Resistance to the microbial insecticide Bacillus thuringiensis Berliner has evolved in field populations of diamondback moth, Plutella xylostella (L.), in Hawaii. Three field populations that had been treated repeatedly with commercial formulations of the sporecrystal protein complex of B. thuringiensis subsp. kurstaki developed significant resistance to it. The LC50 of the most resistant popul...

The toxicity of Cu, Mn, Mo, Ni, V, As, Pb, Cr, Hg and Sn on the behaviour and survival of benthic worms Tubifex tubifex was studied. All tested metals were dissolved and determined in tap water under standardized conditions. The adverse effects of the metals were evaluated as acute toxicological effects upon exposure expressed as LC50 value with 95% confidence interval. On the basis of the LC50...

In this study, five compounds, lupeol (1), epilupeol (2), β-sitosterol (3), stigmasterol (4) and p-methoxybenzaldehyde (5) were isolated from the petroleum ether and dichloromethane fractions of a methanolic extract of the stem bark of Delonix regia. Antimicrobial screening of the different extracts (15 μg mm-2) was conducted by the disc diffusion method. The zones of inhibition demonstrated by...

The effect of methanolic plant extracts from Solanum nigrum, Acokanthera spectabilis and Heliotropium aegyptiacum were investigated on the larval mortality and development of Culex pipiens L. Also, the effects of the LC50 of the three plant extracts on the larval haemogram were studied. Plant extracts exhibited variable bioactivities. The greatest activity was observed for S. nigrum which showe...

It is still not very clear what roles the various Ag species play in the toxicity of silver nanoparticles (AgNPs). In this study, we found that traditional exposure media result in uncontrollable but consistent physicochemical transformation of AgNPs, causing artifacts in determination of median lethal concentration (LC50) and hindering the identification of Ag species responsible for the acute...

Sublethal adverse effects may result from exposure of aquatic organisms to insecticides at environmentally relevant concentrations. Fingerlings of the common carp (Cyprinus carpio, Linnaeus, 1758), grass carp (Ctenopharyngodon idella, Valenciennes, 1844), and bighead carp (Aristichthys nobilis, Richardson, 1845) were exposed to diafuran, an insecticide widely used during rice cultivation in Sou...

Toxicity testing in AS52 cells (24-hr exposures) gave LC50 values of 2 to 130 micrograms Ni/ml for particulate nickel compounds and 45 to 60 micrograms Ni/ml for water-soluble salts (NiCl2, NiSO4, Ni(CH3COO)2). The Ni(OH)2, NiCO3, and sulfides (Ni3S2, Ni7S6, "amorphous NiS") exhibited similar toxicities (LC50's of 2 to 8 micrograms Ni/ml), while three nickel oxides were more variable and less t...

Over the past two decades, there has been an increased recognition of the importance of wild or locally cultivated food plants as sources of micronutrients and plant secondary metabolites. Green leafy vegetables (GLVS) have proved over time that they provide more protective energy to human body than any other vegetable.The present study concern about Anti-Oxidant, Anti-Amylase, Anti-Arthritic a...

Relatively little is known about the behavior and toxicity of nanoparticles in the environment. Objectives of work presented here include establishing the toxicity of a variety of silver nanoparticles (AgNPs) to Daphnia magna neonates, assessing the applicability of a commonly used bioassay for testing AgNPs, and determining the advantages and disadvantages of multiple characterization techniqu...

Acute and chronic toxicity of eight agricultural adjuvants (Bond, Kinetic, Plyac, R-11, Silwet L-77, Sylgard 309, X-77, and WaterMaxx) to Daphnia pulex were evaluated with 48-h acute lethal concentration estimates (LC50) and a 10-d population growth-rate measurement, the instantaneous rate of increase (r1). Based on LC50, the order of toxicity was R-11 > X-77 = Sylgard 309 = Silwet L-77 > Kinet...