50 



control would be before the middle of May in a climate such as that 

 of the District of Columbia and about the middle of June in the 

 Northern States. 



■ Hot water; bisulphide of carbon. — Incase some of the larvae have 

 escaped before this operation is carried out. they can be killed in their 

 cocoons by drenching the earth about the plants with hot water. The 

 insects can be destroyed in hothouses in the same manner, as advised by 

 Miss Murtfeldt. If the degree of infestation does not justify the use 

 of hot water owing to the danger of killing the growing plants, bisul- 

 phide of carbon could be substituted and injected into the ground by 

 means of a McGowen injector, or some similar syringe in use for that 

 purpose, or by simply pouring it about where the cocoons are found. 



Arsenical poisoning. — The beetles, as previously stated, consume 

 quite a quantity of the tissue of the plant and feed about the edges of 

 the leaves in the same manner as do the cabbage flea-beetles. AVhere 

 it is found necessary to protect cabbages against cabbage worms and 

 other leaf -feeding insects, the Paris green or other arsenical used for 

 the purpose will also kill this curculio. and no other remedy should be 

 necessary. 



Other measures. — We should, however, avoid taking earth into the 

 greenhouse at a time when it is liable to be infested with these insects, 

 and particular attention should be observed that it be not taken from 

 the vicinity of cruciferous weeds. If the earth be sterilized, the heat 

 would kill the curculios or other insects which it might contain. 



It should be unnecessary to add that when the plants are found to be 

 badly infested the}' should be pulled up when their loss seems assured 

 and burned with their contained larva?. The application of kainit or 

 other fertilizer about the roots of less infested plants would assist these 

 in recuperating from attack. 



REMARKS ON THE FOOD HABITS 0E SPECIES OF CEUTORHYNCHUS. 



Forty-seven species of the true genus Ceutorhynchus. as at present 

 restricted, inhabit America north of Mexico, but the habits of only a 

 few of them are definitely known. Such of these as have been studied 

 live in their larval state on the Oruciferae. 



EUROPEAN SPECIES OF CEUTORITVNXHTJS. 



On the Eastern Continent species of this genus inhabit also plants 

 of other orders. In Europe alone 176 species have been recognized 

 (Catalogus Coleopterorum Europse, 1891). Of these, Bargagli (Ras 

 segna Biologica di Rincofori Europei. pp. 255-267) has recorded bio- 

 logic observations on 58 species, and in all save in a few cases mentions 

 the food habits. 



Among the European species of Ceutorhynchus which are enemies 



