244 THE CANADIAN ENTOMOLOGIST 



Fuller (5) in 1909-10, tested the poisoned bait spray to con- 

 trol the Mediterranean fruit fly, and all trials which were made in 

 several citrus orchards to control this pest were "attended with 

 remarkable effects." 



In 1912, Lounsbury (9) demonstrated the applicability of the 

 poisoned bait spray to town conditions. His work was carried on 

 under the most unfavourable weather conditions, for rain fell on 23 

 of the 33 days of experimentation. The garden in which the ex- 

 periment was performed contained 15 varieties of fruit, and, the 

 author states, "there is probably no other garden in Pretoria where 

 the fly finds conditions more favourable for its welfare." The 

 windfalls from three untreated trees showed respectively: 95)4, 

 95% and 98%% of maggoty fruit, against an average of 29% from 

 the treated trees, although the distance between the baited and 

 unbaited ones was only about 150 yards. The fruit picked from 

 sprayed trees showed that 13% was infested, whereas practically 

 every ripe fruit was maggoty on the untreated trees. The author 

 concludes, therefore, that if the spraying is properly carried out 

 the remedy is applicable under town conditions even where the 

 summer rainfall is heavy. 



The following formulas were used by these South African 

 entomologists : 



TABLE I. 



1904-5 1905-7 1908-9 191 z 



Molasses (gall.) 5 7 18 Brown sugar (lb.) 3 2 l A 6 



Arsenate of lead (lb.) 1 1 1 Paste arsenate of lead (oz.) ... 4 3 6 



Water (gall.) 25 25 25 Water (gall.) 5 4 8 



The lead arsenate and molasses or brown sugar in all of these 

 formulas were simply dissolved in the required amount of cold 

 water. According to Mally (13), the solution must be kept 

 thoroughly agitated, so that the bait will remain of uniform 

 strength. The spray should be applied so that the minute drop- 

 lets fall over and through the trees. A pint to a pint-and-a-half 

 is sufficient for a good-sized ten-year-old peach or nectarine tree. 

 Rain will dissolve and wash off the sweet ingredient, and the bait 

 should be renewed as soon as the weather permits. The number of 

 applications of the spray will vary according to local conditions 

 and the season. The first application should be made a month 

 before the presence of the maggots in the fruit is ordinarily ex- 

 pected, and after that an application after the expiration of every 



