THE CANADIAN ENTOMOLOGIST. 243 



A REVIEW OF THE WORK ON THE POISONED BAIT 



SPRAY, DRY METHOD AND MIXED TREATMENT 



OF CONTROLLING FRUIT FLIES (TRYPETID^). 



BY HENRY H. P. SEVERIN, PH. D., MILWAUKEE, WIS. 



As the work on the poisoned bait spray for controlling fruit 

 flies is in its infancy in the United States and beyond the experi- 

 mental stage in other countries, we have decided to review some of 

 this work in order to set forth some of the methods employed and 

 results obtained. In this paper we shall take up the work of the 

 South African, French, Mexican, United States and Canadian 

 entomologists, and leave the results obtained by the Italian 

 entomologists for a future paper. 



It is a well-known fact that fruit flies, after they issue from 

 the pupa?, require 10 days or more before the egg-laying period 

 begins. This interval is a feeding period, and the flies subsist on 

 the nectar of flowers, waxy coating of fruit, juices of injured or 

 cracked fruit hanging on the trees, windfalls, fallen infested fruit 

 and droplets of water. Many fruit-flies show a great fondness for 

 sweets, and one can readily understand why poisoned sweets are 

 so effective in their control. If this poisoned bait is available with 

 the first appearance of the flies on the wing, no dcubt large num- 

 bers would be killed before the egg-laying period commences. 

 Mediterranean Fruit Fly (Ceratitis capitata Wied.). 



Mally (11) of South Africa, apparently unaware of the work 

 of the Italian entomologists started in 1903, began in the season 

 of 1904-5 to spray with poisoned molasses to control the Mediter- 

 ranean fruit fly, but his experiments were nullified by the scarcity 

 of the flies. Mally 's successor, Dewar (4), continued these experi- 

 ments during the seasons of 1905-7. His results were not conclu- 

 sive, but they were most encouraging. It was not until the sea- 

 son of 1908-9 that Mally (14) gave a decisive demonstration of the 

 success of the poisoned molasses to combat the Mediterranean 

 fruit fly under South African conditions. "A severe outbreak of 

 the pest in a commercial peach orchard was brought to a sudden 

 and practically complete halt, and the fruit maturing later was 

 marketed under the guarantee of freedom from maggots," while the 

 infestation of the fruit on the control trees increased until practi- 

 cally every fruit was involved. 



July, 1914 



