PREFATORY NOTE 
If man were not the dominant animal in the world, this would be the 
Age of Insects. Outnumbering in kinds the members of all other groups 
of animals combined, and showing a wealth of individuals and a degree 
of prolificness excelled only by the fishes among larger animals, and among 
smaller animals by the Protozoa, the insects have an indisputable claim on 
the attention of students of natural history by sheer force of numbers. But 
their claim to our interest rests on securer ground. Their immediate and 
important relation to man as enemies of his crops, and, as we have come to 
know only to-day, as it were, as- a grim menace to his own health and life— 
this capacity of insects to destroy annually hundreds of millions of dollars’ 
worth of grains and fruits and vegetables, and to be solely responsible for 
the dissemination of some of the most serious diseases that make man to 
suffer and die, forces our attention whether we will or not. Finally, the 
amazing variety and specialization of habit and appearance, the extraor¬ 
dinary adaptations and “shifts for a living” which insects show, make a 
claim on the attention of all who harbor the smallest trace of that “ scientific 
curiosity” which leads men to observe and ponder the ways and seeming of 
Nature. Some of the most attractive and important problems which modern 
biological study is attacking, such as the significance of color and pattern, 
the reality of mechanism and automatism in the action and behavior of 
animals as contrasted with intelligent and discriminating performances, 
the statistical and experimental study of variation and heredity, and other sub¬ 
jects of present-day biological investigation, are finding their most available 
material and data among the insects. 
This book is written in the endeavor to foster an interest in insect biology 
on the part of students of natural history, of nature observers, and of general 
readers; it provides in a single volume a general systematic account of all 
the principal groups of insects as they occur in America, together with special 
accounts of the structure, physiology, development and metamorphoses, and 
of certain particularly interesting and important ecological-relations of insects 
with the world around them. Systematic entomology, economic entomology, 
and what may be called the bionomics of insects are the special subjects of 
the matter and illustration of the book. An effort has been made to put 
the matter at the easy command of the average intelligent reader; but it has 
been felt that a little demand on his attention will accomplish the result 
more satisfactorily than could be done with that utter freedom from effort 
