SB 
818 i 
C578 fee 68. 
ENT tited States Department of Agriculture, » 
BUREAU OF ENTOMOLOGY, 
L. O. HOWARD, Entomologist. 
THE TOBACCO THRIPS AND REMEDIES TO PREVENT “WHITE VEINS” 
IN WRAPPER TOBACCO. 
(Huthrips nicotiane Hinds.)! 
By W. A. Hooker, Special Wield Agent. 
In the tobacco thrips, an insect until recently unknown to science, 
we have a pest that has become of great economic importance. It is 
closely related to the minute yel- 
lowish wheat thrips (Huthrips 
tritici Fitch) that is common 
everywhere in blossoms of all 
kinds. It may be distinguished, 
however, by its brown color. 
The common onion thrips 
(Thrips tabaci) of this country 
was originally described by 
Lindeman as attacking tobacco 
in Russia, but since it has never 
been found to do so in the United 
States, this new pest may be 
termed “the tobacco thrips.”’ 
This insect injures’ shade- 
grown cigar-wrapper tobacco in 
Florida, southern Georgia, and 
Texas, and thus appears to be 
widely distributed through the 
South. Its occurrence in Texas 
was discovered the past sum- 
mer. The adult thrips in feed- 
ing on the upper surface of the 
leaves, as is their custom, re- 
move the sap from the lateral 
veins and veinlets, which when 
fermented and ready for the 
trade become of a much lighter color than the other parts of the leaf. 
These light veins (fig. 1) are objectionable, since they appear in the 
manufactured cigars. As a result, tobacco thus affected is reduced in 
‘ 
Fig. 1.—Leaf of tobacco, showing “ white veins ”’ 
eaused by Euthrips nicotiane (original). 
1 Described in the Proceedings of the Biological Society of Washington, Vol. 
XVIII, pp. 197-200, September, 1905. ; 
