1868.] 175 



A LIFE HISTOEY OP ORACILABIA S7BINGELLA. 



BY CHAELES HEALT. 



(^Contmued from page 150.) 



These larvas show a great repugnance to feeding in an exposed si- 

 tuation, and, indeed, will not do it, possibly from a wholesome fear of 

 ichneumons ; if a larva be placed in a jar, on the outside of a leaf, 

 and not covered by another leaf, it crawls underneath and spins a 

 silken web, in which it then feeds ; but if a second leaf be placed over 

 the first, the larva is quite content to feed between the two, taking, 

 however, the precaution of fastening them together with silk. 



To recur, however, to the proceedings of the larva when it first 

 ceases to be a miner. It pierces the upper cuticle, and draws its body 

 through the hole and crawls to the under-side of another leaf, the tip 

 of which it rolls downwards ; this it efiects by spinning and fastening 

 silken cords until it pulls the tip of the leaf under, causing it to touch 

 the under-surface of the leaf : the larva then firmly fastens the tip 

 down with silk, and then creeps out of the roll and crawls along the 

 leaf till it has arrived near the centre of the cone, it then rapidly spins 

 several short silken threads, which it fastens to the rolled portion of the 

 leaf, and to that portion which remains flat ; it spins a number of such 

 threads, and then climbs up to the middle of these threads, and, holding 

 on by its prolegs, it stretches forth its anterior segments and spins and 

 fastens other longer cords, its body, whilst thus occupied, being swayed 

 backwards and forwards ; when these silken buttresses are completed, 

 they have a slight resemblance to the shoring of a house, but the objects 

 of the two are diametrically opposed ; the shoring of a house is to prop 

 up and support, — but the silken structure fabricated by this larva is 

 intended to pull down and retain in that position the rolled tip of the 

 leaf ; if the larva be then satisfied Avith the strength of the silken but- 

 tress, it descends and enters the rolled leaf, but if the silken stay be 

 not sufficiently strong, it spins two or three little silken cords at nearly 

 equal distances, on these it crawls and continues spinning similar silken 

 cords till it reaches the ends of the outside of its future habitation : 

 it then turns back, and passing over the newly-spun cords, climbs up 

 the large silken buttress near the centre of the rolled leaf,- it then 

 strengthens the ties of the remaining portion in a similar manner ; all 

 this being done with singular address, the larva never once touching 

 the leaf with its body : it then hastens back to the new-made domicile, 

 and proceeds to close up the two ends ; that done, it commences de- 

 vouring the epiderraes of both the upper and under-sides of the leaf, 

 which, in the rolled part, are in juxta position. 



