2 BULLETIN 421, U. S. DEPARTMENT OF AGEICULTUKE. 



HISTORY. 



The sugar-beet thrips was first described by Prof. O. M Reuter (1)/ 

 from specimens taken in the greenhouse in 1891, at Helsingfors, 

 Finland. The first record we have of its occurrence in the United 

 States was made by Mr. Theo. Pergande (2), who described it in 1895 

 as Eelioihrips cestri n. sp., and wrote that it had been known to him 

 since 1884, at which time specimens were presented by Mr. P. B. 

 Mann, who discovered them infesting a plant of Oestrum nodurnum 

 from Massachusetts. He also stated that about the same time it 

 was sent to him from Helsingfors, Finland; and that in 1883 he 

 discovered the same species, extremely abundant on leaves of an 

 amaryUis, in a conservatory of the Department of Agriculture at 

 Washington, D. C. It was redescribed by Uzel in 1895 (3), and 

 again by Hinds in 1902 (6). Since that time we have brief records 

 of its occurrence in many localities m the United States and elsewhere. 



DISTRIBUTION. * 



The sugar-beet thrips is widely distributed and is found principally 

 in greenhouses. It is recorded as occurring in greenhouses in the 

 British Isles, Italy, Belgium, Austria, Finland, German East Africa, 

 Sweden, and Spain. 



It is also well distributed over the United States, and is reported 

 from the District of Columbia; Lacrosse, Wis.; Ithaca, N. Y.; 

 Vienna, Va.; Urbana, lU.; Champaign, 111.; Lincoln, Nebr.; and 

 Amherst, Mass. 



The first observation which we have of its occurrence on sugar 

 beets and out of doors was made by Dr. F. H. Chittenden (7), who 

 collected specimens at Washington, D. C, on August 15, 1904. He 

 also observed it on greenhouse sugar beets. In 1907 it was collected 

 on sugar beet at Hamilton City, Cal., by Prof. E. S. G. Titus, and in 

 1914 from Pio Piedras, Porto Pico, on sugar cane, by Mr. Thomas H. 

 Jones (Hood, 16). 



FOOD PLANTS. 



The sugar-beet thrips has confined itseK chiefly to plants grown in 

 the greenhouse, but it has been taken out of doors on sugar beets 

 (Beta) and sugar cane {Saccharum ojicinarum). Hinds in 1902 Hsted 

 the following food plants: Amaryllis sp., Aralia, calla (Arum), the 

 night-blooming Jessamine {Oestrum nodurnum), Chrysanthemum, 

 Crinum, cucumber (Cucumis), Dracaena, Amazon lily (EucTiaris 

 grandiflora) , India-rubber tree (Ficus elastica), F. grandijlora, Gar- 

 denia, cotton (Gossypium), Hydrangea, Mina lobata, moon flower 

 {Ifomoea honanot), screw pine (Pandanus), date palm (Phoenix), 



1 Figures in parentheses refer to Bibliography, p. IL 



