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Black Knot on Cherry and Plum. 



1302. Sir, — Would you kindly inform me if 

 spraying the trees with Bordeaux mixture is effec- 

 tual, not only in keeping down but also in getting 

 rid of the Knot until they are again affected by 

 other trees. Also, how early should the spraying 

 be commenced, and how often repeated? 



Listowel. A. J. Collins. 



Reply by Prof. Lochhead, O. A. C, 

 Guelph, Ont. : 



It is quite within the power of the fruit 

 grower not only to control but also to pre- 

 vent the spread of the Black Knot. If care- 

 ful spraying with Bordeaux mixture (4-4-40 

 formula) is carried on regularly the Knots 

 will gradually disappear by breaking off. 

 The disease is more profitably controlled by 

 cutting off diseased parts and burning them 

 in early spring, and by spraying with the 

 Bordeaux twice or thrice in spring and sum- 

 mer (such is necessary for the prevention of 

 the brown rot and the shot hole fungus). In 

 districts where the Black Knot was formerly 

 very injurious, but where cutting and spray- 

 ing have been adopted, the disease has prac- 

 tically disappeared. 



The best times to spray are: (i) When 

 leaf buds are opening ; (2) When fruit is 

 formed ; (3) Two weeks later. The spores 

 of the Black Knot are mainly set free in 

 early spring and in June, consequently the 

 Bordeaux should be^ applied at these times 

 at any rate to kill the germinating spores. 



Lecanium Scale on Japanese Honeysuckle. 



I303' Sir,— I enclose you some twigs of my 

 Japan honeysuckle affected with some kind of 

 scale. Could you tell me what it is ? 



A Subscriber. 



Reply by Prof. Lochhead, O. A. C, Guelph, 

 Ont.: 



The dark brown scales on the Japanese 

 honeysuckle sent me are Lecanium Scale 

 Insects. Similar scales are often found in 



both greenhouse and orchard plants. As a 

 rule they lay eggs, are but single-brooded, 

 and pass the winter in the half-grown con- 

 dition. On cherry there is the cherry scale 

 (Lecanium Cerasifex) ; on blackberries at 

 Trenton last year the blackberry scale j 

 (Lecanium Fitchi) ; on greenhouse lemons, •• 

 etc., the Lecanium Hesperidum ; on currants 

 the currant scale (Lecanium Ribis) ; on 

 peach, maple, etc., the peach Lecanium (L. 

 Nigrofasciatum) ; and on plums the New 

 York plum scale (Lecanium Prunusatri). 

 With the last named scale, the young pass 

 the winter on the twigs, and begin to move 

 in April to new feeding grounds on the 

 newer twigs. Before the end of June these 

 become full-grown, and begin egg-laying. 

 In early August the young lice emerge from 

 the eggs and crawl out on the leaves. In 

 September they migrate back to the twigs, 

 where they are to be found in winter cluster- 

 ed in rows on the under surface. 



The life-history of the honeysuckle scale 

 will likely be somewhat similar to that of 

 the New York plum scale. 



riillipedes Eating Strawberries. 



1304. Sir, — Can you give me a remedy for the 

 small brownish wire-worm that eats strawberries ? 



I do not mean the soft white grub that cats the 

 plant, but the harder and smaller inject that eats 

 the fruit itself. 



By doing so, you would greatly oblige. 



Montreal. Colin D. Morgan. 



Reply by Prof. Lochhead, O.A.C., Guelph, 

 Ont.: 



The hard, wiry, worm-like creatures 

 which you send me are millipedes, and are 

 sometimes mistaken for wire-worms. In 

 England, they are often called ** False Wire- 

 worms," and with us •' Galley-worms." 

 They do not belong to the insects, but to 

 the Myriapods. They never have wings, 



