Invasive Species Compendium

Detailed coverage of invasive species threatening livelihoods and the environment worldwide

Abstract

Repellent and insecticidal activities of the root extracts of Chromolaena odorata and Mimosa diplotricha against Macrotermes species.

Abstract

Background and Objective: Although a number of studies have empirically evaluated the use of extracts from several indigenous plants against insect pests, but little is known about the use of extracts from invasive alien plants to control these noxious species. This study investigated the repellent and insecticidal activities of the root extracts of two invasive alien plants, Chromolaena odorata and Mimosa diplotricha against Macrotermes species. Materials and Methods: Four concentrations of the aqueous root extracts of the two plants were tested on the worker caste of Macrotermes species using the filter paper impregnation technique after which percentage repellency was monitored for 30 min. In a similar experimental setup mortality was monitored for 12, 24 and 36 h. Results: The highest concentration [10% (w/v)] of the root extracts of C. odorata and M. diplotricha significantly repelled 98 and 100% of Macrotermes species, respectively, following a 30 min exposure period. Mortality of Macrotermes species caused by the root extracts of C. odorata and M. diplotricha was high and observed to be concentration and exposure time dependent. The highest concentration [10% (w/v)] of C. odorata and M. diplotricha root extracts accounted for 100% mortality against Macrotermes species after a 36 h exposure period. Following a 36 h exposure period, the median lethal concentrations (LC50) of C. odorata and M. diplotricha against the termites were 1.72 and 4.12% (w/v), respectively. Conclusion: This study elucidates the repellent and insecticidal activities of the root extracts of C. odorata and M. diplotricha for the first time and suggests that the root extracts of both plants can be used for the control of Macrotermes species.