144 



FRUIT INSECTS 



Syrphus flies often reap a rich harvest of apple plant-lice. 

 These predaceous enemies, aided by several minute parasitic 

 flies, are very effective aids in reducing these prolific little pests 

 to much less injurious numbers. If it were not for these adverse 

 weather conditions, fungous troubles, and insect enemies, apple 



Fig. 156. — Dippin<j; tl 



tips of nursery trees in soai) solution for the control of 

 plant-lice. 



trees, especially large, bearing trees, would be much more fre- 

 quently overrun and severely injured by plant-lice. 



Remedial treatments. 



As all three of these common apple plant-lice pass the winter 

 as shiny black eggs, quite readily seen when numerous, and 

 laid mostly on the twigs, many of them could be removed by 



