GARDEN PESTS 69 



that there are at least two natural enemies of these 

 insects, in addition to the cuckoo and other birds. One 

 is a tiny ichneumon fly rejoicing in the enormous name 

 of Microgaster glomeratus, and the other, which goes for 

 the Small White, a dipterous species called E. Vulgaris, 

 somewhat like a house-fly. Occasionally a caterpillar 

 is seen looking very sick and sorry for itself as it creeps 

 away into a corner. Presently we notice numbers of 

 tiny silken yellow objects all over the empty skin of the 

 unfortunate grub. These are the cocoons of the 

 microgaster and perhaps forty or fifty will come out of 

 one larva. 



If we avoid destroying these little yellow cocoons, the 

 friendly ichneumon will presently hold the White Butter- 

 flies in check. This Httle fly is Nature's censor on the 

 undue increase of the larger insect. In it we have a very 

 real cure for this pest, just as the plagiator fly shown on 

 Plate 8 keeps down the Corn Aphis, so much so that 

 naturahsts have talked about the Large Cabbage White 

 one day becoming a scarce butterfly. Certainly without 

 the tiny ichneumon, cabbage crops would have been 

 unmanageable long ere this. 



The Small White Cabbage Butterfly is also attacked by 

 H. Fulvipes, a hght-coloured ichneumon with yellow legs 

 and glassy wings measuring about I inch across. 



The grower will do well to familiarize himself with the 

 general form of these useful flies. All these strong- 

 looking, black, black and red, or bright-colom-ed insects 

 should be left to carry on their beneficial work unmo- 

 lested. (See Plate 3, Fig. 6, for the usual outline of an 

 ichneumon.) 



The Cabbage Tribe, as I said, are subject to numerous 

 pests in addition to the butterflies. Another bad one 

 is the Cabbage Moth {Mamestra brassica) whose larva 

 eats into the very heart of the plant. This insect mea- 

 sures about 1| inches across the fore-wings, which are 

 dark smoky grey in colour, mottled over with sepia 



