PSYLLID.K. 



3G7 



Fig. 342. Young form o/Psylla cratsegii 

 on shoot of hawthorn. 



The adult insects may he beaten from box plants, especially those 

 with rolled leaves, in showers throughout the summer months, and odd 

 specimens can also be beaten from 

 box-bushes during the winter months. 



An examination with the pocket- 

 lens will at once give the impres- 

 sion that the bodies of the tiny 

 insects appear " to have been made " 

 out of box leaves. In other words, 

 the colour of 'the insect, as compared 

 with the box leaves, is about the 

 best possible mimicry in the whole 

 realm of forest entomology. 



The prevailing colour of the insect 

 is sea-green. Head and thorax pale- 

 green ; antennae varying in colour 

 from yellow to brown. Wings 

 hyaline ; abdomen green ; legs yel- 

 lowish-green, with darkish tarsi. 

 Length 3 mm. 



Psylla ckaTjEGI (Schr.) 



The injuries caused by this insect 

 are not of very much importance, 

 and they are very apt to be over- 

 looked. They may be found either 

 on a hawthorn-tree or otherwise on 

 a switched thorn-hedge, but more 

 especially on the latter. Just as the 

 young shoots begin to grow the 

 larvae of this species (fig. 342) seize 

 hold of the extreme tip of the 

 shoots and fasten themselves to 

 it gregariously all round the tiny 

 twig. The result is that, through 

 sucking the juices, the inflated portion dies off, as in fig. 343 (a) ; and 

 meanwhile the tiny larvae remove themselves to the foliage, change to 

 winged insects, and remain on the foliage all through the summer. 



Fig. 343. Tip ofhawthom shoot inj 

 by Psylla crataegi. 

 a shows the injured portion. 



