Efficacy of Indigenous Crude Plant Extracts against Rice Weevil, Sitophilus oryzae L. 1763 (Coleoptera: Curculionidae)

Abstract

Rice weevil, Sitophilus oryzae L. (Coleoptera: Curculionidae) is a widely distributed and major insect pest of rice that causes considerable losses to both husked and unhusked rice grains. Plant-based pesticides are alternative to synthetic pesticides in managing stored product pests owing to their severe hazardous effects. Thus, locally available plant leaf crude extracts i.e., neem (Azadirachta indica A. Juss 1830), turmeric (Curcuma longa L. 1753), and mint (Mentha longifolia L. Huds. 1762) were investigated at 2 % (w/w) concentration against S. oryzae in unhusked and husked rice. Adult mortality was recorded at 24, 48 hours, and seven days after the application whereas, population build-up was recorded at 1-, 2-, and 3-months intervals. Overall and grain weight loss was also recorded at the end of the experiment. In husked and unhusked rice, the highest mortality percentage was observed in turmeric powder (93.30 %) and neem (80.00 %), respectively. In comparison to plant extracts, relatively higher population growth of S. oryzae was recorded in control husked and unhusked rice. At the end of the 3rd month, the highest and lowest population in husked rice grains was recorded in control (70.67 ± 3.18) and turmeric treatments (18.00 ± 2.65), respectively, whereas control and neem treatments exhibited the highest (83.67 ± 3.28) and lowest (39.67 ± 2.33) populations in unhusked rice. The lowest grain weight loss in husked and unhusked rice was recorded in turmeric (9.33 %) and neem (16.67 %), respectively. Thus, turmeric and neem extracts should be investigated on large scale under commercial warehouses for the management of S. oryzae in husked and unhusked rice.

Mediterranean Plants as Potential Source of Biopesticides: An Overview of Current Research and Future Trends

“…The applied protocol was based on transferring third-instar larvae of the fly in glass vials with filter papers impregnated with different dilutions of the essential oils [ 153 ]. Various residual or surface contact bioassays, with certain modifications in their protocols, were used to test the bioactivity of a variety of plant extracts and essential oils against eggs, larvae, and adult specimens of insects and mites [ 70 , 72 , 74 , 82 , 87 , 89 , 90 , 92 , 98 , 102 , 113 , 130 , 147 , 148 , 150 , 154 , 155 , 156 , 157 , 158 , 159 ]. For instance, Erdogan and Mustafa dipped tomato leaf discs into the test solutions instead of pipetting a volume onto their surface and then placed Tuta absoluta larvae on them [ 92 ].…”

Impacto de Azadirachta indica sobre la población de insectos en un cultivo experimental de arroz

“…El efecto del extracto de hojas de neem también ha sido evaluado sobre: hongos (Alternaria solani y Fusarium oxysporum), plantas de tomate (Hassanein et al, 2010), cultivo de arroz (Kamarulzaman et al, 2018), y contra Sitophilus oryzae (Imran et al, 2021). Se ha documentado que el neem inhibe la germinación y el crecimiento de varias especies vegetales: alfalfa (Medicago sativa L.), judía (Vigna angularis [Willd.]…”