310 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 10 



The western leaf-footed plant bug {Leptoglossus zonatus) which 

 has been noted as an enemy of cotton in northern Mexico (13) is very 

 abundant in parts of southern Arizona and has been taken on cotton in 

 the Salt River Valley and at Bard, California. Its favorite food is 

 the fruit of the pomegranate but it should be regarded as a cotton 

 pest owing to its known capability for damaging the bolls and oc- 

 casional injury to cotton may be expected from this species, as is done 

 in the humid cotton sections by its eastern relatives (L. phyllopus and 

 L. oppositus). 



The tarnished plant bug {Lygus pratensis and its varieties)^ was 

 observed by Mr. W. D. Pierce of the Bureau of Entomology as injurious 

 to cotton squares in the Imperial Valley in California in 1913 and the 

 same species has since proven quite destructive locally (16) in the 

 Salt River Valley in Arizona. Although this insect occurs throughout 

 the eastern cotton belt it does not appear to have attracted attention 

 as a cotton pest except in Arizona and California. 



Orthopteea 



Four or five species of Orthoptera have placed this insect order 

 ahead of the Lepidoptera and of about equal grade with the Hemiptera 

 in the total amount of damage to cotton in the arid Southwest. The 

 most generally destructive species is the differential grasshopper 

 {Melanoplus differentialis) well known also as a cotton pest in the 

 humid sections (15). In the Salt River Valley ranking next to the 

 differential grasshopper are two species of the genus Schistocerca 

 (*S. vega and S. shoshone) which are common in cotton fields and in one 

 locality in 1913 proved exceedingly destructive (14). During 1916 a 

 species of cricket was one of the most destructive cotton pests in the 

 Imperial Valley, necessitating the replanting of several hundred acres, 

 according to Mr. E. A. McGregor of the U. S. Bureau of Entomology, 

 who, in connection with his cotton insect investigations, is giving 

 special attention to this pest. Grasshoppers are also reported as 

 among the leading Imperial Valley cotton pests. 



Lepidoptera 



The arid Southwest has an extremely formidable list of lepidop- 

 terous enemies of cotton, although the combined damage so far 

 has not been very extensive. This list includes the cotton bollworm 



^The late O. Heideraann identified several lots of this material as "Lygus praten- 

 sis," "Lygus pratensis var. lineolarius," "Lygus pratensis var." and "Lygus sp. 

 near pratensis." Evidently Lygus pratensis is a variable species and it will require 

 special study to properly distinguish the southwestern forms as subspecies or to 

 prove that they are merely color varieties. 



