Neonicotinoids are one of the world's most extensively used insecticides, but their sub-lethal influences on non-target and beneficial organisms are not well known. Here we exposed the orb web spider Parawixia audax, which is found on arable lands in Uruguay, to a sub-lethal concentration of the broad spectrum insecticide Geonex (thiamethoxam + lambda-cyhalothrin) and monitored their web building. We collected their major ampullate silk and subjected it to tensile tests, wide-angle X-ray diffraction (WAXS) analysis, and amino acid composition analysis. Around half of the exposed spiders failed to build webs. Those that built webs produced irregular webs lacking spiral threads. The mechanical properties, nanostructures, and amino acid compositions of the silk were all significantly affected when the spiders were exposed to insecticides. We found that silk proline, glutamine, alanine and glycine compositions differed between treatments, indicating that insecticide exposure induced downregulation of the silk protein MaSp2. The spiders in the control group had stronger, tougher and more extensible silks than those in the insecticide exposed group. Our WAXS analyses showed the amorphous region nanostructures became misaligned in insecticide exposed silks, explaining their greater stiffness. While the insecticide dose we subjected P. audax to was evidently sub-lethal, the changes in silk physicochemical properties and the impairment to web building will indelibly affect their ability to catch prey.
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http://dx.doi.org/10.1016/j.chemosphere.2017.04.079 | DOI Listing |
Ecotoxicol Environ Saf
January 2025
Hangzhou Xiaoshan Hospital of Traditional Chinese Medicine, Hangzhou, Zhejiang, China; Research Institute of Orthopedics, the Jiangnan Hospital affiliated to Zhejiang Chinese Medical University, Hangzhou, Zhejiang, China. Electronic address:
Chlorpyrifos (CPF) is a broad-spectrum organophosphate chloride (OP) insecticide widely used in domestic use and open field. However, there is currently no relevant research revealing the toxic effects of CPF exposure on the skin, then it is necessary to comprehensively understand the toxic effects and mechanisms. The results showed that the skin tissue structure and function of mice were significantly disrupted after CPF exposure.
View Article and Find Full Text PDFPLoS One
January 2025
Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, North Carolina, United States of America.
Vector control is essential for eliminating malaria, a vector-borne parasitic disease responsible for over half a million deaths annually. Success of vector control programs hinges on community acceptance of products like long-lasting insecticide-treated nets (LLINs). Communities in malaria-endemic regions often link LLIN efficacy to their ability to control indoor pests such as bed bugs (Cimex lectularius L.
View Article and Find Full Text PDFSci Rep
January 2025
Animal Toxicology and Physiology Speciality Research Unit, Zoology Department, Faculty of Science, Kasetsart University, Bangkok, 10900, Thailand.
The brown planthopper (BPH) Nilaparvata lugens (Stål) is a major insect pest of Oryza sativa that causes crop yield loss in tropical regions, including Thailand. In this study, the crude ethanolic extract of the leaves and branches of Combretum trifoliatum , its active isolated components, apigenin and camphor, and Finopril were tested for their ability to control the first to fifth instars of N. lugens.
View Article and Find Full Text PDFFront Physiol
December 2024
Institute of Disinfection and Pest Control, Beijing Center for Disease Prevention and Control, Beijing, China.
Background: (Skuse) is an invasive and widespread mosquito species that can transmit dengue, chikungunya, yellow fever, and Zika viruses. Its control heavily relies on the use of insecticides. However, the efficacy of the insecticide-based intervention is threatened by the increasing development of resistance to available insecticides.
View Article and Find Full Text PDFActa Trop
December 2024
Department of Entomology, Aggeu Magalhães Institute/Oswaldo Cruz Foundation (IAM/Fiocruz), Recife, Pernambuco, Brazil.
This study characterizes the Aedes aegypti population from Fernando de Noronha Island, Pernambuco, Brazil, prior to implementing the Sterile Insect Technique (SIT). The main objective was to assess changes in glutathione S-transferase (GST) enzyme activity, previously linked to cypermethrin resistance in this population, in 2010. GST activity was measured in both male and female mosquitoes, masse produced in lab, after exposure to ionizing radiation.
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