MOLLUSCICIDAL ACTIVITY OF Entada rheedii STEM BARK METHANOLIC EXTRACT AGAINST PADDY PEST Pomacea canaliculata (GOLDEN APPLE SNAIL)

Abstract

The study was conducted to evaluate the molluscicidal activity of E. rheedii methanol bark extract against P. canaliculata and to screen for phytochemical compounds of E. rheedii bark extracts. The golden apple snails with size range of 20 -40 mm were treated with four different concentrations of E. rheedii (1000, 5000, 10000 and 20000 ppm) and paddy-field water mix with 50% methanol serving as the control treatment. The molluscicidal effects of the extract were evaluated after 24, 48 and 72 hours. The results of the study showed that high treatment concentrations (10000 and 20000 ppm) recorded the highest mortality rate (100%) while low concentrations (1000 ppm) showed the lowest mortality rate (27%). However, no mortality was recorded in the control treatment. The molluscicides activity with LC 50 is 1,611 ppm and LC 90 is 4,266 ppm and could be attributed to the presence of saponin in the bark extracts. E. rheedii bark extract provides a great potential for developing green pesticides to control P. canaliculata. Nevertheless, further research is needed to determine its biochemical mechanism.Keywords: golden apple snail, Entada rheedii, molluscicidal activity, phytochemical content Abstrak Kajian ini dijalankan untuk menilai aktiviti moluskisida oleh ekstrak metanol kulit kayu E. rheedii terhadap P. canaliculata dan untuk menyaring sebatian fitokimia yang terkandung di dalam ekstrak kulit kayu E. rheedii. Siput gondang emas bersaiz antara 20 -40 mm telah dirawat dengan empat kepekatan E. rheedii yang berbeza (1000, 5000, 10000 dan 20000 ppm) dan campuran air sawah padi dengan 50% metanol menjadi rawatan kawalan. Kesan moluskisida oleh ekstrak dinilai selepas 24, 48 dan 72 jam. Keputusan kajian menunjukkan bahawa kepekatan rawatan tinggi (10000 dan 20000 ppm) mencatatkan kadar kematian tertinggi (100%) manakala kepekatan yang rendah (1000 ppm) menunjukkan kadar kematian yang paling rendah (27%). Walau bagaimanapun, tiada kematian direkodkan dalam rawatan kawalan. Aktiviti moluskisida dengan LC 50 adalah 1611 ppm dan LC 90 adalah 4266 ppm boleh dikaitkan dengan kehadiran saponin dalam ekstrak kulit kayu. Ekstrak kulit kayu E. rheedii mempunyai potensi yang besar dalam membangunkan racun perosak yang selamat terhadap alam sekitar untuk mengawal P. canaliculata. Walau bagaimanapun, penyelidikan lanjut perlu dilakukan untuk menentukan mekanisme biokimianya.Kata kunci: siput gondang emas, Entada rheedii, aktiviti moluskisida, kandungan fitokimia

THE MOLLUSCICIDAL EFFECT OF THE STEM EXTRACTS OF Tinospora crispa IN CONTROLLING THE GOLDEN APPLE SNAIL Pomacea canaliculata

“…A total of 200 adult snails (18 -25 mm) were collected from the paddy field in Pekan, Pahang, Malaysia. They were acclimatized to the laboratory environment (25℃) for three days and fed with papaya leaves [15,16], after which snails were randomly selected for the molluscicidal study.…”

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“…Golden Apple Snails (GAS) or commonly known as Siput Gondang Emas is a large freshwater snail that is native to tropical and subtropical South America (Liu et al 2018). In 1987, GAS (Mollusca: Ampullariidae: Pomacea canaliculata) was introduced in Malaysia as a food item and aquarium pet, but now it is one of the most serious pests that caused extreme damage to paddy fields (Nur Suraya, Noorshilawati & Rosminah 2017). Yahaya et al (2017) reported that GAS is highly invasive and caused a drastic reduction in the production of rice in ASEAN countries, especially in Malaysia causing losses amounting to RM82 million in 2010.…”