186 



Bulletin 87 



Pig. 13 — Egyptian cotton plant, showing work of leaf perforator. 



THE COTTON SQUARE DAUBERS 



The most destructive pests in Arizona up to this time are certain 

 sucking plant bugs of the tarnished plant bug group which, on 

 account of the characteristic effects upon the cotton plant, may be 

 called the "cotton square daubers"^ (Lygus clisns hespcnts Knight 

 and L. pratensis var. oblineatus Say). There are several closely re- 

 lated species and varieties of the tarnished plant bug genus and 

 while representatives are common in the eastern cotton growing 

 states, they have not so far proved destructive to cotton except in 

 the arid southwest. 



The cotton square daubers were first noted as cotton pests in 

 Arizona in 1914 when they became noticeably destructive in one 

 locality in the Salt River Valley a few miles southwest of Phoenix. 

 The next season they did sufficient damage in a large cotton field 

 near Glendale to make the crop unprofitable- Since then they have 

 been destructive in one locality or another each season-. In 1918 



^Seventh Annual Report, Ariz. Comm. Agr. & Hort., pp. 44-45. 

 'Eighth Annual Report. Ariz. Comm. Agr. & Hort., p. 49. Ninth Annual Re- 

 port, Ariz. Comm. Agr. & Hort., pp. 58-59. 



