10 PRELIMINARY REPORT OX ALFALFA WEEVIL. 



proximity to any railway; it is, on the other hand, among the habita- 

 tions of the more humble class of people, such as have come from for- 

 eign countries. The correct inference, therefore, would seem to be that 

 it was introduced with nursery stock or in the household effects of 

 immigrants. The pest had gained a foothold, doubtless, years earlier, 

 but had increased from perhaps a single pair and was too few in num- 

 bers to attract attention up to the time when it had become destruc- 

 tive over several acres and when it had probably spread in limited 

 numbers far beyond. In the immediate vicinity of this seriously 

 infested field, and indeed throughout the country about Salt Lake, 

 alfalfa long ago escaped from cultivation and now grows as a weed 

 generally on vacant lots (PL I, fig. 1) and other uncultivated areas 

 like roadsides and railroad rights of way (PI. I, fig. 2), so that it 

 would now be impossible to determine, even approximately, the 



exact time and location of the original landing of 

 the first individuals in Utah. As a matter of fact 

 the insect might easily have been brought into 

 the country again and again and have perished 

 because the locality in which it ended its voyage 

 was destitute of growing alfalfa. 



SPREAD OF THE PEST. 



From the single infested alfalfa field near Salt 

 Lake, the only one known up to the year 1904, 



fig. i.-The alfalfa weevil the P est evidently became somewhat widely clif- 

 (Phytonomus posticus): fused and bv the following year was found sev- 

 vduit. Much enlarged } ^j (U ; tant to th sou theast. It was not, 



(Author s illustration.) 



however, until 1907 that it was brought to the 

 attention of the Utah Experiment Station and not until 1908 that 

 attention was called to the matter in print by Prof. E. G. Titus, 1 

 entomologist of the Agricultural College and Experiment Station, 

 although by the fall of 1907 it had spread over all of the alfalfa-grow- 

 ing section lying immediately east of Salt Lake and Murray. 2 By 

 July 1, 1910, the infested area covered the greater part of Salt Lake 

 and contiguous portions of adjoining counties, aggregating an area 

 approximately 60 by 70 miles in extent. 3 



Up to September, 1911, the insect had extended its area of diffusion 

 directly northward as far as Tremonton, east to Evanston, Almv, 

 and Lyman, Wyo., and northeast to Cokeville. Wyo., Randolph and 

 Laketown, Utah, and Fish Haven. Idaho. 



1 Deseret Fanner, Salt Lake City, Utah, September 20 and October 3, 190S. 



» Bui. 110, Utah Agr. Coll. Exp. Sta. The Alfalfa Leaf-Weevil, by E. G. Titus, Logan, Utah, September, 

 1910. 

 * Loc. cit., map 1. 



