184 THE CANADIAN ENTOMOLOGIST. 



towards restricting the operations of these enemies to our forests ; yet 

 this should not deter us from studying their habits and history, since an 

 intimate acquaintance with these may result much more to our advantage 

 than we now anticipate. A few trees, such as a belt, or a group planted 

 for shelter or ornament, may be protected from the leaf and twig destroyers 

 by syringing with a mixture of Paris Green and water in the proportion 

 of a teaspoonful to a pail of water, and the bark lice may be killed by the 

 use of alkaline washes applied with a brush or broom, and a timely appli- 

 cation of the same will prevent the operations of the borers ; but it is 

 scarcely possible that such remedies can ever be applied over extended 

 areas of forest. It is, however, gratifying to know that in addition to the 

 numbers devoured by our insectivorous birds, that almost every injurious 

 species is in turn attacked to a greater or less extent by insect parasites 

 of the most active habits, who seek out and destroy these pests with 

 ceaseless diligence ; were it not for these friendly insects the destructive 

 species would be far more numerous individually than they now are. 



The question as to how best to check the increase of destructive 

 insects is of the greatest practical importance, and probably no insecticide 

 has of late played so important a part in this connection as Paris Green, 

 which is a compound of arsenic and copper, comparatively insoluble and 

 a substance which seems admirably qualified for the destruction of insect 

 life. Besides its special use as a potato-beetle killer, it can be successfully 

 used to destroy any and every insect which eats the leaves of plants, 

 shrubs or trees. So poisonous an agent should be handled with caution 

 if accidents are to be prevented, and it is a matter of great regret that in 

 consequence of carelessness in its use the lives of many valuable animals 

 have been sacrificed, and occasionally even human lives have been im- 

 perilled or lost. From the ease with which it can be procured it has also 

 been resorted to in several instances by those determined on suicide. 

 These unfortunate occurrences are greatly to be deplored, and every pos- 

 sible precaution should be taken to avoid accidents. It is quite a common 

 occurrence for painters, hardware dealers and general merchants to sell 

 Paris Green and to send it out without label of any sort, and sometimes 

 the parcel is very insecurely put up and packed with groceries and other 

 articles for home use in the most indifferent manner. Such recklessness 

 should not be permitted and no one should be allowed to sell any sub- 

 stance so dangerous unless it is properly labelled with the name of the 

 article and the word " Poison " prominently attached ; with such precau- 



