84 



is released the paper will descend with the Gjanide and remain at rest 

 on the top of the jar but will not prevent the eas}^ descent of the cya- 

 nide into the acid. The weight of this paper will in no way interfere 

 with the escape of the gas. 



At the end of the time required for fumigation the windows and 

 doors should be opened from the outside and the gas allowed to escape 

 before anj^one enters the building. A general cleaning should follow, 

 as the insects leave their hiding places and, dj'ing on the floors, are 

 easil}^ swept up and burned. The sulphate of potash remaining in 

 the jars is poisonous and should be immediately buried and the jars 

 themselves filled with earti. or ashes. No food that has remained 

 during fumigation should be used, and thorough ventilation should 

 be maintained for several hours. After one of our experiments it 

 was noted that ice water which had remained in a closed cooler had 

 taken up the gas and had both the odor and taste of cyanide. 



For dwellings one fumigation each year would be sufficient, but for 

 storage houses it may be necessary to make an application every three 

 or four months to keep them entirely free from insect pests. The 

 cost of materials for one application is about 50 cents for each 5,000 

 cubic feet of space to be treated. The cyanide of potassium can be 

 purchased at about 35 cents per i3ound and the commercial sulphuric 

 acid at about 4= cents per pound. The strength of the dose may be 

 increased and the time of exposure somewhat shortened, but this 

 increases the cost and does not do the work so thoroughly. In no case, 

 however, should the dose exceed 0.22 gram, or remain less than one 

 hour. 



The practical application of this method of controlling household 

 insects and pests generally is to be found in checking the advance of 

 great numbers of some particular insect, or in eradicating them where 

 they have become thoroughly established. This method will be found 

 very advantageous in clearing old buildings and ships of cockroaches. 



INSECTS OF THE YEAR IN OHIO. 



By F. M. Webster and Wilmon Newell, Wooster, Ohio. 



Broadl}^ speaking, the past year has been marked by the unusual 

 abundance of many of the more common insect pests. 



During the past spring and early summer the chinch bug has done 

 serious injury over the area which seems particularly^ favorable to 

 it, viz, the countr}^ lyiug between the Scioto and Big Miami rivers, 

 which section is, approximately, the most frequently and seriously- 

 affected by it. As in other years, Sporotriclnim globidiferum, the 

 fungus enemy of the insect, has been distributed to all that have 

 applied, and the packages thus distributed amount to about 1,700 in 

 number. As this fungus has been continually sent into this region 

 since 1894, we can now state, with pretty good assurance of correct- 

 ness, that the artificial introduction thi-oughout this period has given 



