ARTHROPODA 



199 



In Northern Asia Minor poisonous honey has recently been 

 reported. This phenomenon was described earlier by Xenophon 

 and Aristotle. The bees are supposed to secure toxic nectar from 

 two species of rhododendron. The toxic honey causes giddiness 

 and sometimes a brief loss of consciousness, followed by a short 

 period of general malaise " as though one had been on a spree." 



Worker Queea JDrone 



Fig. 93. Worker, queen, drone. (From Phillips, U. S. D. A. Farmers Bull. 447.) 



Methods of Insect Control. — Insects are controlled by poisons 

 acting through the alimentary canal or by contact. Sucking insects 

 are controlled by contact poisons while biting and chewing insects 

 are controlled by internal poisons. 



Contact Insecticides. — In the adult condition, the chief sub- 

 stances used as contact insecticides against sucking insects, such as 

 flies and bugs, are lime sulphur wash, whale-oil soap, kerosene 

 emulsion, tobacco decoction, miscible oils, pyrethrum, lime dust, 

 commercial sodium fluoride, carbolic acid emulsion, and white 

 arsenic. In the case of aquatic larvae like those of the mosquito, a 

 thin film of oil or a thin coating of some substance like Paris green 

 or pyrethrum proves effective. 



Stomach Poisons for Biting Insects. — In the case of the biting 

 insects attacking trees and vines, it is customary to spray or dust 

 with active poisons such as Paris green, arsenite or arsenate of lime, 

 arsenate of lead, hellebore, or sodium fluoride. Arsenate of lead 

 is used in preference to Paris green. 



The Use of Gases. — Repellants such as naphthalene are used to 

 drive insects away. Lime repels the striped cucumber beetle, while 



