232 



BRITISH BUTTERFLIES. 



Habits of larva. — The young larva makes its escape by cutting a 

 large round hole through the top of the egg. It then chooses the 

 upper surface of a small leaf of bramble, strawberry, potentilla, or 

 other foodplant, for its home, settling itself along the midrib, and 

 spinning several silken threads overhead for a covering, under which 

 it feeds by eating away the upper cuticle, and, when it has made a 

 blotch of some little extent, moves away and repeats the process on 

 another leaf ; as it grows bigger, still choosing the upper surface of a 

 leaf for its standpoint, it forms its covering by drawing down another 

 leaf over it, fastening the edges here and there with stout threads, and 

 feeds away in the cave thus formed. When larger, however,- it comes 

 out of its cave occasionally and feeds on leaves near. Its habit is to 

 be very sluggish, and the larva rests with its head curled round side- 

 ways towards its tail. The larval caves are not difficult to find on stunted 

 bramble bushes with small leaves, the large juicy leaves of strong 

 bushes apparently offering no temptation. In some districts the more 

 usual foodplant, however, is Potentilla frayariastrum . The larva is 

 fullfed at the end of August, remaining apparently dormant for days 

 together eating only at intervals ; pupation takes place in mid- September 

 (20th) (Hellins). On July 14th, 1905, several larvae in, or about to 

 enter, the 3rd instar, received from Dr. Chapman. They were feeding 

 in tents on leaves of cultivated strawberry ; placed on plants growing 

 in pots the larvae did not seem to thrive, probably owing to the dry nature 

 of the leaves. They appeared to be of too lazy or timid a disposition 

 to move from their tents and go to fresh leaves, so leaves were placed 

 in a bottle of water, and to these the larvae were transferred, being removed 

 to fresh leaves every three or four days ; under this treatment they 

 throve much better. On July 26th, they had all reached the 4th stage, 

 and two days later the most forward one entered the 5th stadium, and 

 by August 4th most of them had reached it. They always undergo 

 ecdysis in the tents. Though in the 4th stadium, the larvae spin the 

 leaves, which form their dwelling-tents, very firmly together, yet they 

 do not spin much silk over the floor of the tent. When in the 5th 

 stage the larva spins a fine silken carpet over that portion of the leaf 

 on which it rests. These tents are made by drawing the edges of the 

 leaflets together and fixing them with silk. Sometimes a larva will 

 rest on the upper surface of the central leaflet and draw the two edges 

 over it, but more often it rests underneath the central leaflet on the 

 veins of one side, and draws down the upper surface of one of the side 

 leaflets to form the cover. The two leaflets are held in place by a few 

 very strong strands of whitish silk. It takes the larva a long time to 

 spin its tent. In order to make the strands sufficiently strong, it has 

 to pass the spinneret over the strand many times. * Yet the silk is 

 strong, for once or twice a larva, even in the last stage, tired of crawling 

 on a paint-brush handle while being examined, has quietly let itself 

 down to the table by a silken thread. When feeding, the larvae eat 

 away the apical part of the leaves forming their tent, and parts of any 

 other leaves which may be within reach. I have never noticed them 

 feeding quite exposed, except immediately after being re-fed, when they 

 usually nibbled the fresh leaves before building a new tent. They 



® August 8th, 1905, watched a young larva of Augiades sylvanus making its 

 tube in grass. It passed the spinneret 33 times over one strand, which it had 

 already commenced before I noticed it (Sich). 



