June, '17] MORRILL: SOUTHWESTERN COTTON PESTS 315 



Orthoptera are listed for each section. Of the Coleoptera there are 

 six eastern cotton enemies and two western — counting Anthonomus 

 grandis and A. grandis thurberioe as two species. The order Hymenop- 

 tera contributes two species to the Hst of cotton enemies in the East 

 and none in the West, Homoptera two in the East and one in the West, 

 Thj'sanoptera none in the East and one in the West. Of the Acarina 

 there is one species which has proven injurious to Cotton in the East 

 and one in the West — this latter one being confined at present to wild 

 cotton. 



Eight species are injurious to cotton in both the humid and arid 

 sections while at least two of the eastern species, the false chinch 

 bug (Nysius angustatus) and the two-spotted red spider (Tetranychus 

 himaculatus) , are common in some and probably all of the cotton 

 growing localities of the arid Southwest but have not yet proven 

 injurious. 



A survey of the insect enemies of cotton is of special interest at 

 this time when the industry is confronted with the most serious menace 

 which has ever appeared on the North American continent. The 

 presence of the pink bollworm {Gelechia gossypiella) in the Laguna 

 district of northern Mexico (23) calls for the most vigorous measures 

 for its extermination for the protection of the cotton industry of the 

 United States, whatever difficulties may be involved in a problem of 

 this kind on foreign soil and even if the expense amounts to ten million 

 dollars or to twice this amount. Even the entrance of our country into 

 a great war in the interests of humanity should not blind us to the 

 danger in the existence of this insect at our very doors. There is no 

 single product of the soil which is of as great importance and so in- 

 dispensable to mankind as cotton and with our past experience with 

 the Mexican boll weevil and the extensive investigation of miscel- 

 laneous cotton pests made during the past few years it is now generally 

 acknowledged, East and West, even in new cotton-growdng chstricts, 

 that the continued success of this great industry is more dependent 

 on the exclusion, control and eradication of insect pests than on any 

 other factor. 



Literature 



(1) CoAD, B. R. Relation of the Arizona Wild Cotton Weevil to Cotton Planting 



in the .\rid West. Bui. 233, U. S. D. A., pp. 1-12. May, 1915. A con- 

 sideration of the subject named based on investigations conducted in 1914. 



(2) CoAD, B. R. Recent Studies of the Cotton Boll Weevil. Bui. 231, U. S. D. A., 



pp. 1-34. August, 1915. This includes a report of investigations of biology 

 of Anthonomus grandis thurberioe at Victoria, Texas, in 1913. 



(3) CoAD, B. R. Studies on the Biologj- of the Arizona Wild Cotton Boll Weevil. 



Bui. 344, U. S. D. A., pp. 1-23. January, 1916. A detailed report of life- 

 history investigations of Anthonomus grandis thurberioe made in 1914 near 

 Tucson, Arizona. 



