GCMS profiling and larvicidal potentials of the extracts of Terminalia catappa leaf, Eucalyptus citriodora seed and stem against malarial, dengue and filarial vector mosquitoes (Diptera: Culicidae)

Résumé

The worldwide proliferation of vector-borne infections, coupled with advancing insect defense mechanisms against standard synthetic pesticides, compels the exploration of ecological, vegetation-derived countermeasures. This investigation sought to characterize the secondary metabolite distribution, prominent chemical fractions, and destructive impact of Terminalia catappa leaf ethyl acetate extract (TLEE), alongside Eucalyptus citriodora stem ethyl acetate extract (LSEE) and seed ethyl acetate extract (LEEE), against Aedes aegypti , Anopheles gambiae , and Culex quinquefasciatus . Mild ambient maceration of the leaf, seed and stem parts generated yield allocations of 3.3% TLEE, 2.8% LSEE, and 4.7% LEEE. Standardized larval mortality challenges captured survival dynamics across a 125 to 1000 ppm exposure gradient at 24 and 48 hours. Preliminary assays mapped basic compound groups, while gas chromatography-mass spectrometry (GC-MS) isolated individual volatile fractions within TLEE. Every prepared treatment produced distinct, concentration-dependent larval fatalities. For Ae. aegypti , LSEE demonstrated superior lethal efficiency, establishing an LC 50 threshold of 172.851 ppm at 24 hours. In 48-hour evaluations targeting An. gambiae , TLEE LC 50 is 13.271 ppm and LSEE LC 50 is 20.370 ppm induced a complete 100% elimination rate at a mere 250 ppm. C. quinquefasciatus exhibited marked vulnerability toward LEEE at 48 hours, registering an LC 50 value of 49.090 ppm. Tannic substances appeared across all specimens, whereas LSEE and LEEE exclusively concentrated alkaloids, flavonoids, resins, and steroids. Analytical profiling of TLEE resolved 16 discrete compounds. These metrics validate that TLEE, LSEE, and LEEE possess powerful bio-insecticidal attributes, offering sustainable, eco-safe options for suppressing target mosquito populations.

Citer ce document

Accès au document

Texte intégral en lecture en ligne, réservé aux abonnés SPHAERO et aux membres de l'institution. Se connecter

Auteur(s)

Statistiques

Consultations : 1

Téléchargements : 0