London Insects. 153 



parent wings of Bees and Dragon Flies, and the 

 thick upper shields of the Beetles and Grass- 

 hoppers ; and this is the characteristic of many of its 

 members. 



But, as if to break the heart of the beginner, who 

 may have flattered himself that he had at last mas- 

 tered the first secrets of the entomologist's trade, 

 we find that there are whole families of insects be- 

 longing to the order which are wingless. All the 

 known " ocean insects," for instance, are classified as 

 " Hemiptera" 



There are several of them the naturalists of the 

 " Challenger " added to the number insects not un- 

 like the Gerris, the little slim long-legged Carnivora, 

 which are to be seen racing dryshod over the runs in 

 trout streams, but they have not a wing of any kind 

 among them ! 



One of the specimens of the order which flourishes 

 much too well in London is the Aphis, the common 

 Green Fly. It is an especial plague of town conser- 

 vatories, probably because our plants having other 

 difficulties to fight with from which their happier 

 fellows are free in the fresher air of the country, 

 have seldom strength of growth enough to make 

 head against such enemies. The flies seem to come 

 by magic. Two or three appear one day, and a week 

 or two later, if no strong measure is taken, every 

 young shoot is covered thickly. 



The explanation is that the Green Fly is among 

 the most rapid, possibly the most rapid, breeder yet 

 known, and, strange to say, is both " oviparous " and 

 "viviparous." That is to say, some of the females 

 give birth to living young ; others, born usually later 

 in the season, lay eggs. A single egg laid before the 

 cold sets in survives the winter frosts, and the first 



M 



