140 



the writer in heads of Timothy grass in Iowa, and next recorded by 

 Lindeman as living on the same and other plants at Moscow. 



Aptinothrlps rufa Hal., he states to subsist upon grasses and compo- 

 sitne. 



Fhlceothrips armata Lindeman, is a new species that he describes as 

 affecting Anthemis tinctoria, Chrysanthemum leucanthemum^ and other 

 plants. 



Professor Lintner included Limothrips [Thrips) tritici Fitch in his lists 

 of clover insects (Report of ^ew York Agricultural Society for 1881-82, 

 p. 192), and also mentions a " Thrips sp." in the same connection. 



In Prof. W. J. Beal's Grasses of North America, Professor Cook, in 

 chapter on insects, page 375, says of Thripidte : 



The past season I have found three species, one black, one light yellow, and one 

 bright red, all to be very abundant on the clover blossoms, yet I could not see that 

 they were greatly injurious. 



Further, page 401 of same work, in regard to grass withering in sum- 

 mer : 



This is more hkely due to species of Thrips, three of which I have taken from the 

 culms. . 



Professor Cook also informs me that Professor Fernald has described 

 the attacks of one species on grass, but I have not the reference at hand ; 

 and also that he has dissected Thripidse, and found their stomachs to 

 contain grains of pollen. 



The species referred to as attacking grass may very likely be the 

 same as credited with destroying grass by Professor Comstock, and 

 given the manuscript name of Limothrips poaphagus. 



Since presenting the statements in my paper published in 1883 I 

 have watched every season the work of the common species at Ames, | 

 and especially in clover heads have noted the operations of thousands 

 of individuals. In all these observations I have not seen a single example 

 of Cecidomyia larva or anything to indicate attack upon these or any 

 other insects. On the contrary', as recorded in my report to Professor 

 Riley for 1887 (Rep. Dep. Ag., 1887), I have seen theThripida? fall a prey 

 to the Insidious Flower Bug [ThriphJeps insUliosus). I feel pretty well 

 convinced, therefore, that whatever they may do when Cecidomyia larv?e 

 are present, they must be able to live without them, and it seems almost 

 certain that they subsist upon the tissues of the clover itself, since they 

 occur in all stages of development. I have also observed a species re- 

 sembling tritici in Wild Morning-glory blossoms, Fitch's FhlocothripB 

 mail on grape leaves, and what is presumably his Coleoihrips trifasciata 

 (though my specimens differ in certain characters given generic impor- 

 tance) on a common weed, and in none of these species liave I seen 1] 

 evidence of feeding upon anything but the plant or its secretions. Last 

 summer (1887) I collected an undescribed species from the leaves of hop 

 in AVisconsin. Individuals of various sizes, mostly larvfe, being found 

 more or less clustered together on the leaves, and there seemed to be 



