65 



from hard lumps. The Paris green paste and the slacked lime are then 

 stirred into the required amount of water. The Paris green particles are 

 heavier than water and the spray mixture must be constantly stirred 

 while spraying is in process. When the caterpillars are over one- third 

 grown I20 gallons of w^ater should be used. 



Tree-tanglefoot is a commercial preparation and may be obtained 

 through dealers in insecticides. LEAD ARSRNATIC— This insec- 



ticide may be obtained in quantity in the form ol paste. This must be 

 worked up in a small amount of water before being diluted. It is used 

 on fruit trees and shade trees at the rate of tw^o pounds mixed in forty 

 gallons of water. This strength \vill readily control yoimg Tent-Caterpil- 

 lars, but the older ones, one third grown and over, need a stronger 

 spiray, four pounds per barrel (40 gals, of water). Lime is not needed 

 with this insecticide. 



When the hatching caterpillars are extremely numerous the stronger 

 sprays may be used w^ith advantage. 



In orchard practice these poisons are added to the fungicide used at 

 the rate given above. Paris green may be added to Bordeaux mixture; 

 leads arsenate to either Bordeaux or lime-sulplhur wash. 



It must be remembered that both Paris green and lead arsenate are 

 violent poisons. 



Shade trees may be most easily protected by spraying the infested 

 branches with lead arsenate as soon as the caterpillars appear, and 

 promply banding the trees with " tree-tanglefoot' or a similar preparation 

 as previously suggested, to prevent reinfestation. When spraying appar- 

 atus cannot be obtained, other means, recommended above, miay be em- 

 ployed to remove the caterpillars from the trees. 



THE DESTRUCTION OF USELESS TREES. 



It too often happens that useless and neglected apple, wild cherry, 

 and ha^vthorn trees are allowed to live in the neighbourhood of apple 

 orchards. On these the Tent Caterpillars, other leaf-feeding caterpillars, 

 certain boring-beetles and fruit pests breed imdisturbed, and readily 

 spread to near-by orchards. Particular attention should be paid by or- 

 chardists to the removal of these useless and dangerous trees, and, as al- 

 ready suggested, to the protection of our native birds. 



rhe Birch leaf Skeletonizer, ( Bucculatrix canadensisella ) . These 

 small green caterpillars skeletonize the leaves of birches. The caterpillars 

 spin small round white moulting cocoons on the twigs and leaves, and 

 later spin yellowish, ribbed, elongate cocoons within which they pupate. 

 Infestations by this species rarely last more than two years; for by that 

 time its natural parasites usually obtain control of it. The caterp^iUars 

 may be killed by spraying infested trees with Paris green or lead arse- 

 nate. 



