No. 115.] 129 



The Acarina, or mites, have not been made a special study in 

 this country, and tor that reason comparatively little is known of 

 our species. Prof. Riley has described several species which are 

 parasitic on other insects, and others have been described and 

 illustrated by Dr. Packard in the American Naturalist, and else- 

 where. Recently Prof. Herbert Osborn, of the Iowa Agricultural 

 College, has taken up their study, and we hope soon to know more 

 of these minute but interesting and often quite injurious creatures. 

 In the Canadian Entomologist of the present year, Prof. Osborn, 

 in connection with Prof. Underwood, of the Syracuse University, 

 has given a " Preliminary List of Acarina of North America." 

 Ninety-nine species are recorded in the list, and their literature 

 given. 



The common " red spider," which is such a serious pest to gar- 

 deners, and especially obnoxious in the green-house, is a mite, 

 known scientifically as Tetranychus telarius Many of the species 

 of this genus are quite injurious to plants, shrubs, and trees. The 

 " lice " that infest canary birds are also mites, known as Dermanys- 

 sus avium. Other examples are the cheese mite, the itch mite, the 

 sugar mite, the " jigger " of the South, etc. 



Many of our species are identical with those of Europe, and have 

 probably been introduced from thence. 



Not being able to find any notice among our writers of a mite 

 injurious to grass, some of the examples above referred to were 

 sent to Dr. Hagen, of the Cambridge Museum, for such information as 

 he might give of them, he having at his command, in the exten- 

 sive entomological library of the museum nearly all the foreign 

 literature upon the subject. The mites were dead and dried when 

 received, and consequently in very unfit condition for study ; but 

 after undergoing maceration for two days, Dr. Hagen was able 

 to send me the following information in regard to them : 



" This species is very similar to Trombidium bicolor (Hermann, 

 Mem. Apteres, p. 25, pi. 2, f. 2); and Koch (Fasc. 151, No. 28), 

 from Alsace and Germany. The only related species would be 

 Trom. assimile (Koch, ibid, No. 19), but, after all, the species 

 seems to be T. bicolor, or very near to it. I do not know if these 

 species have since been put in another genus, perhaps in Tetrany- 

 chus ; the claws agree, but the legs are six-jointed." 



[Assembly, No. 115.] 9 



