668 



NOTES ON AUSTRALIAN SAWFLIES 

 ( TENTHRhWIXIDJ:). 



By Walter W. Fruggatt, F.L.S., (Iovernment Entomologist. 



The Sawtiies are well represented in Australia by a number 

 of handsome insects belonging to very distinctive genera peculiar 

 to our insect-fauna. 



While enormous numbers of the gregarious larva? of several 

 species of the genus Per^a are common at certain seasons (March 

 and April in particular), feeding upon the foliage of young gum- 

 trees {Eucalyptus) wherever there is plenty of young growth, 

 the perfect insects are comparatively rare. In breeding-out 

 specimens from the pupae, one finds that a large percentage of 

 them never reach maturity, because they are attacked in the 

 larval stage by many dipterous and hymenopterous parasites 

 which develop after the sawfiies have pupated. A great number 

 also fall victims to a mould-fungus, which destroys them in the 

 cocoons. 



Perga dorsalis Leach : The Steel-Blue Sawfly. 



Zoological Miscellany, iii., p. 11 7, t.l48, fig.l, 1817. 



This handsome sawfly, one of the largest and best known 

 species of the typical Australian genus Perya, has an extended 

 range round the coast, and is common in Victoria and New 

 South Wales. 



The gregarious larvje feed at night, and rest during the day, 

 clustered together in an oval mass, on the stem of the gum-tree 

 upon which they are feeding. When disturbed, they exude a 

 sticky yellow substance from the mouth, at the same time raising 

 the tip of the body, and tapping it down on the foliage. The 

 leaves are devoured from the top of the young gum-trees; and, 

 when the larvae are full fed, they crawl down the stem to pupate. 

 I have found them fully developed in the middle of April; but, 



