Fumigant toxicity and behavioral inhibition of garlic against red imported fire ants (Solenopsis invicta)

In order to control the Solenopsis invicta (S. invicta) in a safe and ecofriendly manner, this study evaluated the fumigating activity of garlic and its effect on the behavior of S. invicta. The volatile compounds and chemical constituents from garlic were collected by solid phase micro-extraction and identified by gas chromatography-mass spectrometry (GC-MS). The results showed that garlic contains 21 compounds, and that diallyl disulfide (46.51%) and (E)-1-Allyl-2-(prop-1-en-1-yl) disulfane (34.68%) were the main constituents in garlic. In addition, garlic showed strong fumigant activity and behavioral inhibition against workers. The LC50 values of diallyl disulfide and methyl allyl disulfide against S. invicta at 12 h were 0.05 and 0.07 mu g/L, respectively. The grasping and walking abilities of ants were significantly suppressed. Moreover, minor workers were more susceptible than major workers. Thus, S. invicta can be controlled with garlic and some of its compounds as an eco-friendly approach. Results from the study could provide valuable advances for future fumigant development and possible utility in fumigant use.