Rev. F. D. Morice's Notes on Australian Sawflies. 313 



namely of structure and general appearance exhibited 

 almost without exception in their larvae. 



(i) The free movements of Tenthredinid larvae are greatly 

 assisted by their possession of well-developed thoracic legs, 

 jointed, and armed with claws, and also of " abdominal pro 

 legs " more or less like those of Lepidopterous caterpillars, 

 not indeed so elaborately constructed, but generally more 

 numerous (six pairs at least, and most commonly eight). 

 So far as is yet known, it is a rule to which, outside Australia, 

 there are no exceptions, that whenever the larva of a Saw- 

 fly feeds on leaves openly and moving freely about them, 

 it possesses abdominal pro-legs. On the other hand, such 

 pro-legs never occur among the Siricidae, and even their 

 thoracic legs are ill developed and jointless. Nor are pro- 

 legs developed in Pamphilius, etc. (whose larvae feed on 

 leaves, but keep always under cover, spinning silken webs 

 or rolling about themselves (like Tortricids) cases formed 

 from portions of the leaves on which they are feeding ; nor, 

 again, in the Cephidae which feed not actually in wood. 

 but as a rule oul of sight, in buds, berries, corn-stalks, hollow 

 or pithy stems, reeds, etc., and appear to be, both in habits 

 and structure, at least as nearly related to the Siricidae as 

 to the normal Tenthredinidce* 



(ii) The open life of a Tenthredinid larva exposes it to 

 many accidents and attacks of enemies, against which a 

 Siricid is to a great extent protected by its surroundings. 

 Hence in the former group many self -protective instincts 

 and " characters " have been developed, which would be 

 useless and are unknown among the Siricidae. Such, for 

 instance, are habits of dropping out of sight when alarmed ; 

 lurking under a leaf, when not actually feeding; emission 

 of nauseous odours and secretions ; assumption of "threaten- 

 ing attitudes," etc. Many species again have developed 

 protective colorations, cryptic or aposematic, etc., etc. 

 Nothing of the kind, naturally, is to be found among the 

 Siricidae. It is probable that their larvae have no instincts 

 but such as are common to all insects at that stage (feeding, 

 moulting, preparing in due course to pupate, and so forth) ; 

 and. like most animals which live absolutely in the dark, 



* In one or two (non-AusI ralian) genera, which on the whole must 

 lie reckoned as Tenthredinidae [Phyllotoma, Kaliosysphinga, etc.) 

 the pro-legs arc ill developed, though never perhaps entirely wanting. 

 Hut these are leaf-miners internal feeders and therefore no excep- 

 tions to the rule as stated above ! 



