Toxicity of Chenopodium Ambrosioides L. (Chenopodiaceae) Products From Nigeria Against Three Storage Insects

Abstract

Toxicity ofChenopodium AmbrosioidesL. (Chenopodiaceae) Products From Nigeria Against Three Storage InsectsTests were carried out to study the toxicity, oviposition suppression, ovicidal and larvicidal effects ofChenopodium ambrosioidesL. as powder, extracts and essential oil againstCallosobruchus maculatusF. (Coleoptera: Bruchidae),Sitophilus zeamaisMotschulsky (Coleoptera: Curculionidae) andTribolium castaneumJacqueline du Val. (Coleoptera: Tenebrionidae). The powder formulation was more toxic toS. zeamaisthan eitherC. maculatusorT. castaneumwith 48 h LC50values of 0.46 g/kg, 1.60 g/kg and 2.14 g/kg, respectively. Ethanol extract was more toxic toC. maculatuswith a 48 h LC50value of 0.023 g/l, than other test insect species. The essential oil treatment demonstrated higher fumigant toxicity againstC. maculatusthanS. zeamaiswith 24 h LC50values of 1.33 μl/l and 1.90 μl/l respectively. The oil vapour showed activity againstC. maculatusegg, but had no appreciable larval mortality. The weight loss of grains admixed withC. ambrosioidespowder was lower than the controls after 150 days of field storage.

Toxicity of Boldo Peumus boldus Molina for Sitophilus zeamais Motschulsky and Tribolium castaneum Herbst

“…However, this species is less affected than S. zeamais for which concentrations of 8.0 and 16.0% lead to 100% mortality at 14 DAI. The reduced sensibility of T. castaneum to vegetable powders agrees with data found by Denloye et al (2010), who obtained higher mortality with extracts (LC 50 = 0.04 g L -1…”

Efficacy of <i>Cymbopogon citratus</i> Stapf leaf extract as seed protectant against <i>Sitophilus zeamais</i> Motschulsky (Coleoptera: Curculionidae) on stored maize (<i>Zea mays</i> L.)

“…This is probably due to the possession of strong elytra that covers the entire abdomen of the insect. This confirmed earlier works by Inyang (2004), Akpabot et al(2010) and Edelduok et al (2012) who posited that coleopterans have exceptionally thick cuticles, epidermis and basement membrane as effective mechanisms of restricting toxicants absorption but disagreed with earlier work by Epidi et al (2009), Denloye et al (2010) and Udo et al(2011) who observed significant contact action on S. zeamais since they are known to be poor fliers and so were always in contact with the treated filter paper. Again, the body size of S. zeamais might enhance its efficiency in detoxifying any toxic materials in the plant product applied.…”

“…The powders were sieved using 0.5 mm size mesh. The powder was then stored in an airtight container to prevent active components from evaporating prior to used (Denloye et al, 2010).…”

Efficacy of two plant powders as cowpea grain protectants against <i>Callosobruchus maculatus</i> Fabricius (Coleoptera, Chrysomelideae: Bruchinae)

“…Some studies proved efficacy of C. ambrosioides for controlling C. maculatus including toxicity to adults, reduction of oviposition, ovicidal activity and toxicity to immature stages prior to or immediately following penetration of plant tissue (Tapondjou et al, 2002;Emeasor, 2005;Denloye et al, 2010). High mortality rates obtained in this study are in accordance with the results reported by Chougourou et al, 2015, which had 100% of mortality of C. maculatus with 1.5g of C. ambrosioides per 20g of Vigna subterranea, 120 hours after treatment.…”

“…There is now renewed interest in the use of pesticides of plant origin in order to obviate the problems of environmental pollution, killing of non-target species and humans as well as reducing cost of purchasing synthetic chemical pesticides. In this context, several plants and constituent bioactive substances, also called insecticides of plant origin or botanical insecticides, have been tested and considered promising in the control of cowpea beetle (Denloye et al, 2010, Kheradmand et al, 2010, Udo, 2011. Chenopodium ambrosioides Linn and Aframomum melegueta K. Schum were chosen because they have shown promise of medicinal and insecticidal activity in Malawi, Central Africa countries such as Cameroon and Gabon and Southern Africa (Gadano, 2002, Tapondjou et al, 2002, Konning et al, 2004Okwu, 2005, Odugbemi, 2006, Denloye et al, 2009.…”