LEPIDOPTERA. 



243 



insect, and the conspicuousness of the damage, the injury is often 

 attributed to frost. The general appearance, however, very much 

 resembles the action of frost or singeing by fire, inasmuch as the 

 leaves are half withered up, and practical foresters have therefore 



often associated this appearance with the commencement of 

 disease." It is, however, possible that this insect may play 

 important, though indirect, part in connection with the larch 



" larch 

 a very 

 :lisease 



Fig. 239. — Noniml foliage of 

 la rch. 



Fig. 2iO.—FoUaoe of larch injuml hy In 

 o/Coieopiiora laricella. 



fungus (Peziza Willkommii). The fungus is most active in spring 

 months, and as the injuries caused by G. laricella on the foliage, 

 together with the obvious effect of checking the rate of growth, have a 

 tendency to reduce the plant helow par, it follows that the fungus is 

 materially assisted in its action, and can therefore do greater damage. 

 Fig. 239 represents the normal foliage, and fig. 240 the injured shoots. 

 The small caterpillars which do this damage hatch out in July, and 

 feed on the leaves of young trees from six to thirty years of age, but 

 iis a rule they are most destructive to trees of the latter age. At first 



