HTMENOPTERA (SAWFLIES). 165 



the rest of the mouth is weak. The sawflies lay their eggs by 

 cutting a slit in the epidermis of the leaf ; in this a single ovum 

 is deposited, and the slit closed hy a gummy excretion. The 

 larvae are called "False-caterpillars," and feed voraciously on 

 leaves and even fruit. They have twenty-two or more legs, and 

 can thus be told from the Lepidopterous larva. Often when 

 young the larvae are gregarious, but separate as they grow older. 

 They all, or nearly all, spin cocoons, which may generally be 

 found in the ground beneath where the larvae have been feeding. 

 The cocoons are often covered externally with small particles of 

 earth. They remain in this position all the winter — 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 {Eriocampa Umaeina), 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 Oooseberry 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 larVae 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 behiud the head and 

 near the tail, which retains the yellow colour. The Sawfly 

 appears in April, and may be seen settling on the gooseberry 

 leaves. It has four slightly iridescent wings, an orange abdo- 

 men, and black and yellow thorax : they vary from half an inch 

 to rather more than an inch across the wings. The female, 

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



