HYMENOPTERA — SAW-FLIES, ETC. 



181 



EUURA (CnYrTOCAMPUs) PENTANDUiE, Caill. 



Large woody galls are formed by this insect on willow- steins, 

 generally of the species Salix jjentandrm. This insect is not at all 

 common, and certainly very local. Although the attacked bush is 

 often very valueless either from an aesthetic or an intrinsic point of 

 view, yet the galls are often so numerically strong as to do great vital 

 injury to the bush itself. An infested bush, from its extremely local 

 habits, becomes quite an interesting object. 



The galls themselves may be first noticed near the extreme end of 

 the twigs, being an enlargement on the twig (see fig. 168), about the 

 end of June. During the early 

 summer months the galls are of 

 a close Avoody structure, but 

 towards the autumn they are 

 more or less hollow, and contain 

 a comparatively large amount of 

 dirty black frass. Several larvae 

 are found within one gall. It 

 may happen on inspection that 

 each larva is enclosed within a 

 cocoon. This condition I found 

 on January .5, 1900, but it must 

 not be inferred that the larvae 



Fig. 168, 



"/ Euura pentandrje on shoots 

 alix peiitandra'. 



are fully fed, as the cocoon may 



be either for protection or shelter. 



The larvae commence making their pupal cocoons about the middle 



of April, for by April 28, 1900, they were all in the pupal stage. 



The larvae when full fed are about 8 to 9 mm. long, of a uniform 

 slaty-whitish colour, with darkish head. The six true legs are well 

 developed, and there are six pairs of thoracic legs. 



The flies hatch out from the 9th to the 1.5th of jNIay. The length 

 of the body is about 2 lines. Expanse of wings 6 lines ; antennae 

 9-jointed. Body wholly black ; legs brown, with darkish trochanters. 



PoNTANiA SALicis (Christ.) 

 Nematus belhtSy Zad. 



The galls are formed on the leaves of Salix caprece (goat willow). 

 It is geiaerally most abundant on hilly districts. In some seasons it 



