2 ENTOMOLOGICAL NEWS [xxxii, '21 



sess very few structural characters in common, and are linked 

 together by such gradual changes and such great variations in 

 structure, within their respective limits of distribution, that 

 their classification presents great difficulties. 



The following notes are based upon observations and collec- 

 tions made with special reference to relation to cereal crops, by 

 the writer or other assistants of the Bureau of Entomology 

 in the states of Arizona, California, Colorado, Idaho, Iowa. 

 Kansas, Montana, Nebraska, New Mexico. North 'Dakota. 

 Oklahoma, Oregon, South Dakota, Texas, and Washington. 

 Thus far it has been found that species most injurious to grow- 

 ing crops are those within the genera Elcodcs, Embaphioii, 

 Blapstinus, and within the old genus Asida. It is probable, 

 however, that in the near future species within other closely 

 related genera will become pests upon the consequent destruc- 

 tion of native grasses and other host plants, and the cultiva- 

 tion of the soil. The injury to wheat and other grain is 

 wrought by the larvae in destroying the newly sown grain be- 

 fore and during its germination in the fall. 



Field surveys have been sufficiently extensive to secure data 

 of significance bearing on the distribution factors of the injuri- 

 ous species as related to possible control measures. Any notes 

 on local environment which throw light upon the various con- 

 ditions under which the insects occur in numbers, and under 

 which they might become serious pests, may afford valuable- 

 hints as to the most successful control measures, or may indi- 

 cate types of ground or other conditions to be avoided in 

 growing susceptible crops. 



Climatic limitations. The conditions of a region in rela- 

 tion to various phenomena of the atmosphere, such as tempera- 

 ture and moisture, forms an especially important factor in the 

 dispersal of these insects. It has long been known that these 

 insects, especially the Eleodiini, occur chiefly in arid regions; 

 thus, there are comparatively few species in the northeastern 

 United States, while there are many in the southwestern por- 

 tions of the country. 



Character of soil. ( )bservation has shown that the species 

 under consideration are found most abundantly, under similar 



