4 A MANIAL OF DANGEROl'S INSECTS. 



Tliis compilatioji Avas only possil)lo by tJio cooperation of all the 

 ilivisions of the Bureau of Entomology, some of which prepared the 

 matter in the form in which it now appears. The editor therefore 

 wishes to acknowledge tlie assistance; of Messrs. C. L. Marlatt, W. D. 

 Hunter. A. 1). Hopkins, the late F. M. Webster, F. H. Chittenden, 

 A. L. Quaintance, W. R. Walton, E. R. Sasscer, Jacob Kotinsky, 

 Dwight Isely, II. L. Sanford, and R. W. Rust for the collection of the 

 notes on the insect enemies of the crops investigated by them, 

 and of Messrs. W. R. Walton, Harry B. Bradford, and the late J. F. 

 Strauss in the preparation of the illustrations. 



The lists of insects included in this manual are necessarily incom- 

 plet(\ and no doubt ijuportant species have been omitted. Fre- 

 (piently the lit(>ratur(> on dangerous species is so meager as to make 

 it impossible to conclude as to the importance^ of the species. 



R(>garding the nomenclat\n-e, it should be remembered that this 

 Avork is strictly a compilation. Many of the names will undoubtedly 

 be changed as the result of future studies. The ones used, however, 

 are the ones curr(>nt in European literature". To have attempted to 

 nuik(> the nomenclature more exact would have involved practically 

 the revision of many hirge groups of insects. This would have been 

 entirely impracticable and would have delayed publication of the 

 manual for years. Moreover it would have resulted in a publication 

 "which inspectors would have had diiliculty in using on account of the 

 fact that the literature accessible to them wouhl liave, in many 

 cases, used other names. In order to make future editions of this 

 handbook more useful, the bureau will be greatly obliged for criticism, 

 additions, and reconnnendations as to treatment. 



The majority of the insect pests in the Ignited States wiiicJi now 

 occasion the greatest damage to orchard, field, and garden crops and 

 to stored products and in homes, etc., are of foreign origin, and were 

 introduced with the host plants or accidentally in the course of com- 

 merce. Such introductions of new pests are going on all the time, 

 as illustrated by such recent arrivals as the Argentine ant in New 

 Orleans and the alfalfa leaf weevil in Utah. The list of over 100 

 introduced insect pests given below illustrates the nature of the 

 most important of these introductions in the past. This handbook 

 contains the names of hundreds of other insects which now occur in 

 different parts of the world and which are liable to be introduced at 

 any time with nursery stock or in merchandise or as accidental guests 

 or stowaways on ships or in baggage. It also includes a considerable 

 number of introduced pests which are not now generally distributed 

 and whicli therefore should be guarded against both as to further 

 entry and to furtluM- distribution within the United States. 



Throughout the work species which have been introduc(Ml into the 

 United States an* marked witli an ast(M'isk (jtc") and the fact of the 



