|WANG, LEI - South China Agricultural University|
Submitted to: Journal of Chemical Ecology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/12/2015
Publication Date: 8/8/2015
Publication URL: http://handle.nal.usda.gov/10113/61870
Citation: Wang, L., Chen, J. 2015. Fatty amines from little black ants, Monomorium minimum, and their biological activities against red imported fire ants, Solenopsis invicta. Journal of Chemical Ecology. 41:708-715.
Interpretive Summary: The red imported fire ant is one of most notorious pest ants, causing significant ecological and economic impact. Little black ant is one of few native ants that can compete with imported fire ants. Defensive secretion often plays an important role in determining the outcome of competition among ants. Study on the chemistry of defensive secretion in little black ants may help us identify new fire ant toxins which are potentially useful in managing fire ants. In this study, we analyzed defensive secretion of workers and queens of little black ants and revealed the presence of two fatty primary amines, decylamine and dodecylamine. Both amines have never been reported from any natural sources. Both compounds showed toxicity and repellency against red imported fire ants. Those compounds may be potentially useful in developing new products for controlling imported fire ants.
Technical Abstract: Chemistry of defensive sections in the genus Monomorium has been subjected to rigorous research. The venom of little black ants, Monomorium minimum, has been reported to be dominated by insecticidal alkaloids including 2,5-dialkypyrrolidines and 2,5-dialkypyrrolines. In this study, analysis of defensive secretion of workers and queens of M. minimum revealed the presence of two fatty primary amines, decylamine and dodecylamine. Both amines have never been reported from any natural sources. It has been reported that M. minimum can compete with the red imported fire ants, Solenopsis invicta, one of the most invasive ant species in the world. Chemical interference is important in competition between these two ant species. Decylamine showed higher toxicity and repellency against S. invicta workers than dodecylamine. LD50 value ranged from 23.54 to 24.81 µg ant-1 for decylamine and 62.65 to 68.38 µg ant-1 for dodecylamine. Decylamine also showed quicker knockdown effect than dodecylamine. At a dose of 92.80 µg ant-1, the KT50 value for workers ranges from 8.24 to 9.50 min for decylamine and 29.86 to 33.46 min for dodecylamine. At 100 ppm, decylamine completely suppressed the digging behavior of S. workers; whereas, dodecylamine caused complete suppression of digging behavior for 2 of 3 colonies at 200 ppm. In addition to 2,5-dialkyl-pyrrolidines and 2,5-dialkyl-pyrrolines, these two fatty amines may play a role in chemical defense of M. minimum.