2S2 



INJURIOUS INSECTS AND FUNGI. 



[Dec. 189C. 



Mr. L. O. Howard says that in the State of Virginia Sitotroga 

 cerealella passes the winter only in barns and storehouses, and 

 that it will breed uninterruptedly, generation after generation, 

 in stared wheat. In Mississippi, according to Professor Weed 

 there are at least eight annual generations. 



Methods of Prevention and Remedies. 



There appears to be no reason why this insect should not 

 become established in British grain stores and granaries, and 

 cause a considerable amount of mischief therein. It is unlikely, 

 however, that there will be as many generations in a year as in 

 the Southern States of America, but from the behaviour of the 

 insects in the samples of maize above alluded to, which were 

 kept in a cold room, it may be concluded that breeding would 

 go on at least from June to November in stores and granaries, 

 especially in large heaps of grain. 



Care must be taken to thoroughly cleanse and disinfest grain- 

 stores and granaries after infested grain has been placed in 

 them, as the moths creep into cracks in the walls, floors, and 

 partitions, and will lay eggs on the next grain that may arrive ; 

 or they will fly or crawl to grain in other parts of the 

 buildings. 



Cleansing and clisinfestation may be done by syringing cracks 

 and holes with strong soft soap solutions, as well as by scrubbing 

 with stiff brushes. 



As a remedy, only bisulphide of carbon appears to be 

 efficacious. This is largely employed in the United States, and 

 recommended by many economic entomologists, among whom 

 Professors Riley and Weed, Dr. Lintner, and Mr. Howard may 

 be cited. A small quantity of the bisulphide is placed on the 

 grain, which must be previously put into an air-tight, or nearly 

 air-tight, bin ; and the fumes, being heavier than air, descend 

 and permeate every part of the bin, killing all insect life within 

 it. , Used in this way, about one pound of bisulphide, costing 

 about 6cZ. wholesale, is required for each ton of grain. In some 

 granaries there is a bin specially made for this purpose, into 

 which all infested grain is put and treated. Mills and granaries 

 infested with this and other grain insects are disinfested by 

 placing quantities of bisulphide of carbon in open vessels in 

 elevated parts of the building. The mills are then closed as 

 tightly as possible, and the fumes of the bisulphide penetrate 

 everywhere, destroying all insects. If this is done on Saturday 

 night the place w 7 ili be clear by Monday morning. Fire, lights, 

 and lighted pipes must not be allowed near the bisulphide or in 

 buildings treated with it, as it is highly inflammable. 



Professor Weed says that a ball of tow, or cotton waste, 

 saturated with bisulphide of carbon, fastened to a stick and 

 plunged into a bin, or into a sack, has been advantageously 

 tried, especially if the bin is nearly air-tight. 



