312 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 10 



lieved that all specimens of the worms found were "western army 

 cutworms." 



The cotton leaf perforator is a cotton pest which is evidently native 

 of the arid Southwest. It was originally found on the Arizona wild 

 cotton but has since appeared on cultivated cotton in the Salt River 

 Valley (15) and the Imperial Valley (11), strongly indicating that the 

 insect has other native food plants than the Thurberia. If, however, 

 the Arizona wild cotton is the insect's only native food plant and the 

 Salt River Valley infestation is traceable to this source, the insect 

 may have been carried to the Imperial Valley by means of cotton seed 

 shipments. Owing to the activity of parasites this insect is not 

 considered a very serious cotton pest although in 1914 it was very 

 abundant in the Salt River Valley and in 1916 in the Imperial Valley. 



The unidentified Thurberia or wild cotton bollworm is considered 

 by the writer to be more widespread and destructive to its food plant 

 than is the wild cotton weevil. The full grown larva is robust and 

 about an inch in length and the adult is therefore a moth which we 

 may presume to be fairly capable as a flier. ^ It is to be expected 

 that this insect will be found in the cotton fields of the Casa Grande 

 or Salt River Valley in Arizona within a few years. In captivity the 

 worms feed as readily on Egyptian cotton bolls and squares as upon the 

 Thurberia cotton and the importance of the insect as a pest will 

 depend on its adaptability to conditions in irrigated cotton fields at 

 elevations much lower than their present known limits. 



COLEOPTERA 



While the Mexican cotton boll weevil {Anthonomus grandis) has 

 made some progress into the western section of Texas it has not thus 

 far been able to fully adapt itself to semiarid conditions (8, 9, 10, 18). 

 This does not in the writer's opinion preclude the possibility of this 

 insect quickly adapting itself and proving injurious if introduced into 

 the extreme arid sections where cotton is grown entirely under irriga- 

 tion. 



The Thurberia or Arizona wild cotton {A. grand-is thurberia:) weevil 

 which is found only in and near certain mountain ranges in south- 

 eastern Arizona is properly regarded with apprehension. It is a form 

 of the cotton boll weevil which is thoroughly adapted to arid conditions 

 but at present it is harmless, and may remain so indefinitely. In the 

 event that it appears at any time in the future in the cotton fields 

 of the Casa Grande Valley — a new district where cotton will be grown 



^Attempts to rear the adult have so far been unsuccessful. Dr. H. G. Dyar, who 

 examined specimens of the larvae, noted that they resembled those of Sacadodes 

 pyralis, a worm which attacks cotton bolls in Trinidad. 



