14 FIRST ANNUAL REPORT OF THE STATE ENTOMOLOGIST. 



of the Sierra Neva'la, it has been seen filling the valleys below and the 

 air above as much higher as they could be distinguished with a good 

 field-glass.* Eich and fertile portions of Southern United States are 

 incapable of cultivation from the hosts of mosquitoes that abound in 

 them. The same insect effectually shuts out portiotis of British 

 America from exploration, while in Eastern Europe and in Asia the 

 attacks of its hosts have caused insanity in travelers, and the death of 

 domestic animals unprovided with means of defense. The experiments 

 of Reaumur have shown that a single aphis (a plant-louse) may, in a 

 single year, through its frequent generations without pairing, be the 

 progenitor of 5,904,900,000 (nearly six billions) descendants. 



Through such prodigious multiplication, the tiny, often despised, in- 

 sect attains an importance in the economy of nature to which the 

 ravenous beast of prey may not attain, although surpassing it many 

 thousand fold in size. 



5. Necessity of a Knowledge of Insect Habits. 



No great success can be expected in ourefforts to resist insect depre- 

 dations, until we know who and what our insect enemies are. We are 

 told who they are, Avhen they have been given the scientific name which 

 they shall bear wherever they may occur throughout the civilized 

 world ; and we are first prepared to learn what they are, when they 

 have been so intelligently described and faithfully illustrated that they 

 may be unmistakably identified by the agricultural, as well as tlie scien- 

 tific, student. Hundreds of persons, in different localities, may then be 

 simultaneously engaged in the study of the same insect ; or fact after 

 fact may be separately ascertained and recorded, which, when collated 

 and arranged, may so nearly furnish an entire life-history as to leave 

 but a few inconsiderable details for special study to supply. The 

 habits of the different species are so diverse as to necessitate separate 

 study of each one of the immense number with which we have to do. 

 Each history is a complicated one, as it embraces, for the greater part, 

 four distinct forms of animal existence — the Qgs,, the larva, the pupa, 

 and the imago — which may differ so greatly one from theotlier, that, 

 by the uninitiated, no relationship would be suspected. One or more of 

 these forms may be artfully hidden, or existing under such peculiar 

 circumstances as to elude discovery. Among the first hundred of our 

 most injurious insects, there are those which we only know in their 

 final stage, and there is not the naturalist among us who could iden- 

 tify them in their larval or their pupal state ; while at least one-half 

 of the number could not be determined in the agg. Such a confession 



*First Ann. Jt'ep. U. S. Entomolocf. Commix., 1S78, p. 213. 



