Repellent and fumigant activities of Eucalyptus globulus and Artemisia carvifolia essential oils against Solenopsis invicta.

The repellent and fumigant activities plant essential oils of Eucalyptus globulus Labill. and Artemisia carvifolia Buch.-Ham. ex Roxb. on red imported fire ants (RIFAs) Solenopsis invicta Buren (Hymenoptera Formicidae) were evaluated by using digging bioassay and feeding/climbing behavior tests. Oil of Eucalyptus and Artemisia (mugwort) showed significant repellency at 100 mg/kg. However, slight digging facilitation was observed at 1 mg/kg. The attack and feeding rates of RIFAs on Tenebrio molitor L. (Co- leoptera Tenebrionidae) daubed with 5 μl of the two essential oils were evaluated. Eucalyptus oil showed a complete repellent ef- fect and prevented RIFA attacks on T. molitor. The time for complete repellency was 16 h. Mugwort oil showed weaker results than Eucalyptus oil. The feeding ability of RIFAs treated with the two essential oils decreased. The feeding, attack, and climbing rates of RIFA were observed 30 min after fumigation with the essential oils. Eucalyptus oil showed a greater effect on the climb- ing rate of RIFAs than mugwort oil. The feeding and attack rates after fumigation with the two essential oils were significantly lower than the control. Eucalyptus and mugwort oils could be used as alternatives to commercial repellents and fumigants.