82 



FOREST ENTOMOLOGY. 



This genus is well worth careful study, more especially as they 

 prefer an arboreal diet ; and having regard to their hahit of pupating 

 within the skins of the injured leaf, they can be very easily hatched 

 artificially. The small size of the insects themselves, and the neces- 

 sity of magnification for the discrimination of specific characters, give 



an additional interest to the 

 study of the genus. 



The student should make a 

 careful study of the specific 

 characters as given by Fowler. 



f'jmi 



is 



& 



b 



f|<0> 



m 



Genus Cryptorrhynchus. 



Scutellum large and distinct 

 episterna of metasternum not 

 covered by elytra and well 

 developed. 1 



Cryptorrhynchus lapathi 

 (Linn.) 



This insect is often found in 

 the south of England, doing con- 

 siderable damage to alders of 

 the black and white varieties, 

 willows, poplars, and birch. It 

 generally attacks alders in pref- 

 erence to the other trees, and pre- 

 fers young trees from four to six 

 years of age. 2 The insect is 

 injurious both in the larval and 

 perfect forms. The beetle eats the bark and sapwood of young shoots, 

 and the larva gnaws under the bark, sometimes penetrating into the 

 pith, thus doing considerable damage to the young stems so much so, 

 that they break off and die. Fig. 78, a, b, shows typical damage. 



The beetle flies about the end of April or beginning of May. The 

 larva? are said to appear in about fourteen days after egg-laying, and 



1 Fowler, vol. v. p. 328. 



2 Commander Walker has always found it in and about osier-beds. 



:> 



Fig. 78, a, b. Larval burrows of Cryptorrhyn- 

 chus lapathi in alder stems. (From ' Forest 

 Protection,' by W. R. Fisher.) 



