Effectiveness of Curcuma longa and Cymbopogon citratus Leaf Extracts as Botanical Pesticides for Controlling Golden Apple Snail, Pomacea canaliculata

Abstract

The golden apple snail (GAS), Pomacea canaliculata is a major pest that leads to decline in rice productivity in Malaysia. The farmers used of synthetic molluscicides on GAS in paddy fields resulted in negative impacts to the environment and human health. The botanical pesticide is a potential alternative way to combat GAS. This study is to reveal the effectiveness of Curcuma longa and Cymbopogon citratus extracts using the toxicity test and antifeedant activities. The leaves of C. longa and C. citratus were extracted using solvents, ethanol, and methanol. The extracts were tested on GAS for concentrations of 10–50 g/L. The time recorded for mortality of GAS was from 24 to 96 h. The results from toxicity test showed that methanol extract of C. citratus (LC50 = 30.503 g/L) gave higher mortality GAS compared to its’ ethanol extract (LC50 = 37.12 g/L). Meanwhile, higher antifeedant activities were imposed using ethanol extract of C. longa (LC50 = 32.475 g/L) compared to methanol extract of C. longa (LC50 = 42.042 g/L). The Salkowski test shows terpene compounds in C. longa and C. citratus extract. The study identifies C. citratus as more effective in controlling GAS and C. longa extracts have effects on antifeedant activity. Thus, C. longa and C. citratus extracts have potential to be used as botanical pesticides for controlling GAS.