340 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1947 



of insects are either directly or indirectly beneficial to man or enjoy a 

 neutral status. Dr. Frank Lutz (8)^ has estimated that not more than 

 one-half of 1 percent of all the insects in the United States are actually 

 pests. Calling attention to Lutz's estimate, Paul Knight (7) states 

 that "those who care to extend the argument can show that a far 

 greater percentage are of direct value, but that would prolong a ques- 

 tion that is scarcely debatable." Nevertheless the beneficial aspects of 

 insect activities have not been brought clearly to the attention of people 

 generally. 



It is still too common practice on the part of entomologists, and in 

 particular of economic entomologists, since they must perforce focus 

 their attention on destructive species, to ignore or to minimize the 

 numerous benefits conferred on man by insects. For example, Graham, 

 in "Principles of Forest Entomology," (6) recognizes the beneficial 

 role of numerous forest insects, but dismisses them with a paragraph 

 of brief consideration in the final chapter.^ An occasional text, such as 

 "Destructive and Useful Insects," by Metcalf and Flint (9) devotes 

 a full chapter to the benefits that man derives from insects, and a very 

 few treat the subject at more length, but in the majority of texts the 

 treatment is quite inadequate. 



All too often, especially in articles designed for popular consump- 

 tion, we encounter extravagant statements and overdrawn pictures con- 

 cerning the so-called warfare between man and the insects as if the 

 two were engaged in a relentless struggle to the death. The "insect 

 menace" has become a catch phrase. To be sure, most of these fantastic 

 pictures are found in articles written by persons lacking entomological 

 training. Not a few, however, have been prepared by entomologists 

 who should know better and nearly all are based on information and 

 ideas that have been supplied by entomologists. An unfortunate con- 

 sequence of this state of affairs is that many, if not most, laymen have 

 developed the belief that nearly all insects are injurious and should 

 ruthlessly be exterminated. 



A few decades ago excessive emphasis on the destructive activities 

 of insects perhaps was justified. The increasing number of insect 

 pests required that public attention be directed to these enemies of 

 agriculture. Without this emphasis it might not have been possible 

 to arouse the public sentiment and the legislative backmg that were 

 essential for the support of needed research on pest control. At that 



^ Numbers in parentheses refer to bibliography. 



' The omission referred to here is the omission of any general treatment of beneficial 

 insect activities in the forest such as are dealt with here. There is no intent to imply that 

 Dr. Graham is unacquainted with these activities or unappreciative of them. Dr. Graham 

 is a good ecologist and his book contains numerous scattered references to the beneficial 

 activities of forest insects. The intent is merely to note that it has not been the custom 

 in general texts such as Graham's, concerned as they are with the control of insect pests, 

 to present beneficial insect activities broadly and as a whole, and so the student or general 

 reader is likely to underestimate their importance. 



