Insecticidal activity of extracts derived from different parts of the mangrove tree rhizophora mucronata (rhizophoraceae) lam. Against three arthropods

Abstract

The insecticidal and antifeedant activity of extracts derived from different parts of the mangrove tree Rhizophora mucronata (Rhizophoraceae) Lam. is reported. The 70% ethanol extracts of leaves, bark, stem wood and pith were tested for toxicity against adults of the desert locust Schistocerca gregaria (Forskal), the 2 nd instar larvae of Aedes aegypti (L.) and the 1 st instar larvae of the brine shrimp Artemia salina (Leach). Antifeedant activity of the extracts was assessed through tests conducted on S. gregaria adults by the paper feeding protection bioassay. In tests carried out on A. aegypti mosquito larvae, bark and pith extracts showed high toxicity with 48 hour LC 50 's of 157.4 ppm and 168.3 ppm respectively. Stem wood extracts had low activity with an LC 50 of 1003.4 ppm while leaf extracts did not exhibit toxic effects at a concentration of 1000 ppm. A similar trend in activity was observed with antifeedant tests conducted on the desert locust S. gregaria and on toxicity tests carried out on A. salina larvae. The bulk of the active compounds are sequestered in the bark, pith and stem wood with the least being found in the leaves. The results indicate that R. mucronata is a potential source of botanical insecticides(s).

Dose-mortality, Cytotoxicity and Repellent Activity of <i>Abutilon hirtum</i> (Lam.) Sweet against <i>Callosobruchus chinensis</i> (L.), <i>Artemia salina</i> L. and <i>Tribolium castaneum</i> (Hbst.)

“…An insecticide does not have to cause high mortality on target organisms in order to be acceptable [23]. The findings of the present investigation receive supports from the experiment done on A. hirtum and its related species by previous researchers.…”

Larvicidal and pupicidal activity of synthesized silver nanoparticles using Leucas aspera leaf extract against mosquito vectors, Aedes aegypti and Anopheles stephensi

“…Today, the environmental safety of an insecticide is considered to be of paramount importance. An insecticide does not have to cause high mortality to target organisms to be effective (Kabaru & Gichia, 2001).…”

Toxicity effect of Delonix elata (Yellow Gulmohr) and predatory efficiency of Copepod, Mesocyclops aspericornis for the control of dengue vector, Aedes aegypti

“…Phytochemicals may serve as suitable alternatives to synthetic insecticides in future as they are relatively safe [4] , in expensive and are readily available medicinal plants for mosquitoes control would generate local employment, reduce dependence on expensive imported products and stimulate local efforts to enhance public health. Larvicidal activities of the plant extracts varied based on the plant species, the plant parts, the geographical location where the plants grown and its application method.…”

“…The percentage of mortality was 100% in first and second instars whereas 96%, 92% in third and fourth instars. Fitted probit-mortality curves for larvae indicated the median and 90% lethal concentrations of D. elata for instars [1][2][3][4] to be 4.91 (8.13), 5.16 (8.44), 5.95 (7.76) and 6.87 (11.23), respectively. The results indicate that leaf extract exhibits significant biological activity against life stages.…”