50 REPORTS OF OBSERVATIONS AND EXPERIMENTS. 



attracted more attention from farmers this season than at any time 

 heretofore. So plentiful was it during the latter part of the summer 

 that there seemed no possibility of a profitable crop of clover seed, and 

 where it occurred in abundance the recommendation was made that the 

 clover be cut before the larvae had matured or else pastured heavily, 

 with the hope of destroying as many of the larvae as possible and pre- 

 venting a late fall brood of this species, which feeds largely upon the 

 leaves and at the base of the stems and later hibernates, to mature in 

 the spring. 



The Sod Web worm. — The sod web-worm, Crambus exsiccatus, was 

 more plentiful the present season than it has been at any time since 

 1887, and judging by the large numbers of moths that appeared at lights 

 during August and September, there must have been quite extensive 

 injuries from them. 



The Wheat-head Army Worm. — Attention has been called to this 

 species, Leucania albilinea, in nearly every report during the pa-st few 

 years, but it has this season appeared more numerously and attracted 

 more attention than at any time since the year 1887, and the distribu- 

 tion of the species in the State has been different from its occurrence 

 in previous seasons. The greatest amount of injury, judging from 

 reports, has been in the northeastern quarter of the State, particularly 

 in the line of counties running west from Dubuque to the middle of the 

 State. 



As in previous years, the reports have been in regard to injury to 

 timothy, and in no case have 1 learned of attacks upon wheat or other 

 crops, although it is not at all improbable that such crops have been 

 attacked, but injury has not been noticed. As the species has not been 

 abundant in the immediate vicinity of Ames, I have had no opportu- 

 nity to make direct investigations or to attempt immediate measures. 

 The varied food plant of the species, and particularly its inconspicuous 

 nature during the autumn months, make it difficult to suggest remedies 

 that are in any great degree successful or which could be considered 

 worthy of strong recommendation. In general, the recommendation has 

 been given that as soon as the injury is manifest upon timothy, and if 

 the worms are present in any considerable numbers, that the timothy 

 be cut immediately and saved for hay, since delay in the matter 

 would mean a loss of the seed crop and also loss of the hay. Even 

 at the time the worm becomes apparent in its stripping of the timothy 

 heads the hay is usually past its prime for forming the hay crop, but 

 it is much more profitable to save it then than to lose it entirely. This 

 method would, of course, be inapplicable in wheat fields, but, as already 

 stated, the injury from this species to the wheat in this section has not 

 at any time seemed serious. It is probable that the maintenance of 

 trap lights at the proper time would be quite effective, but the diffi- 

 culty of getting farmers to make use of any measures except at the 

 time when the damage is apparent, renders this of little avail. 



