244 



FOREST ENTOMOLOGY. 



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the very tiny larvte bore into the leaves or suck the juices. The 

 damage is done from apex to base, for about half the length of the 

 leaf. The injured portion shrivels up, is light in colour, and therefore 

 very conspicuous. Meanwhile the larvae, when resting, bury them- 

 selves in the middle of the cluster of leaves, but they soon change their 

 mode of protection, as each individual larva forms a case for itself out 

 of the injured leaves. At first the case is very lightly coloured, but 

 it l)ecomes darker with age. The interior is lined with silk. When 

 the caterpillar is feeding, the case stands erect, with the head of the 

 larva downwards. The larvfB go on feeding in this way throughout 

 the season, so long as nourishment remains in the leaves, and then 

 hibernate for the winter. INIany of them go into cracks and crevices 



of the bark, or bury themselves 

 amongst the lichens. A consid- 

 erable portion of them lay them- 

 selves quite flat on the twigs, 

 and butt against the natural 

 ridges of the young twigs. The 

 light-coloured cases harmonise 

 well with the light-coloured 

 bark. In this way they pass 

 the winter, being perfectly im- 

 mune to the effects of frost. 

 As soon as the young larch 

 needles burst forth in spring the larvte wake up, carry their cases 

 back to the needles, and commence feeding in real earnest, thus giv- 

 ing rise to the characteristic withering already referred to. The 

 larvse now grow very rapidly, and the original cases become too small. 

 The tiny caterpillar then makes a fresh case. 



The larvre are a dark red-brown colour, and still darker head. Only 

 the anterior pair of legs are at all moderately developed, and, with 

 the exception of one anal pair of pro-legs, with which they fix them- 

 selves in the case, the pro-legs are also but poorly developed. There 

 is a black plate on the anal segment. The larva is about 5 mm. long. 

 The pupa is small and brownish-black. 



When the wings of the perfect insect are expanded they measure 

 about 4 or .5 lines across. The head and anterior wings are grey, the 

 posterior wings of a paler grey, and the abdomen of a blackish grey. 

 (Fig. 241.) 



Fig. 241.— Coleophora laricella. (From F. V. Tlieo. 



bald's 'Animal Pests of Forest Trees.') 



A, pupal case ; b, motli. 



