In total, 29 compounds from sweet wormwood (
Artemisia annua
L.) oil were identified using gas chromatography–mass spectrometry. The five active components were
d
-camphor, linalool, cineole, α-terpineol, and
l
(−)-borneol. The effectiveness of
A. annua
oil, as well as
d
-camphor, linalool, cineole, α-terpineol, and
l
(−)-borneol, as fumigants, contact insecticides, and repellents, were tested on the red imported fire ant
Solenopsis invicta
Buren. The results indicated that
A. annua
oil has no significant topical toxicity; however, the spray contact test revealed that it has strong insecticidal activity and the inhibitory effect is stronger during closed exposure than during open exposure. In the fumigant test, cineole and
d
-camphor exhibited strong fumigant toxicity on minor and major
S. invicta
workers. They also caused 100% mortality at 5, 3, 2, and 1 mg/centrifuge tube but not at 0.5 mg/centrifuge tube. The mortality rates of linalool, α-terpineol, and
l
(−)-borneol exceeded 80% at 5, 3, and 2 mg/centrifuge tube. In the repellent test, cineole and
d
-camphor showed significant repellency at 100, 10, and 1 mg/kg. However, linalool, α-terpineol, and
l
(−)-borneol significantly facilitated digging at 10 and 1 mg/kg.
