90 THE EEPOET OF THE No. 36 



exceptional facilities for spraying work with this pest. The orchards are small and 

 isolated, and a number of them suffer from very severe outbreaks of the maggot. 

 This gave us an opportunity of thoroughly testing the use of the sweetened poison 

 in this locality, since it was an easy matter for us to secure suitable orchards for 

 spraying, and take neighboring ones for use as check orchards. Five orchards 

 were accordingly selected in each district, three being treated twice with arsenate 

 of lead and molasses, and two left as checks. In checking up the results of our work 

 we counted, as nearly as possible, all the fruit from the experimental trees, a total 

 of 260,000 in 1915. 



The results of this work having already l)een published, it is unnecessary for 

 me to refer to them in detail, except to say that they were a striking success, though 

 the season was a very wet one. Orchards in which the fruit of susceptible varieties 

 had been a total loss for a number of years past, gave us fruit that was 95 per 

 cent, free from infection. 



A number of experiments were conducted during the season with flies confined 

 in cages over apple seedlings, which were sprayed with various poisons, both with 

 and without molasses. The results showed the interesting fact that, under these con- 

 ditions molasses was of no particular benefit. Though these conditions were not by 

 any means normal for the flies, this experiment suggested the possibility that the 

 molasses might be eliminated without lowering the efficiency of the spray. 



Next season additional orchards were chosen, making altogether three sprayed 

 and two check orchards at Windsor, and six sprayed and two unsprayed at Digby. 

 Three arsenicals, viz: lead arsenate, calcium arsenate and barium arsenate, were 

 used, both with and without molasses. Briefly summarized the results were, that all 

 these sprays effectively controlled the maggot, and that there was no noticeable 

 advantage in those containing the molasses. 



This fact that we have thus demonstrated experimentally is substantiated by 

 much indirect evidence. The most significant fact brought out by our inspection 

 is that both the badly infested districts are outside the main fruit belt, where 

 spraying has never been practised. As soon as we get into the well sprayed parts 

 of Kings and Annapolis, the pest begins to disappear. In spite of this, we have 

 been able to find the pest in the haws at various points throughout the Annapolis 

 Valley. In one such locality I have been informed that years ago there were severe 

 infestations of this pest in the orchards of the district, but that with the advent 

 of arsenical sprays it gradually disappeared. A very careful search also revealed 

 the presence of the insect in apples at widely separated points. Inquiry here also 

 elicited the information that formerly the pest was much worse in such localities, 

 but finally died out as spraying became general. 



There can thus be little doubt from the evidence on hand, that sprays of 

 arsenicals alone will control the apple maggot, and that the arsenical residues from 

 the sprays ordinarily apjjlied in the orchard are usually sufficient to keep it in 

 check. 



Prof. Caesar: I have listened with a great deal of interest and pleasure to Prof. 

 Brittain's paper, especially as liis results corroborate so fully those secured by Mr. 

 Eoss and myself during the last four years. Our first tests with sweetened arsenate 

 of lead as a means of control for the insect were on undivided trees or groups of 

 trees in an orchard instead of on the whole orchard, because at that time we believed, 

 along with most other entomologists, that this insect did not fly much from one 

 tree to another, but remained close to the same tree through its life. Our results 

 showed that if this were true, spraying with sweetened arsenate of lead was quite 



