232 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. 



INSECTS INJURIOUS TO STORED PRODUCTS. 



Investigations having for their especial purpose the control of 

 insects injurious to stored products, especially the grains and mill 

 products, dried meats, fruits, beans and peas, and various seeds and 

 foodstuffs have been continued under the direction of Dr. F. H. 

 Chittenden. 



The most injurious insect in this class in the past has been the 

 Mediterranean flour moth. This insect has been studied by the 

 bureau in Texas, Oklahoma, and Kansas, and to a less degree in other 

 States, and by State authorities in the principal milling regions of 

 the Middle West. As a consequence, much has been published on 

 this species, and millers as a general rule are thoroughly familiar 

 with the pest and with the best remedies for its suppression. During 

 the last fiscal year, however, there has been a revival of complaints 

 of its occurrence in flour mills and in commodities other than flour, 

 such as grains, milled and cooked cereals, nuts, and grist products 

 used for feed. Hydrocyanic-acid gas, carbon bisulphid or bisulphid 

 of carbon, and heat have all been employed under different condi- 

 tions for this and other pests, and various items in regard to methods 

 of control have been added to our store of knowledge on fumigation. 



The rice weevil, or corn weevil of the South, continues to cause 

 extensive damage to corn, rice, and other grains in store. Experi- 

 ments in the destruction of this species have been conducted, espe- 

 cially with heat. The granary weevil and some other insects have 

 attracted attention from their injuries to macaroni preparations and 

 have been investigated. 



The methods of wrapping and sealing cartons of cereal products 

 and dried fruits have continued as a project of investigation, the 

 round carton or paper can having been one of the items of study. 

 The belt bean heater designed for the destruction of weevils in beans, 

 especially the broad or Windsor bean, has been the subject of work, 

 and the broad-bean weevil has been under observation. This weevil 

 appears to be on the decrease, owing to the lessened production of 

 its food plant in California. Fumigation against the rust-red flour 

 beetle with hydrocyanic-acid gas was conducted in Virginia with 

 excellent results. Experiments have also been conducted to ascertain 

 the effect of heat on the volatilization of carbon bisulphid with a 

 view to standardizing the dosage required to fumigate under different 

 atmospheric conditions. 



The bean, pea, and cowpea weevils continue as a subject of investi- 

 gation, and much information has been furnished in regard to 

 remedies, for which there is constant demand. 



A feature of this work during the year has been the completion 

 of an investigation of the pink corn worm, an insect which infests 

 corn in the field and is destructive to corn and sorghum in the crib. 

 It has been particularly destructive in Mississippi, attracting atten- 

 tion throughout the State. It occurs in neighboring States in the 

 Gulf region, and in Arkansas, Tennessee, South Carolina, and 

 Georgia, and is apt to be troublesome at any time. It can be con- 

 trolled by fumigation with carbon bisulphid. A comprehensive 

 report on this species has been published as Department Bulletin 363. 



A pest which was described in last year's report as new to this 

 country has continued to attract attention from its injuries to cacao 



