RAVAGES OF CATERPILLARS. 219 



extraordinary number could not have failed to at- 

 tract public notice on other shores. The nature of 

 these insects is to lie in the pupa state durin<f the 

 winter under ground; and when, at its appointed 

 time, the Hy comes torth, it only lives to lay its eggs, 

 usually dying within a few days or weeks. It must 

 have been, theretoie, alter the laying their eggs on the 

 turnips, and not before, that clouds of the Hies were 

 seen at sea and on the shore, though not arriving, 

 but going away. They were, doubtless, impelled by 

 that restless desne of change tcit by all animals 

 when death is approaciiing, and which in tropcal 

 countries is yearly exemplified in the destruction of 

 locusts, for the^je always make for the sea, and 

 perish there. But though they were thus got rid 

 of in August, 1782, they left a progeny behind them 

 in the black catcr|)illars which were hatched from 

 their eggs. In the summer of 1783, accordmgiy, 

 we are tdid by IMr IMnrsliall, that whole districts 

 were ravaged !)> them, — the descendants, of course, 

 in the second generation, of the saw-flies which pe- 

 rished on the beach and at sea the preceding au- 

 tumn. 



Some caterpillars, which either conceal them- 

 selves under ground, or feed on roots and the wood 

 of trees, do considerable injury, without apparent 

 cause; and often give occasion to the popular notions 

 respecting mysterious blights. In this manner will 

 the caterpillars of the ghost moth (Hepialus Humuli) 

 gnaw ihe roots of the burdock, and. what is of more 

 consequence, of the h^p plant, till the shoots are 

 weakened and the leaves droop in bright sunshine. 

 We have repeatediv seen, in the gardens about Lee, 

 a large branch of the red-currant bush, though pre- 

 viously heallhv and loaded with fruit, all of a sud- 

 den droop and wither, giving good cause to sur- 

 mise, except in the leaves not being brown or 



