2 BULLETIN 421, U. S. DEPARTMENT OF AGRICULTURE. 
HISTORY. 
The sugar-beet thrips was first described by Prof. O. M Renter (l), 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 Heliothrips 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 nocturnum 
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 in 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, 111.; 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 Rio Piedras, Porto Rico, on sugar cane, by Mr. Thomas H. 
Jones (Hood, 16). 
FOOD PLANTS. 
The sugar-beet thrips has confined itself chiefly to plants grown in 
the greenhouse, but it has been taken out of doors on sugar beets 
(Beta) and sugar cane (Saccharum officinarum). Hinds in 1902 listed 
the following food plants: Amaryllis sp., Aralia, calla (Arum), the 
night-blooming Jessamine {Oestrum nocturnum), Chrysanthemum, 
Crinum, cucumber (Cucumis), Dracaena, Amazon lily (EucJiaris 
grandiflora) , India-rubber tree (Ficus elastica), F. grandiflora, Gar- 
denia, cotton (Gossypium), Hydrangea, Mina lobata, moon flower 
(Ipomoea bonanot), screw pine (Pandanus), date palm (Phoenix), 
1 Figures in parentheses refer to Bibliography, p. 11. 
