460 HABITATIONS OF INSECTS. 



when their labour is completed 1 . — The habitation made 

 by a Tinea, which lives upon a species of Astragalus, is 

 in like manner formed of the epidermis of the leaves, but 

 in this several corrugated pieces project over each other, 

 so as to resemble the furbelows once in fashion 13 . 



Other larvas construct their habitations wholly of silk. 

 Of this description is that of a Tinea, whose abode, ex- 

 cept as to the materials which compose it, is formed on 

 the same general plan as that just described, and the 

 larva in like manner feeds only on the parenchyma of 

 the leaf. In the beginning of spring, if you examine 

 the leaves of your pear-trees, you will scarcely fail to 

 meet with some beset on the under surface with several 

 perpendicular downy russet-coloured projections, about 

 a quarter of an inch high, and not much thicker than a 

 pin, of a cylindrical shape, with a protuberance at the 

 base, and altogether resembling at first sight so many 

 spines growing out of the leaf. You would never sus- 

 pect that these could be the habitations of insects ; yet 

 that they are is certain. Detach one of them, and give 

 it a gentle squeeze, and you will see emerge from the 

 lower end a minute caterpillar with a yellowish body 

 and black head. Examine the place from which you 

 have removed it, and you will perceive a round excava- 

 tion in the cuticle and parenchyma of the leaf, the size of 

 the end of the tube by which it was concealed. This 

 excavation is the work of the above-mentioned cater- 

 pillar, which obtains its food by moving its little tent 

 from one part of the leaf to the other, and eating away 

 the space immediately under it, It touches no other 

 A Reaum. iii. 100430. & Ibid. 146 



