U. S. I). A., B. E. Bui. 95, Part I. C. F. I. I., March 3], 1911. 



PAPERS ON CEREAL AND FORAGE INSECTS. 



THE TIMOTHY STEM-BORER, A NEW TIMOTHY INSECT. 



(Mordellistena ustulata Lee.) 



By W. J. Phillips, 

 Entomological Assistant. 



INTRODUCTION. 



The writer's attention was first attracted, in 1904, to the interesting 

 little insect which is the subject of this paper. On November 29 of 

 that year, at Rives, Tenn., while examining timothy for joint-worms 

 (Isosoma), a curious little larva, unknown at that time to the writer, 

 was found tunneling the stems. In many cases it had traversed 

 the entire length of the stem, from the top joint to the bulb. Although 

 nothing was reared from this material it served to arouse interest. 

 Since that time, however, it has been reared and some interesting 

 facts learned concerning its habits and manner of living. 



Thus far it has not proved a serious pest, having been found only 

 in small numbers at any given point. In large numbers it would 

 scarcely do any perceptible injury to the hay crop, although it could 

 probably very materially lessen seed production. For this, as well 

 as other reasons, it deserves more than passing notice. 



HISTORY. 



The adult (fig. 1) was described by Le Conte in 1862, but there is 

 no reference in literature to its larval habits, although as early as 

 1877 it was known that larvse of other species of this genus inhabited 

 plant stems of different kinds. 



During the early part of November, 1904, Mr. Geo. I. Reeves, of 

 this Bureau, found larvse tunneling timothy stems at Richmond 

 and Evansville, Ind., and at Nicholsville, Ohio, but none was reared. 

 In the latter part of the month the writer found a larva working in 

 timothy stems at Rives, Tenn. Nothing could be reared, but in the 

 light of recent observations it is very probable that they were Mor- 

 dellistena ustulata in each instance. 



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