148 REPORT OF THE DEPARTMENT OF BOTANY OF THE 
below. In such cases the leaf and sheath springing from the upper- 
most node are dead, dry and light colored like the panicle. 
This trouble of June grass is well known to entomologists.‘ In 
America it is often called “silver top”; and the cause of it is be- 
lieved to be some sucking insect, Anaphothrips striata Osb. being 
the particular species usually held responsible for it. However, 
some writers express the opinion that it may be brought about by 
any one of several species. Reuter, who made an exhaustive 
investigation of it in Finland, gave it the German name Weissah- 
rigkeit and attributed the greater part of it to certain species of 
mites. Hinds!® gives a list of 32 species of grasses which are more 
or less subject to silver top in Massachusetts. In New York, June 
grass is the species most conspicuously affected; although the 
“Some of the principal American articles on silver top and its causes are 
the following: 
Cary, Lewis R. The grass thrips (Anaphothrips striata Osborn). Me. 
Sta. Bul. 83. 1902. 
Comstock, J. H. Notes on entomology: A syllabus of a course of 
lectures delivered at the Cornell University, p. 120. Ithaca, N. Y. 
1875. 
The grass-eating thrips. Amer, Nat, 22: 260— 
261. 1888. 
—_—_—___—_—_——. An introduction to entomology, p. 127. Ithaca, 
Ney... 168s. 
Fernald, C. H. Grasses of Maine. Rpt. Sec. Me. Board of Agri- 
culture, for the year 1884, p. 233. 1885. 
Fernald, H. T. and Hinds, W. E. The grass thrips, Anaphothrips 
striata (Osb.). Hatch Exp. Sta. of the Mass. Ag. Coll.) Bul. 
67. 1900. 
Fletcher, Jas. Siver top of hay—An unknown enemy. Canada Expt. 
Farms Rpts. for 1888, pp. 59—62. 1889. 
Hinds, W. E. The grass thrips. Mass. Ag. Coll. Rpt. 37: 83— 
105. 1900. Contains bibliography. 
Lintner, J. A. An unknown grass pest. N. Y. State Mus. Nat. 
Hist. Rpt. 40: 96-08. 1887. 
N.Y... tate Mus. Nat.) Hist. Rots i cee 
1889. 
Osborn, H. Silver top in grass and the insects which may pro- 
duce it. Canad. Ent., 23: 93-96. 1801. 
Webster, F. M. Notes on some species of insects which affect the 
upper portion of the stems of some grasses. Insect Life, 1: 372- 
374. 1880. 
® Reuter, Enzio. Ueber die Weissahrigkeit der Wiesengraser in Finland. 
Ein Beitrag zur Kenntnis ihrer Ursachen. Acta Soc. pro Fauna et Flora 
Fennica, 19: No. 1, pp. 1-136. Helsingfors, 1900. Contains an extensive 
bibliography. (Abstract in Ztschr. Pflanzenkrank., 11: 250-253.) 
* Hinds. loc. cit., p. 94. 
