by Caucasian tribes and in Persia to control body
lice. The flowers were first produced commercially
in Armenia in 1828. Production started in Dalmatia
(Yugoslavia) about 1840 and was centered there until
the first World War, in Japan until shortly before the
second World War, and in East Africa since then.
More than half of the world's current production
comes from Kenya, with important amounts from
Tanzania, Rwanda, and Ecuador. Insect powder was
first imported into the United States in about 1860,
and several unsuccessful attempts were made over
the next 90 years to produce the flowers commercially
in this country. Since about 60 years ago the
flowers were extracted with kerosene or similar solvents
to give liquid sprays more effective than the
powders.