DefinePK hosts the largest index of Pakistani journals, research articles, news headlines, and videos. It also offers chapter-level book search.
Title: Evaluation of Plant Essential Oils against Sitophilus oryzae Linnaeus (Coleoptera: Curculionidae) under Laboratory Conditions
Authors: Khadija Rajput, Arfan Ahmed Gilal, Lubna Bashir Rajput, Jamal-U-Ddin Hajano, Safia Magsi, Jam Ghulam Mustafa Sahto, Zakia Panhwar, Ghulam Hussain Jatoi
Journal: Plant Protection
Publisher: Center for Community Learning
Country: Pakistan
Year: 2023
Volume: 7
Issue: 3
Language: English
Keywords: riceMortalityBotanicalInsecticidalRepellenceWeevil
Sitophilus oryzae Linnaeus, commonly known as rice weevil is a globally serious pest of stored grains, especially rice. Considering the target specific nature of botanicals and less hazardous effect than synthetic insecticides, the study was conducted to evaluate the effectiveness and appropriate dosage of four essential oils i.e., lemongrass ( Cymbopogon citratus Stap.), eucalyptus ( Eucalyptus globulus Labill.), peppermint ( Mentha piperita L.), and tea tree ( Melaleuca alternifolia L.) against S. oryzae. Each essential oil was used at 0.1, 0.5, and 1.0 ml doses on filter paper. A long glass cylinder (1000 ml size), divided into three (A, B, and C) sections, supplied with 20 g rice at ends, was used in the study. Ten freshly emerged adults of S. oryzae were released in the center of B, whereas treated and untreated filter paper was placed at A and C section, respectively. Observations on repellency and mortality percentage were recorded after 24 and 48 hours of exposure. The results indicated that all the tested essential oils exhibited insecticidal potential against S. oryzae . The insecticidal activity of all the essential oils increased with their application dose and exposure timing. Maximum mortality of S. oryzae after 48 hours was recorded in tea tree (76.67±3.33%) at 1.0 ml dose, whereas maximum repellency was recorded with 0.1 ml lemongrass (76.67±12.02%) treatment. Overall, tea tree and lemongrass showed maximum insecticidal performance, whereas peppermint was the least effective. After 48 hours, the lowest [0.008 ml (0.001-0.019) and highest [0.018 ml (0.000-0.078) LD 50 values against S. oryzae were recorded with lemongrass and peppermint essential oils, respectively. The LD 50 values recorded for eucalyptus and tea tree treatment were 0.07 ml (0.000-0.059) and 0.009 ml (0.000-0.046), respectively. Therefore, it is suggested that the essential oils of either tea tree or lemongrass may be applied in the warehouses against S. oryzae , that may not only cause repellency but also mortality among them.
To evaluate the effectiveness and appropriate dosage of four essential oils (lemongrass, eucalyptus, peppermint, and tea tree) against the rice weevil, Sitophilus oryzae, under laboratory conditions.
The study involved testing four essential oils (lemongrass, eucalyptus, peppermint, and tea tree) at three different doses (0.1, 0.5, and 1.0 ml) against Sitophilus oryzae. A long glass cylinder divided into three sections was used, with rice placed at the ends and 20 freshly emerged adult rice weevils released in the center. Treated and untreated filter papers were placed in adjacent sections. Observations on repellency and mortality were recorded after 24 and 48 hours. Analysis of Variance (ANOVA) and Least Square Difference (LSD) were used for statistical analysis, and Probit Analysis was employed to calculate LD50 values.
graph TD
A[Select Essential Oils and Doses] --> B[Prepare Experimental Setup];
B --> C[Release Sitophilus oryzae Adults];
C --> D[Apply Treated/Untreated Filter Paper];
D --> E[Record ObservationsRepellency & Mortality];
E --> F[Analyze DataANOVA, LSD, Probit];
F --> G[Determine LD50 Values];
G --> H[Draw Conclusions and Recommendations];
The study supports previous research on botanical pesticides, indicating that essential oils of tea tree and lemongrass are effective against stored grain pests like S. oryzae. The findings suggest that these oils can be used as environmentally friendly alternatives to synthetic insecticides. The increased insecticidal activity with higher doses and longer exposure times is consistent with other studies. The repellent properties of some oils, like peppermint and eucalyptus, are also highlighted as a valuable aspect of their pest management potential.
All tested essential oils exhibited insecticidal potential against S. oryzae, with activity increasing with dose and exposure time. Tea tree essential oil at 1.0 ml dose showed maximum mortality (76.67±3.33%) after 48 hours. Lemongrass essential oil at 0.1 ml dose exhibited maximum repellency (76.67±12.02%) after 48 hours. Tea tree and lemongrass oils demonstrated the best overall insecticidal performance, while peppermint was the least effective in terms of mortality but showed good repellent potential. The lowest LD50 values were recorded for lemongrass and tea tree essential oils.
Essential oils of tea tree and lemongrass are effective against Sitophilus oryzae, showing significant mortality and repellency. Their insecticidal potential increases with dosage and exposure time. These oils can be recommended for large-scale application in warehouses to manage rice weevil infestations and reduce losses to cereals.
1. Maximum Mortality: Tea tree essential oil at a 1.0 ml dose resulted in a maximum mortality of 76.67±3.33% against S. oryzae after 48 hours.
2. Maximum Repellency: Lemongrass essential oil at a 0.1 ml dose resulted in maximum repellency of 76.67±12.02% against S. oryzae after 48 hours.
3. Lowest LD50: Lemongrass essential oil showed the lowest LD50 value of 0.008 ml after 48 hours.
Loading PDF...
Loading Statistics...