74 FRUIT TREES AND THEIR ENEMIES 



blossom. The maggot, after hatching, feeds in the 

 blossom, which, instead of expanding, turns brown, 

 and dies, forming the so-called capped blossom. The 

 beetles hibernate under the rough bark of trees, etc. 



Remedies. — Winter- washing with caustic washes 

 destroys the harbouring places for the insects on the 

 trees ; keeping the surface of the ground clean and 

 free from rough grass and rubbish, is advantageous for 

 similar reasons. Spraying with a lime-salt wash is also 

 beneficial, owing to its delaying the opening of the buds. 



Scab (^Fiisicladium dendriticuni), — This is a fungus, 

 which causes the fruit to become covered with dark 

 patches, and prevents its proper development, often 

 causing it to crack. A similar fungus {^F. pirinuni) 

 attacks pears with a like, and generally worse, result. 

 In both cases it is the leaf which is first attacked, 

 dark patches appearing on the upper surface of it. 

 In winter the fungus occurs on the young wood, and 

 the spores hibernate in cracks in the bark, and on 

 fallen, diseased fruit. 



Remedies, — Destroy all fallen leaves and useless 

 fruits. If the disease is noticed on the young 

 wood, spray with copper sulphate (8) or the caustic 

 emulsion made with copper sulphate, in late winter, 

 and, if the disease appears in the following summer, 

 spray two or three times with Bordeaux mixture (9^ 

 or 9^) or with a weak emulsion containing a 

 fungicide (p. 62). 



Canker {N'ectria ditissimd). — This term is often 

 applied by growers to anything which results in the 

 destruction of patches of the bark and wood of trees, 



