3954 Insects. 



most superficial observer. A young collector is often annoyed by the 

 circumstance of the uninhabited leaves being more conspicuous than 

 those in which the larvae are feeding. He looks around him, and ob- 

 serves leaf after leaf in which the larvae have been ; but though there 

 are many leaves before him in which the larvae are feeding, he passes 

 them over, the discoloration being so slight. 



The generality of the species mine the leaves in circuitous wavy 

 paths, of which examples may easily be seen on the leaves of the bram- 

 ble. Yet some mine in large blotches, as the species on the sloe, and 

 some in wavy tracks, so closely applied as to form a blotch, — no un- 

 mined portion of the leaf lying between the folds of the serpentine 

 path : an example of this kind may be met with on the elm. Others 

 mine in numerous concentric circles, as the species on the Hyperi- 

 cum, and that which Mr. Shield discovered last autumn, on the sorrel. 



In searching for the larvae of Nepticulae, the young collector must 

 not be misled by the numerous mining larvae of Dipterous insects, of 

 which an example may easily be found in the leaves of the buttercup, 

 sow-thistle, primrose, &c. The larvae of Nepticulae leave behind them 

 in their narrow mines, a continuous track of excrement ; whereas, in 

 the Dipterous mines, the excrement is scattered here and there. In 

 the case of the blotch-miner of the sloe, the excrement is usually in a 

 heap at the lower end of the blotch ; and in the leaves of the Rham- 

 nus catharticus and Clematis Vitalba, which have been mined by the 

 larvae of Nepticulae, the excrement appears to have been nearly of a 

 fluid nature, and does not form the ordinary series of little black grains. 



4. Where do the Larva of the Nepticulce assume the Pupa state f 

 In one solitary instance the larva does not quit the mined leaf, but 

 spins its cocoon therein, and changes to the pupa ; this is the species 

 that mines the Hypericum. All the other species yet observed, when 

 full fed, emerge from the leaf, and, I believe, usually descend to the 

 ground, where in all probability they spin their cocoons among the 

 withered leaves. The gallery-miner of the rose is the only species of 

 which we have yet learned to collect the pupae ; these may frequently 

 be found in the hollow of the footstalk of the leaf, or upon the stem, 

 sheltered by some projecting thorn or branch. Instances do occur, 

 though very rarely, of gallery-miners of the rose changing to the pupa 

 inside the leaf; the cause of this departure from the usual habit of 

 the species is yet unexplained. 



5. To obtain Specimens of Nepticulce, should we collect them in 



