LAKGE GARDEN WHITE. 61 



In 1842, a vast. flight of white butterflies came ovei 

 from the Continent to the coast about Dover, and spread- 

 ing inland from thence, did an immense amount of 

 damage to the cabbage gardens ; but so effectually did 

 the ichneumon flies do their work, that an exceedingly 

 small proportion of the caterpillars, resulting from this 

 flock of immigrants, went into the chrysalis state, 

 nearly all perishing just before the period of change. 



Those small, silky, oval objects, of yellowish colour, 

 frequently found in groups on walls and palings, are 

 the cocoons of these useful little flies, spun round about 

 and over the remains of the dead caterpillar their vic- 

 tim. " These," as Mr. Westwood observes, " ignorant 

 persons mistake for the eggs of the caterpillar, and 

 destroy; thus foolishly killing their benefactors." 



Happily these devastating caterpillars have plenty of 

 enemies to prevent their continued multiplication, and 

 to reduce their number speedily when it exceeds certain 

 limits. Besides the ichneumons, mentioned above, the 

 feathered tribes do much towards keeping them down. 

 Mr. Haworth, in his " Lepidoptera Britannica" says, 

 with reference to this : " Small birds destroy incredible 

 numbers of them as food, and should be encouraged. 

 I once observed a titmouse (Parus major) take five or 

 six large ones to its nest in a very few minutes. In 

 enclosed gardens sea-gulls, with their wings cut, are of 

 infinite service. I had one eight years, which was at 

 last killed by accident, that lived entirely all the while 

 upon the insects, slugs, and worms which he found in 

 the garden." 



The pretty egg of this butterfly is figured on Plate 

 II. fig. 1 : it may be found commonly enough, with 

 a little searching, on cabbage-leaves, either at the end 

 of May or beginning of August. 



The caterpillar, which, besides cabbages, consumes 

 various other cruciferous plants, also Tropseolurns, or, 

 as they are erroneously called, "Nasturtiums/ 5 is green, 

 shaded with yellow on each side, and covered with 

 black points, on each of which is situated a hair. 



