2 
value at least 50 per cent. The expense in grading is also largely 
increased. When we consider that the tobacco thus injured is the high- 
est grade grown in this country, it will be seen that the loss thus occa- 
sioned is a large one. 
The adult tobacco thrips (fig. 2) appear to pass the winter in the tobacco 
fields. They were found in the fields when first visited, the middle of 
April, feeding upon the young cocklebur, the principal weed. From the 
weeds they spread to the tobacco plants when the latter were trans- 
planted. They first appear upon the lower leaves, from which they 
spread to the leaves above, the lower leaves thus being the worst 
affected. 
The eggs are deposited in tissues of the stem and leaves. On hatch- 
ing, the larvee feed largely on the lower surface of the leaves, but as 
they reach the adult 
stage seem to prefer 
the upper surface, 
and this habit is 
taken advantage of 
in remedial  treat- 
ment. The life cycle 
is passed in twelve or 
thirteen days. By 
this rapid reproduc- 
tion from the com- 
paratively few that 
pass the winter suc- 
cessfully, they soon 
i) reach vast numbers 
Fig.2.—Euthrips nicotiane: Adult insect, much enlarged (original). an ad ebiacomic tine 
source of extensive injury. After the tobacco is harvested the thrips 
live on the weeds in the field until cold weather drives them into 
hibernation. 
REMEDIES. 
Remedies may be considered under two heads, namely, cultural 
methods and insecticide applications. 
CULTURAL METHODS. 
The practice of locating the seed bed in the tobacco field is a bad 
one, as it furnishes a breeding place from which to spread into the field, 
not only for thrips, but for other pests, flea-beetles especially. When 
necessary so to locate the seed bed, frequent applications of kerosene 
emulsion, as herein described, and arsenicals, should be made. 
At present it would seem advisable that clean culture be practiced 
between crops. It may be found, however, that kerosene emulsion will 
sufficiently control the pest, in which case catch crops may be grown. 
