38 



Auo-ust 2, 1900, its occurrence on Ajnos tuherosa was reported by 

 the late Thomas A. Williams, of this Department. 



Violets and carnations were seriously injured during- the last two 

 years in the District of Columbia, and we received in a letter dated 

 March 19, 1901, information concerning general destructiveness by 

 this species to straw])err3' in the vicinity to Galloway. Polk County, 

 Fla. Our correspondent, Mr. E. G. Gardner, stated that the mites 

 were always found on the underside of the leaves. 



IDENTITY OF THK SPECIES; EITERATURE. 



The subject of the specitic identilications of the different species of 

 red spiders which occur in this country , of which there are 11 distinct 

 forms described, together with the characteristics which distinguish 

 them, and other information of more or less technical import, has been 

 already made public in a paper entitled "The Red Spiders of the 

 United States," Ijy Mr. Nathan Banks, published on pages G5-TT of 

 Technical Scries No. 8 of this Division. 



Tetramjchus hliiiaculdtus was tirst described b}' the late Prof. F. L. 

 Harvey in 1893 (Annual Report Maine State College Agr, Exp. Sta- 

 tion, Part IV, pp. 138-11:1:, pi. 3). This account includes valuable 

 notes on the insect's habits and injuries, a tal)ulated list of host plants, 

 extracts from correspondence, and a consideration of remedies, besides 

 technical descriptions of the diti'erent stages of the species. 



In Galloway's Coumiercial Violet Culture, already quoted, consider- 

 able space is devoted to a consideration of this specise, mentioned as 

 " red spider" (pp. 190-198), particular attention being given to remedial 

 treatment l)ased upon years of experience with it as it occurs on 

 violets grown under glass. 



The al)ove-mentioned pu])lications have been freely used in \\\*^ prep- 

 aration of the present article. 



The species has l)een treated from the standpoint of an enemv of 

 sugar beets, with l)rief mention of its occurrenc-e on hemp near Tre- 

 mont and Pekin, 111., in 1899 and l!>00, on pages 106 and lo7 of Bulletin 

 No. 00 of the University of Illinois Agricultural Experiment Station, 

 b}" Messrs. Forl)es and Hart. 



FOOD PLANTS AND NATURE OF IN.TURY. 



The two-spotted red spider is inclined to be omnivorous, attacking 

 a wide range of l)oth glabrous and hirsute plants belonging to several 

 families. It is present in greenhouses throughout the year, and appears 

 to l)e able at all times to be destructive if permitted to propagate. 

 Few plants are, in fact, free from the attack of this red spider, and it 

 is present in most greenhouses. When onh' a few mites are present, 

 the plants seldom show anv external evidences of injur}', ))ut as they 



