214 



The Alder and Osier Weevil. 



[JUNE, 



still better method is to set apart a small plot of ground and 

 grow yearly a sufficient number of each variety for trans- 

 planting, in which case the cuttings may be set 12 ins. 

 square. The tap root and also the longest and weakest of 

 the fibres should be shortened a little with a sharp knife, 

 care being taken to leave no ragged wounds to bleed when 

 active growth should be in progress. Only one shoot, the 

 longest and strongest, should be left on the head. A healthy 

 transplanted maiden head will never fail to establish itself. 

 In this way the life may be prolonged, as in the case of a 

 16-acre field at Wanlip, near Leicester, which, although 

 planted over twenty-five years ago, cut from six to eight tons 

 of one-year-old green to the acre, which realised £5 per ton 

 in January, 191 1. 



THE ALDER AND OSIER WEEVIL (Cryptorhynchus 



lapathi, L.). 



R. Stewart MacDougall, M.A., D.Sc. 



C. lapathi chiefly attacks and uses as brood places alder and 

 willow, while it also occasionally and exceptionally infests 

 birch and poplar. This weevil is found in England, where 

 locally it may be common ; it is not common in Scotland. 



Alnus glutinosa, Gartn., and Alnus incana, Willd., are 

 both infested, and attacks on Alpine Alder {Alnus viridis, 

 Dec.) have been recorded in the Continental literature. 

 Among Willows, Salix capraea, S. viminalis, S. purpurea, 

 and S. triandra are host plants. 



The Alder and Willow Weevil is destructive, both as adult 

 and as grub. Branches of alder, two years old and some years 

 older, are freely attacked, but poles of thirty years and more 

 do not escape. In the willow, young shoot and branch 

 and stem are attacked ; where in cultivation the willow shoots 

 are cut annually, the main stem is used as a place for the 

 brood. 



The damage is both technical and physiological; wood 

 tunnelled by the larva is spoiled, while branches that have 

 been attacked, but persist, are deformed. 



There is loss and destruction in various ways : — 

 (1) The grub eats out a space below the bark, spoiling both 

 bast and cambium. 



