SYNOPSIS OF LAKV.r.. 47 



sides. Now, as is well known, the three images are 

 very similar, and were considered varieties of one 

 species before the larvae were known. Again, with 

 the luteus group of Nematus four of the larvae are flat 

 and green, while a fifth is cylindrical and reddish. 

 We find the same diversity with the dermal covering. 

 In Eriocampa we have slimy larvae, slimeless larvae, and 

 one covered with a white flaky substance. Hoplocampa 

 has spiny larvae, smooth colourless larvae living in 

 fruits, and gall -living larvae. The same diversity 

 exists in Blennocampa. Some very distinct larvae, indeed, 

 produce images which can scarcely be distinguished 

 from each other, e.g. Lophyrus pini and L. similis, 

 Nematus cadderensis, N.fagi, and N.fulvus, and others. 

 Contrariwise there are similarly-marked larvae which 

 give issue to very different flies. 



It thus becomes clear that the forms and habits of 

 larvae are entirely of an adaptive nature, and bear no 

 relationship with the habits, forms, and affinities of 

 the perfect insects. Each lives in a different sphere 

 and has a different food, has to contend against dif- 

 ferent enemies, and lives in entirely different sur- 

 roundings from the other. The lives of the flies, too, 

 are very uniform. Their chief business is to provide 

 for the continuance of the species ; when that has been 

 done they either die at once, or live a useless, lazy 

 existence for a few days, basking in the sunshine. 



In his Clams, Dahlbom has given a classification of 

 the Saw-fly larvae, which Westwood has reproduced 

 with additions in his Intr.* and Ent. Ann.f for 1862. 

 The following synopsis is carried out on the same lines, 

 but in much greater detail. 



Synopsis of Larvce. 



I. Larva with twenty- two legs. 



A. Ejecting from lateral pores a greenish acid liquid, 

 spinning a double cocoon. 



* ii, p. 97. f P. 129. 



