124 

 Parasitic Control of Insects. 



It will be observed, after a reading of the foregoing notes on the In- 

 jurious Insects of the Season, that parasitic and predaceous enemies 

 are an important factor in their control. For example, we find that of 

 the insects mentioned the tent caterpillar, bud- worm, cabbage-worm, 

 plum aphis, house fly, army worm are at least partially controlled by 

 parasites. Besides these, we know that PeriUiis circumcinctus, a pre- 

 daceous bug, is making headway against the Potato Beetle in some sec- 

 tions, that Lady-bird beetles and Syrphid flies are working havoc to plant 

 lice on infested plants, and that Ichneumon, Braconid and Chalcid flies 

 levy a heavy toll on cutworms and other of the larger caterpillars. 



While it is true that all or nearly all of our injurious insects have 

 their natural enemies, which often keep them more or less under control, 

 yet it must be acknowledged that no method of "mobilizing" these enenues 

 at the proper time so as to do away with spraying and other devices has 

 been discovered. The science of Entomology must advance much farther 

 before it can prevent insect outbreaks or meet them successfully by means 

 cf their natural enemies. That progress is being made, however, is shown 

 by the warfare against the Gypsy and Brown-tail moths, the Cottony 

 Cushion-Scale of California, and the Black Scale of Florida. 



At present the most hopeful line of control lies in the adoption of 

 better cultural methods and in the conservation of our insectivorous birds 

 Cultural or Preventive methods relate to those practices of culture or of 

 handling the crop that prevent or interfere with the development of insects. 

 Such methods are now used against the Hessian Fly, Cotton Boll-weevil, 

 Clover-root Borer, Wireworms, White Grubs, Cutworms including Army 

 worms. Chinch Bug, Grasshoppers, Apple Maggot and many others of 

 the most destructive insects. The fruit-grower, however, must depend 

 largely upon artificial or remedial methods for the control of fruit pests. 

 Thanks to the advent of the San Jose Scale, such methods have been 

 greatly improved in the last ten years by the adoption of better insecti- 

 cides and better spraying machinery. 



Lessons Learned. 



Quebec learned a valuable lesson this year and last from her experi- 

 ences with Tent-caterpillars. Owners who neglected to spray or otherwise 

 look carefully after their shade and orchard trees lost not only the shade 

 of the trees but also the season's fruit. It is surprising, however, how slow 

 the general public are to take timely measures for the protection of their 



