June, '15] 



SEVERIX-SEVERIN: KEROSENE TRAPS 



329 



net, hospitals should be carefully screened, and wounded animals may- 

 be placed in screened stalls or have the wounds treated with pine tar 

 or other repellent substances. As has been said, infestation of wounds 

 which are produced by branding, dehorning, etc., may be prevented 

 "by arranging to do this work during winter. If possible, even in winter 

 it is well to choose a period when the weather is cool. The prevention 

 of infestation of sheep at lambing time may be accomplished to some 

 extent by lambing as early in the spring as feasible without danger of 

 severe storms. Of course the careful surveillance of all live stock dur- 

 ing the fly season is imperative. 



The methods of treating infested animals, as now practiced by stock- 

 men, seem to be fairly satisfactory. Of the larvae destroyers, chloro- 

 form is best as it has great penetrating power. Pine tar is one of the 

 best substances to place on the wound to prevent further infestation 

 after the larvse have been destroyed. Certain mixtures, many of which 

 contain carbon bisulphid, are being put up and sold by druggists for 

 the purpose of destroying the larvae and at the same time preventing 

 reinfestation. The fact that carbon bisulphid is somewhat attractive 

 to the adult flies renders the use of this substance inadvisable. 



The careful disposal of slaughterhouse offal by burning or deep 

 burying, the screening of abattoirs, and the use of screens wherever 

 animal food products are kept, will largely prevent the contamination 

 of these articles by the various blow flies. In cities the complete 

 disposal of garbage with incinerators is desirable. 



The relationship to this group of flies of certain mammals and birds 

 which act as scavengers is a subject of much interest and importance, 

 but space will not permit of its discussion here. We have also found 

 that climatic conditions may be important in controlling this class of 

 flies. The sun often destroys a large percentage of the maggots de- 

 veloping on a carcass. Where dead animals are not burned or 

 buried it is important to leave them in open places exposed to the sun 

 rather than in the shade of thickets, as is commonly practiced. 



KEROSENE TRAPS AS A MEANS OF CHECKING UP THE 

 EFFECTIVENESS OF A POISONED BAIT SPRAY TO CON- 

 TROL THE MEDITERRANEAN FRUIT-FLY (CERATITIS 

 CAPITATA WIED.) WITH A RECORD OF BENEFICIAL 

 INSECTS CAPTURED IN THE KEROSENE. 



By Henry H. P. Severin, Ph.D., and Harry C. Severin, M.A. 



Italian, French and South African entomologists gave striking 

 demonstrations of the effectiveness of the poisoned bait spray in the 

 control of different species of Trypetidae, and all obtained a great 



