152 THE EEPOET OF THE No. 36 



Parasite Woek. 



In addition to the spraying, which will control more and more Brown-tails 

 every year, as the amount of spraying increases, Mr. J. D. Tothil, of the Ento- 

 mological Branch, is supervising the colonizing of the various parasites. Besides 

 the colonizing of parasites, we have devised in Nova Scotia a practical means of 

 preventing the reducing in numbers of the imported parasite Apanteles lact&icolor 

 by the destruction of the winter webs of the Brown-tail. We build a large matched 

 board cage, about 5 feet high, 6 feet wide, and 12 feet long with an open top and 

 earth floor; two narrow boards are placed edgewise on the inside, and tanglefoot 

 placed on the underside as in the Fiske tray. All of the Brown-tail webs collected 

 are saved, and each of these cages stocked with two or three thousand of them. 

 The Brown-tails are fed on 'short, leafy twigs for about three weeks in the spring 

 until the first Apanteles larvae emerges to spin its cocoon, then they are fed on 

 willow catkins three or four times a day, giving them plenty of food so as to have 

 as little Brown-tail web as possible in the food containing the Apanteles cocoons. 

 The willow catkins seem to be the best material we can find for the Apanteles to 

 pupate in. After about one week's feeding on catkins and the majority of the 

 Apanteles have emerged, we feed broad leaves of some sort, heavily dusted with 

 Paris green. Two days feeding will usually kill all of the Brown-tails, and then 

 the green poisoned leaves can be rolled off to one corner and the willow containing 

 the Apanteles cocoons exposed, so that the adults can fly free as soon as they 

 emerge. 



OBSERVATIONS ON THE BROWN-TAIL AND GIPSY MOTH SITUATION 

 IN RELATION TO CANADA. 



J. D. ToTHiLL^ Field Officer, Dominion Entomological Laboratory, 



Predericton, N.B. 



The parasites and predators that Mr. McLaine has just spoken of are being 

 introduced of course as a measure of protection against possible injuries in Canada 

 from the Gipsy and Brown-tail Moths. 



How great a nuisance these two insects could become under Canadian con- 

 ditions is not known. The farther north they travel the more vigorous will be the 

 climate and the general conditions for existence. Somewhere between their 

 present range and the arctic zone they will cease to be injurious. If the exact 

 location of this " somewhere " could be precisely forecasted, fewer difficulties would 

 no doubt be experienced in dealing with the spread of the infestation in the future. 



The Brown-tail Moth, the less serious insect of the two, is now endemic in the 

 transition zone of Nova Scotia. This indicates that this insect could become, if 

 once established, a serious pest in all parts of the Dominion falling in this zone. 

 In the middle west, however, food supplies would be inadequate and the insect 

 would not be expected to flourish. The endemicity of Euproctis in the transition 

 zone of Nova Scotia indicates, therefore, that the insect would also ba a pest in the 

 transition portions of British Columbia, Alberta, Ontario, Quebec, New Brunswick, 

 and Prince Edward Island, if it once became established in any of these places. 



In boreal parts of New Brunswick, and most of the Province is boreal, the 

 same insect is epidemic. It remains to be seen whether or not it will become 

 endemic. 



