86 OSIERS AND WILLOWS 



of the beds until the late spring, when the midges 

 will emerge and attack the new crop. 



(2) Indirect Measures. In addition to the direct 

 measures of control which can be applied to the grow- 

 ing crop there are certain precautionary measures 

 which are worth consideration as they would tend to 

 prevent the necessity for spraying. It has been 

 pointed out that willow beetles spend the winter in 

 heaps of rubbish, under bark, etc. It is, therefore, 

 obvious that all such heaps left until the spring are 

 a source of danger, while equally, if they are burnt 

 during the winter, they will have acted as traps, and 

 allowed the easy destruction of many pests. In the 

 same way it is probably a mistake to allow old pollarded 

 willows however picturesque to remain close to 

 willow beds. They are always thoroughly infested by 

 willow-feeding insects of all kinds, and must act as 

 centres from which these insects spread to the neigh- 

 bouring beds. If willow trees are needed they should 

 be of a variety which will pay for proper attention, 

 and they should not be pollarded. Neglected and 

 decayed willows, poplars or alders are all undesirable 

 in the neighbourhood of willow beds. 



Willow stumps which are partly dead or weak are 

 usually attacked by the insects which burrow inside, 

 such as the larvae of Cryptorrhynchus lapathi and of 

 the clear wing moths. Such stumps should be removed 

 and burnt as soon as the rods are cut. If they are 

 left, the insects will emerge and attack fresh stumps, 

 and the bed will gradually become unproductive. 



