256 Insect Architecture. 



morphosed into a very minute weevil (Curculio Rhionoc.). 

 He says he Las been informed that, in warm climates, worms 

 an inch long are found in leaves, and adds, with great 

 simplicity, " on these many fine experiments might have been 

 made, if the inhabitants had not laboured under the cursed 

 thirst of gold."* 



The vine-leaf miner, when about to construct its cocoon, 

 cuts, from the termination of its gallery, two pieces of the 

 membrane of the leaf, deprived of their pulp, in a similar 

 manner to the tent-makers described above, uniting them and 

 lining them with silk. This she carries to some distance 

 before she lays herself up to undergo her change. Her 

 mode of walking under her burthen is peculiar, for, not con- 

 tented with the security of a single thread of silk, she forms, 

 as Bonnet says, " little mountains (monticules) of silk, from 

 distance to distance, and seizing one of these with her teeth, 

 drags herself forward, and makes it a scaffolding from which 

 she can build another."! Some of the miners, however, 

 do not leave their galleries, but undergo their transforma- 

 tions there, taking the precaution to mine a cell, not in the 

 upper, but in the under surface ; others only shift to another 

 portion of the leaf. 



SOCIAL LEAF-MINERS. 



The preceding descriptions apply to caterpillars who 

 construct their mines in solitude, there being seldom more 

 than one on a leaf or leaflet, unless when two mother-flies 

 happen to lay their eggs on the same leaf ; but there are 

 others, such as the miners of the leaves of the henbane (Hyos- 

 cyamus niger), which excavate a common area in concert 

 from four to eight forming a colony. These are very like 

 flesh-maggots, being larger than the common miners ; the 

 leaves of this plant, from being thick and juicy, giving them 

 space to work and plenty to eat. 



Most of the solitary leaf-miners either cannot or will not 

 construct a new mine, if ejected by an experimenter from 

 the old, as we have frequently proved ; but this is not the 



* SwammercL, ' Book of Nature,' vol. ii. p. 84. 

 f ' Contempl. de la Nature,' part xii. p. 197. 



