Saw-Flies. 175 



This insect has a flat yellow body and four pellucid 

 wings, the two outer ones marked with brown on the edge. 

 In April it issues from the pupa, which has lain under 

 ground from the preceding September. The female of the 

 gooseberry saw-fly does not, like some of the family, cut a 

 groove in the branch to deposit her eggs ; " of what use, 

 then," asks Keauinur, " is her ovipositor-saw ?" In order to 

 satisfy himself on this point, he introduced a pair of the flies 

 under a bell-glass along with a branch bent from a red- 

 currrant bush, that he might watch the process. The female 

 immediately perambulated the leaves in search of a place 

 suited to her purpose, and passing under a leaf began to lay, 

 depositing six eggs within a quarter of an hour. Each time 

 she placed herself as if she wished to cut into the leaf with 

 her saw ; but, upon taking out the leaf, the eggs appeared 

 rather projecting than lodged in its substance. The cater- 

 pillars are hatched in two or three weeks ; and they feed in 

 company till after midsummer, frequently stripping both the 

 leaves and fruit of an extensive plantation. The caterpillar 

 has six legs and sixteen prolegs, and is of a green colour 

 mixed with yellow, and coveied with minute black dots 

 raised like shagreen. In its last skin it loses the black dots 

 and becomes smooth and yellowish white. The Caledonian 

 Horticultural Society have published a number of plans for 

 destroying these caterpillars. 



[Another remarkable mode of disposing of the pupa is 

 shown in the accompanying illustration ; it represents the 

 nest of an exotic saw-fly, named Deilocenes Ellisii. In this 

 instance, the numerous larvae unite in spinning for them- 

 selves a common envelope of considerable strength ; it is 

 seen as it appears when attached to the branch of a tree. 

 The material of which it is composed is the tough silken 

 fibre spun by the larvae of so many insects, which may be 

 seen in perfection in the cocoons of the Microgaster. Two 

 species of this curious group will be described in a future page. 



[By the side of the branch is seen a diagram of the same 

 nest, as it would appear in section. The irregularly angular 

 cells are seen in the centre, and around them is the common 



