Boric acid toxicity to the German cockroach, Blattella germanica: Alterations in midgut structure, and acetylcholinesterase and glutathione S-transferase activity

• Published in: Pesticide biochemistry and physiology Vol. 84; no. 1; pp. 17 - 24
• Main Authors: Habes, D., Morakchi, S., Aribi, N., Farine, J.-P., Soltani, N.
• Format: Journal Article
• Language: English
• Published: San Diego, CA Elsevier Inc 2006; Elsevier
• Subjects: Acetylcholinesterase; Biological and medical sciences; Blattella germanica; Blattellidae; Boric acid; Fundamental and applied biological sciences. Psychology; Glutathione S-transferase; glutathione transferase; insect control; insect physiology; intestinal mucosa; mechanism of action; Medically important nuisances and vectors, pests of stored products and materials: population survey and control; Midgut; Nuisances; Pesticides; Phytopathology. Animal pests. Plant and forest protection; Protozoa. Invertebrates; toxicity; Boric acid; Acetylcholinesterase; Glutathione S-transferase; Midgut; Blattella germanica; Pesticides; Enzyme; Toxicity; Insecta; Transferases; Blattellidae; Alteration; Esterases; Carboxylic ester hydrolases; Glutathione transferase; Arthropoda; Hydrolases; Invertebrata; Dictyoptera
• ISSN: 0048-3575; 1095-9939
• DOI: 10.1016/j.pestbp.2005.05.002

Oral toxicity of boric acid, an inorganic insecticide, was evaluated on German cockroach, Blattella germanica L. (Dictyoptera, Blattellidae). Newly emerged adults were exposed to various concentrations of boric acid incorporated into the diet. Results showed that treated insects exhibited toxic symptoms with a dose-dependent mortality. Histological study of midgut revealed alterations in the epithelial cells and a significant increase in the epithelium thickness. In a second series of experiments, the compound was investigated on the activities of acetylcholinesterase (AChE) and glutathione S-transferases (GSTs). Data showed that the compound induced GSTs and reduced the activity of AChE. From this experiment, it may be concluded that ingested boric acid caused death of insects perhaps ultimately by starvation via alterations of the midgut. Additionally, the compound seemed to present a neurotoxic action as evidenced by the symptoms of poisoning and the reduction in AchE activity.