DefinePK

Research Objective

To evaluate the efficacy of seed extracts from indigenous plants, specifically Moringa oleifera and Citrullus colocynthis, using methanol and water as solvents, against fungus-growing subterranean termites, assessing their impact on termite mortality, repellency, and foraging behavior.

Methodology

Seed extracts of Citrullus colocynthis and Moringa oleifera were prepared using methanol and water. Crude extracts were obtained by soaking shade-dried, ground seeds in the respective solvents, followed by filtration and evaporation. Bioassays were conducted in Petri dishes containing sterilized soil and sugarcane strips. Treatments included extract concentrations of 0% (control), 10%, 20%, and 40%, replicated three times. Thirty workers and five soldiers were introduced into each dish. Termite mortality was recorded at 2-hour intervals for 12 hours, then every 12 hours until all termites died. Tunnel formation was assessed by measuring the length of galleries constructed by termites at 5, 10, and 15-hour intervals. Probit analysis was used for toxicological assessment.

Methodology Flowchart

                        graph TD
    A[Collection of Termites and Plant Seeds] --> B[Preparation of Seed Extracts: Aqueous and Methanolic]
    B --> C[Preparation of Extract Solutions at Different Concentrations0%, 10%, 20%, 40%]
    C --> D[Bioassay Setup in Petri Dishes with Soil]
    D --> E[Introduction of Termites]
    E --> F[Monitoring Termite Mortality at Intervals]
    E --> G[Monitoring Tunnel Formation at Intervals]
    F --> H[Probit Analysis for Toxicological Assessment]
    G --> I[Measurement of Tunnel Lengths]
    H --> J[Analysis of Mortality Data]
    I --> K[Analysis of Tunneling Data]
    J --> L[Comparison of Results]
    K --> L
    L --> M[Conclusion and Recommendations]                    

Discussion

The study confirms the termiticidal properties of C. colocynthis and M. oleifera seed extracts, aligning with previous research on plant-derived biopesticides. The observed differences in mortality and tunneling behavior between the two plant species and solvents highlight the potential for developing targeted termite control strategies. Methanolic extracts were more effective, likely due to better solubility of active compounds. The reduction in tunneling activity suggests repellent or antifeedant properties, which are crucial for integrated pest management.

Key Findings

Both C. colocynthis and M. oleifera seed extracts negatively impacted termite survival and repellency. C. colocynthis showed higher termite mortality and lower LT50 values compared to M. oleifera. M. oleifera extracts had a more significant effect on reducing tunneling behavior than C. colocynthis extracts. Methanolic extracts generally exhibited greater efficacy than aqueous extracts for both plant species.

Conclusion

Seed extracts of Citrullus colocynthis and Moringa oleifera demonstrate significant potential as effective and environmentally safer alternatives to synthetic pesticides for controlling fungus-growing subterranean termites. C. colocynthis showed superior lethality, while M. oleifera was more effective in inhibiting tunneling. These native plant extracts are recommended for incorporation into termite management strategies.

Fact Check

1. Termite Order: Termites are classified under the order Blattodea, not Hymenoptera (which includes ants). This is confirmed in the introduction.
2. LT50 Values: The study reports LT50 values for various concentrations and solvents. For example, the LT50 for C. colocynthis methanol extract at 40% concentration was 157.656 hours.
3. Tunneling Reduction: The highest concentration (40%) of C. colocynthis aqueous extract resulted in the least tunnel construction (57.00 mm after 15 hours), as shown in Table 3.

Mind Map