METHODS OF INSECT CONTROL 



C. GORDON HEWITT, Dominion Entomologist. 



In this connection it is desirable briefly to indicate some of the more general 

 measures that may be adopted with a view of decreasing the annual loss due to insect 

 pests and to prevent widespread outbreaks. 



The first essential is clean farming. This involves the destruction of weeds; not 

 only because these enemies of the farm take the food and the place of the crop, but 

 because they also afford permanent breeding places for many insect pests. Fences 

 and hedgerows should be cleaned up. Rubbish and litter, under which numerous 

 noxious insects hibernate, should be collected and burnt. Where grain is grown, the 

 volunteer crop, which nourished certain cereal pests such as the Wheat Midge and 

 Wheat Stem Maggot, should be destroyed. After a crop such as cabbages or roots has 

 been harvested, clean up the field and burn the rubbish which would otherwise serve 

 as food and shelter for insects. A clean field and a clean orchard will mean larger 

 crops. 



Special attention should be paid to cultivation. If the ground is properly prepared 

 in the spring with a view to the production of a strong growth, the plants will be in the 

 best state to resist insect attacks. A poor growth cannot withstand insect injury. If 

 the crop has been attacked during the year by insect pests such as certain insects 

 affecting the stems of cereals or root-destroying grubs such as white grubs and wire- 

 worms, deep ploughing in the fall should be adopted. In the case of grain the stubble 

 is buried deep enough to prevent the emergence of insects which attack the plants 

 and are passing the winter in the soil. In the case of white grubs and wireworms, 

 which pass the winter at some distance below the surface of the soil, their shelters are 

 broken up and the unprotected tender grubs are in a large measure exposed to adverse 

 climatic conditions. Summer fallowing aids insect control. 



The rotation of crops is an excellent means of preventing or controlling certain 

 insect pests. The repeated sowing of the same crop provides a rapid means of increase 

 for insects affecting that crop. In certain cases the best method of controlling an 

 insect is to change the crop. There are certain facts which should always be remem- 

 bered : if land is infested with white grubs or wireworms, do not plant corn or potatoes 

 in the following year, but sow an immune crop, such as buckwheat or clover. Also, 

 grass land when put into cultivation is apt to be infested with root-eating insects such 

 as wireworms and steps should be taken accordingly. 



Too much stress cannot be laid upon the urgent necessity of protecting our native 

 birds, the majority of which constitute our most valuable allies in our war against 

 insect pests. Very few of our birds are really harmful; most of them destroy enormous 

 quantities of insects annually. The policy of the agriculturalist in regard to the birds 

 should be not only non-destructive but also one of active encouragement. The en- 

 couragement of birds about the farm involves little expense or labour. Nesting boxes 

 can be made out of rough slabs of lumber or old shingles; these should be distributed 

 about the farm or in the woodlot. Here and there on the farm a few bushes and 

 thickets should be permitted to grow to serve as shelters and nesting sites. The 

 shooting of wild birds should not be permitted on the farm. 



In conclusion, constant watchfulness should be practised. The first signs of any- 

 thing suspicious should be immediately investigated, and if there is any doubt as to 

 the cause of the trouble or its cure the Dominion or Provincial Department of Agri- 

 culture should be consulted without delay. Neglect to take action or delay may mean 

 the loss of a whole crop. 



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