is said that y-J-g- gr. put on the 

 lip will cause a blister. 



