HYMENOPTEEA (SAWFLIES). 187 



— some as larvae, which pupate in the spring, others as pupae. 

 There may be two or more broods in the year. Some species, 

 such as the Slug- worm (Eiiocampa Umactna), are cosmopolitan, 

 doubtless having been distributed in the pupal stage in the 

 earth at the roots of nursery stock. The following are three 

 typical injurious species : — 



The Currant and Goosebeiry Sawfly {Nematus ribesii). 



Fruit-growers are constantly troubled with the "false-cater- 

 pillars " of this species on their gooseberry-bushes, and some- 

 times on the currants. The larvEe can be told by the number 

 of sucker-feet and the curious positions they assume, often 

 with the tail turned up over their back. They are bluish-green 

 in colour, spotted with black, and 

 marked at the sides with turquoise- 

 blue and yellow ; the first segment 

 and the last but one are yellow. 

 When full grown they reach half 

 an inch in length, and become 

 pale green, except behind the 

 head and near the tail, which 

 retains the yellow colour. The 

 Sawfly appears in April, and may 

 be seen settling on the goose- 

 berry leaves. It has four slightly 

 iridescent wings, an orange ab- 

 domen, and black and yellow 

 thorax : they vary from half 



an inch to rather jnore than an inch across the wings. The 

 female, which is larger than the male, cuts a number of little 

 slits in the leaf, along the edge, and in each she deposits a 

 single ovum. The eggs hatch out in about a week, sooner if 

 the weather is favourable ; the young larva feed close together 

 for some time. We can tell their presence in this early stage 



Fig. 90. — Gooseberry Sawfly 

 (Nemi'tus rihesii). 



1 and 2, Larva in two last stages ; 

 3, pupa; 4, imago. (Whitehead.) 



