82 THE REPORT OF THE No. 19 



Pear Scab. 



An interesting experiment to determine tlie effect of lime-sulphur upon 

 the Pear Scab, when applied much later than usual in the spring, was made 

 by Mr. Doughbrough, of Yineland. Mr. Doughbrough, as I have mentioned 

 above, sprayed some pear trees with lime-sulphur after the blossoms had 

 fallen. These trees had been badly affected with Pear Scab the previous 

 year. Some nearby trees were left unsprayed. The result was that the fruit 

 on the sprayed trees was very much cleaner than on the unsprayed. He 

 said that one could tell by a glance at the gathered fruit which belonged to 

 the sprayed trees, and which to the unsprayed. I have not had an oppor- 

 tunity of finding the effect upon the disease of spraying at the usual date. 



I have not been able in this one season to deal with all the prob- 

 lems that have suggested themselves to me in my study of this very use- 

 ful spray. There are many fungus diseases yet upon which I have either no 

 information or none that is valuable; for instance, apple scab, shot-hole 

 fungus, and powdery mildew of cherry. Moreover the effect upon many 

 insects and insect eggs has not been dealt with. No one orchard, probably 

 no one district, affords an opportunity to make experiments upon all of the 

 fungus diseases and insect pests which are to be found in this province. To 

 get as full information as is desirable experiments must be carried on for 

 several years and by several persons in different localities. The first year's 

 work, though quite valuable in direct results, is perhaps even more valuable 

 in showing what problems should be investigated and how to go about their 

 investigation. 



In conclusion there are a few points that should be mentioned : (1) It 

 is clear that the trees treated with lime and sulphur ought to show a more 

 thrifty appearance as a result. This was very conspicuous in many orchards 

 and my attention was frequently directed to it by the fruit-growers. (2) No 

 person should think that because lime-sulphur is such an excellent wash he 

 need use no other spray. It must not be forgotten that lime-sulphur is only 

 meant for a spring or fall wash and there are many fungus diseases and in- 

 sects that can only be controlled by the use of a summer wash in addition. 

 Poisoned Bordeaux mixture is, therefore, necessary to supplement lime-sul- 

 phur. In the careful use of these two spray mixtures lies the secret of much 

 of the success of our best fruit-growers. 



AN UNUSUAL OUTBREAK OF HALISIDOTA CATERPILLARS. 

 By Arthur Gibson, Assistant Entomologist, Experimental Farm, Ottawa. 



One of the interesting outbreaks of the season of 1907, has been the un- 

 usual number of the caterpillars of two Halisidota Tussock Moths, viz., the 

 Hickory Halisidota, Halisidota caryce, Harr., and the Spotted Halisidota, 

 Halisidota maculata, Harr. "We have no record of these insects being so 

 abundant and destructive in Canada, as they were during the past season. 

 In the United States, the Hickory Halisidota Tussock Moth has, on several 

 occasions, being recorded as doing much damage in limited localities. During 

 the present year the Hickory Halisidota while numerous and injurious in 

 Ontario and Quebec, was particularly destructive in the Maritime Provinces. 

 The Spotted Halisidota, on the other hand, while also troublesome to some 

 extent in Ontario and Quebec, was specially reported as doing harm in Mani- 



6a EN. 



