Insecticidal and repellent activities of methanolic extract of Tribulus terrestris L. (Zygophyllaceae) against the malarial vector Anopheles arabiensis (Diptera: Culicidae).

Abstract

Methanolic extracts of leaves and seeds from, Tribulus terrestris(Zygophyllaceae) was tested against 3rd instar larvae and adults of mosquito, Anopheles arabiensisunder laboratory condition. The seeds extract showed high insecticidal activity at all concentrations compared to the leaves extract and the Lc50 was 36.5 and 123.1ppm for seeds and leaves extract, respectively. All extracts exhibited remarkable effects on the fecundity, fertility and sterility index of adult females resulted from treated larvae, but the seeds extract was more effective than leaves extract. The repellent action of the present plant extracts varied depending on the plant parts and the dose of extract. The seeds extract was more effective in exhibiting the repellent action (100%) against the mosquito tested as compared with the leaves extract (79.5%) at the dose 1.0 and 2.0mg/cm2, respectively. The seeds extract showed the same repellency percent (100%) of commercial formulation, N. N. diethyl toulamide (DEET) but at the lower dose (1.0mg/cm2).The extracts in this study showed strong larvicidal, pupicidal, adulticidal, ovicidal, repellency and biting deterrence and these extracts may be used for further integrated mosquito management programs.