S 1 8 SAWFLIES CHAP, xxir 



after which she sits over her brood witli outstretched legs, and 

 with admirable perseverance protects them, so far as she is able, 

 from the attacks of parasites and other enemies ; she quite 

 refuses to be driven away from her charges. Mr. Lewis, to 

 whom we are indebted for this account,^ states that the sawfly 

 does not recognise her own special brood, but will give equal 

 attention to another brood if she be transferred thereto ; and he 

 adds that many of the batches of larvae were destitute of any 

 maternal guardian. 



There are about 2000 species of sawflies known. A large 

 majority of them are found in the European and North American 

 regions ; still, a good many are known to live in South America, 

 and Perga — one of the genera of the family containing many 

 species of large size — is peculiar to the Australian region. 

 Although the family includes so many species, very few anomalies 

 of structure have been detected in it ; one species, Pompholyo: 

 dimorplia Freymuth, is described as being apterous in the female, 

 and as having the thorax curiously modified in its form. There 

 are no very small Insects in the family, and none over the middle 

 size. Nearly 400 species have been detected in Britain; this 

 number could certainly be increased by persevering researches. 

 The palaeontological record has hitherto given only a very 

 meagre evidence about sawflies. Several species have been 

 preserved in amber, and three or four are known from Tertiary 

 strata in Europe and North America. 



^ Tr. ent. Soc. London, i. 1836, p. 232. 



