268 THE CANADIAN ENTOMOLOGIST. 



the studies made as to the methods of distribution of the Gypsy moth, and 

 the measures practised for the destruction of the insect in its different 

 stages; spraying apparatus; and particularly the care of spraying machin- 

 ery ; methods of pruning ; and some charming observations upon insect- 

 eating birds. 



The scientific work contained in Professor Fernald's report is of 

 great value and contains a record of most painstaking and patient work. 

 Probably one of the most interesting sections is that which deals with 

 Natural Enemies, in which most excellent work has been done. Prof. 

 Fernald has been aided in this work by efficient assistants, and the whole 

 information so gained has been pieced together by a master hand. 



With regard to spraying, some surprising results have been obtained. 

 In the first place, the caterpillar of the Gypsy moth seems to be little 

 affected by applications of Paris green when applied of the strength 

 ordinarily used for other mandibulate insects. Mr. Forbush says : " It 

 became evident before the end of the season of 1891, that spraying, while 

 reducing the numbers of the moth, could not be relied upon as a means 

 of extermination, for many caterpillars survived its effects." 



The following conclusion, on page 139, will show entomologists that 

 the matter of controlling mandibulate insects, by means of active poisons, 

 is still a fertile field for careful work, in which useful and laurel-bearing 

 results are still to be reaped : — 



"Every effort was made during the spraying season to determine why 

 the results of spraying were not uniform and satisfactory. The feeding 

 caterpillars were watched day and night by many observers. The spray- 

 ing was most carefully superintended, and the conclusion finally arrived 

 at was that, under ordinary conditions, spraying with Paris green for the 

 Gypsy moth was ineftective and unsatisfactory." 



Paris green was on the whole the most fatal insecticide, and when 

 used in the proportion of one pound to 150 gallons of water, did not burn 

 foliage ; but with larger proportions, did considerable harm. The injury 

 developed so rapidly that within a short time the leaves were all killed 

 and the surviving larvae had to go elsewhere to feed. "Therefore, a 

 strong Paris green mixture had little better effect than a weak one. Lime 

 was then used with the Paris green, with a view of neutralizing the burn- 

 ing ; but considerable injury to the foliage still continued." 



Probably one of the most remarkable facts discovered by the ento- 

 mologists is related by Prof. Fernald, on page 476, where he says : "One 



