Insects. 4547 



at which period the ridges of the surrounding walls presented a cu- 

 rious appearance, being occupied by a continuous string of the crea- 

 tures, generally travelling in the same direction. Last year a 

 favourite goal was the roof of a large house, near which an immense 

 host had been bred, and the walls, being white, rendered very con- 

 spicuous the unbroken dark line of the insects, which for some time 

 persevered in swarming up it, and which not merely entered the 

 rooms, but crept into the beds, among clothes, or into any other place 

 of concealment, the only remedy for the nuisance being to keep the 

 windows closed. Though the owner of the premises employed a 

 number of boys, his scholars, in sweeping with brooms the walls 

 leading to the house, their exertions produced no visible effect ; con- 

 sequently they were soon relinquished. A band of melted tar was 

 next drawn under the coping of the wall on the side whence the hos- 

 tile hosts proceeded, but to no good purpose, for when the vermin 

 reached the tar, they simply followed it to the extremity of the wall, 

 where it ceased, and then resumed their former course. The rate, 

 too, at which these little animals advance, is far more rapid than 

 would be imagined, though some attention will prove that their mo- 

 tions are really quick, their sole object during the journey appearing 

 to be to " move on." 



A large proportion of the caterpillars of 1853 took refuge in a malt- 

 house, from which they could not escape as butterflies, the result 

 being that for several weeks during the past spring and summer the 

 maltster swept up daily many hundreds (700 or 800 ! I was informed) 

 of the dead insects. Notwithstanding, though rather less numerous 

 than in 1853, they abounded quite sufficiently this year to cause the 

 annoyance and loss alluded to above, especially as they arrived in 

 successive swarms : if the garden had been completely cleared of 

 them, a fresh army was speedily to be perceived as busily engaged as 

 its predecessor. 



The 'Zoologist' for 1846 records (Zool. 1442, 1443) the immigration 

 about Dover from the Continent of an immense flight of white butter- 

 flies, in the beginning of July in the same year, and the pest, from 

 whatever cause it might proceed, certainly extended to this place, 

 the cabbages that season, partially if not generally, having been 

 entirely devoured. I then noticed for the first time the operation of 

 the ichneumon flies, the effect being that few or none of the cater- 

 pillars were observed by me in the chrysalis state, and that in 1847 

 the gardens were, if I recollect rightly, free from the ravages of the 

 preceding year. My experience on that occasion induced me to 



