Insecticidal potentials of plant powders against pests of stored grains; Sitophilus oryzae (rice weevil) and Callosobruchus maculatus (cowpea weevil) in Sri Lanka
| dc.contributor.author | Anuradha, G. N. P. V. | |
| dc.contributor.author | Rajapaksha, W. R. G. W. N. | |
| dc.contributor.author | de Silva, W. A. P. P. | |
| dc.contributor.author | Weeraratne, T. C. | |
| dc.date.accessioned | 2024-10-29T18:02:57Z | |
| dc.date.available | 2024-10-29T18:02:57Z | |
| dc.date.issued | 2024-11-01 | |
| dc.description.abstract | Due to the negative impacts of synthetic insecticides, there is a pressing need for alternative, eco-friendly approaches to control pests of stored grains. This study aimed to investigate the effectiveness of powders of Syzygium aromaticum leaves, Allium sativum cloves, and Olax zeylanica leaves against Sitophilus oryzae and Callosobruchus maculatus, pests of stored grains. Smooth plant powder was prepared by grinding the dried leaves/cloves. Hundred healthy adults of each pest species (25 per replicate) from laboratory stock cultures were exposed to five concentrations (1%, 2%, 4%, 6%, and 8% w/w) of each plant powder, mixed in 100 g of disinfected grains in plastic containers covered with muslin cloth, and mortalities were recorded after every 24 hrs until 12 days. Log-probit curves were constructed, and the lethal concentration (LC₅₀) and lethal time (LT₅₀) required to kill 50% of the population were obtained by regression analysis. When treated with ≥ 2% O. zeylanica, both S. oryzae and C. maculatus exhibited 100% mortality within 24 hrs, and the LT₅₀ values were 10 hrs and 8 hrs, respectively. Allium sativum and S. aromaticum treatments demonstrated relatively low toxicity, as indicated by their high LT₅₀ values, with 12 days required to achieve 100% mortality in both pest species. Although the toxicity effect between A. sativum and S. aromaticum against S. oryzae was not significant (p = 0.806), S. aromaticum showed higher toxicity against C. maculatus, with a LC₅₀ of 0.85% and a LT₅₀ of 1.4 days at 2%, compared to A. sativum, which had a LC₅₀ of 4.9% and a LT₅₀ of 3.4 days at 2%. However, 100% mortality of C. maculatus was observed within 24 hrs when a high concentration, i.e. 8%, was used. The overall results revealed an effective toxicity against both pests in the order of O. zeylanica > S. aromaticum > A. sativum. Further studies would explore the repellence and synergistic effects of these plant products for pest management. | |
| dc.description.sponsorship | Financial assistance from the PGIS Research Grant Programme 2020 (Grant No. PGIS/2020/12) is acknowledged | |
| dc.identifier.citation | Proceedings of the Postgraduate Institute of Science Research Congress (RESCON) -2024, University of Peradeniya, P 140 | |
| dc.identifier.issn | 3051-4622 | |
| dc.identifier.uri | https://ir.lib.pdn.ac.lk/handle/20.500.14444/2829 | |
| dc.language.iso | en | |
| dc.publisher | Postgraduate Institute of Science (PGIS), University of Peradeniya, Sri Lanka | |
| dc.relation.ispartofseries | Volume 11 | |
| dc.subject | Allium sativum | |
| dc.subject | Insect pest control | |
| dc.subject | Olax zeylanica | |
| dc.subject | Pests of stored grains | |
| dc.subject | Syzygium aromaticum | |
| dc.title | Insecticidal potentials of plant powders against pests of stored grains; Sitophilus oryzae (rice weevil) and Callosobruchus maculatus (cowpea weevil) in Sri Lanka | |
| dc.type | Article |