24 PROTECTION OF PLANTS, 1917-18 



in bark crevices, in the grooves of the outsides of wooden houses, etc. It is re- 

 commended to keep those cocoons through the winter in boxes covered with wire 

 netting, till spring, as they may have for tenants not only the chrysalis of the 

 Tussock Caterpillar but also the pupae of Diptera or Hymenoptera, parasites of 

 these caterpillars, and these would be killed if the cocoons were burnt in the fall. 

 If they are kept till spring, they will have a chance to survive and to help us to 

 destroy the coming caterpillars. 



One must also, 2nd, have recourse, in May and June, for the destruction of the 

 caterpillars, to the sprays used for the control of the tent caterpillar and other 

 kinds of insects. 



