HONEY-DEW 171 



hordes in rapid succession. Hence various kinds of aphides 

 are among the most dreaded plagues of agriculturists. The 

 'fly,' which Kentish farmers know so well on hops, is an 

 aphis specialised for that particular bine ; and, when once 

 it appears in the gardens, it spreads with startling rapidity 

 from one end of the long rows to the other. The phylloxera 

 which has spoilt the French vineyards is a root-feeding 

 form that attacks the vine, and kills or maims the plant 

 terribly, by sucking the vital juices on their way up into 

 the fresh-forming foliage. The ' American blight ' on apple 

 trees is yet another member of the same family, a wee 

 creeping cottony creature that hides among the fissures of 

 the bark, and drives its very long beak far down into the 

 green sappy layer underlying the dead outer covering. In 

 fact, almost all the best-known ' blights ' and bladder- 

 forming insects are aphides of one kind or another, affect- 

 ing leaves, or stalks, or roots, or branches. 



It is one of the most remarkable examples of the 

 limitation of human powers that while we can easily ex- 

 terminate large animals like the wolf and the bear in 

 England, or the puma and the wolverine in the settled 

 States of America, we should be so comparatively weak 

 against the Colorado beetle or the fourteen-year locust, and 

 so absolutely powerless against the hop-fly, the turnip-fly, 

 and the phylloxera. The smaller and the more insignificant 

 our enemy, viewed individually, the more difficult is he to 

 cope with in the mass. All the elephants in the world could 

 have been hunted down and annihilated, in all probability? 

 with far less labour than has been expended upon one single 

 little all but microscopic parasite in France alone. The 

 enormous rapidity of reproduction in the family of aphides 

 is the true cause of our helplessness before them. It has 

 been calculated that a single aphis may during its own life- 

 time become the progenitor of 5,904,900,000 descendants. 



