126 QUINCE CULTURE. 



side, black nectaries and tail appendage. The neck is 

 green, the body is yellowish green, striped often with 

 a deeper green. The young are almost white. The 

 wings are transparent, with dark veins. 



When they become gorged with sap, the excess is 

 thrown out through two little tubes, which project, one 

 on each side, from the anterior part of the body. These 

 are their nectaries, through which they eject a honeyed 

 fluid known as honey dew. To feed on this, a variety of 

 ants and flies will be found to visit them. The ants, 

 with whom they live on friendly terms, stroke the 

 aphides with their antennse to induce them sooner to 

 void this sweet liquid, which they hastily devour. 



Experiment has shown them capable of producing 

 eleven generations in seven months, when frost closed the 

 opportunity. In a heated room they continued to repro- 

 duce a constant succession, without the intervention of 

 males, for four years. Even then there was nothing to 

 show why it might not have been continued still longer. 

 Dr. Burnett considers this anomalous mode of increase 

 as a process of budding, and that the whole series, like 

 the leaves of a tree, constitute only one generation, 

 resulting from the previous union of the sexes. Reaumur 

 proved one capable of increasing to six thousand millions 

 in five generations. The leaves of trees infested with 

 aphides soon become distorted, or curled back so as to have 

 their tips touch the twig whence they sprung, thus pro- 

 tecting them from the sun and rain. 



Remedies. The eggs can be destroyed by a wash of 

 caustic lime or soda. The young may be destroyed by 

 alkaline solutions, and by tobacco water, made by boiling 

 a pound of stems in a gallon of water. Twigs can be 

 bent into it with but little waste of the solution. Small 

 birds in winter hunt over the trees for its eggs, and in 

 summer for the lice. The Ichneumon fly deposits her 

 egg in the aphis, and this soon produces a destroyer. 



