^254 JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



within the province of the division of entomology, further comments here 

 are unnecessary. 



Destroying Borers in Trunks of Trees. 



A great deal has been written in favour of this use of carbon bisul- 

 phide. It is apparent that only the large borers which work in the trunks 

 and lower branches of trees will be good subjects for this treatment. 

 There are usually but few of these in each trunk, and the outlets of such 

 burrows as contain active borers are usually marked by the sawdust and 

 castings which the borers throw out therefrom. Only these burrows 

 should be treated. Clean-cut empty holes in the trunk indicate that the 

 insect has become adult and left the tree. It is therefore a useless waste 

 to inject the liquid into such holes. In Peach, Plum, Apricot, and Cherry 

 trees (all stone fruits) an abundant exudation of sap through the outlet 

 of the burrows causes a ball of gum, mixed with castings, to collect 

 around the hole. This should be scraped off before the treatment is 

 applied. 



Metlwd of Treatment. — Having cleaned out the mouth of the hole as 

 well as possible, inject a small quantity of carbon bisulphide and close the 

 hole tightly with a little grafting wax. This will quickly kill the borer. 

 The saving of time alone will fully pay for the small amount of carbon bisul- 

 phide required. The liquid may be conveniently applied by means of a 

 spring-bottomed oil-can. 



Treatment of Stored Products. 



Agricultural products are frequently brought together in storehouses, 

 mills, &c. in immense quantities, and when allowed to stand for some 

 time, as is often the case, become particularly favourable material for the 

 nourishment and multiplication of a large number of insect species. To 

 exterminate these necessitates the treatment of an entire room or 

 building. 



The Fumigation of Buildings.- - Carbon bisulphide is used in fumi- 

 gating milling establishments, warehouses, storage rooms, grain elevators, 

 stores, houses, barns, &c., for the destruction of insects affecting stored 

 cereals and vegetable products, manufactured food products, dried Tobacco 

 and its various products, drug-store insects, and household insects which 

 may be sufficiently numerous or injurious to warrant such treatment. 

 Besides being efficient for the destruction of such insects, it will also 

 kill other animals, such as rats and mice, which it may reach. The most 

 favourable time for application may vary somewhat, as will be shown 

 by the individual life-histories of the insects treated. It would require 

 too much space to mention all the minor details. 



Preliminary Investigation. — When a fumigation of this Kind is under- 

 taken, preliminary investigation should be made which should make clear 

 the nature of the pest, its habits, its injury, and as much of its life-history 

 as may be necessary to show whether one time will be more favourable 

 to treatment than another. The building or room should be examined, 

 its tightness ascertained, and its floor area and cubic contents computed. 

 Objections to treatment and unavoidable dangers should be considered. 



