Development of Fungal Applications on Netting Substrates for Malaria Vector Control

Mosquito resistance to chemical insecticides is considered a serious threat for the sustainable use of contemporary malaria vector control methods. Fungal entomopathogens show potential as alternative biological control agents against (insecticide-resistant) anophelines. This study was designed to test whether the fungus, Beauveria bassiana, could be delivered to mosquitoes on netting materials that might be used in house screens, such as eave curtains. Tests were conducted to determine effects of formulation, application method, netting material, and nature of mosquito contact. Beauveria had a twice as high impact on Anopheles gambiae s.s. longevity when suspended in Shellsol solvent compared with Ondina oil (HR = 2.12, 95% confidence interval = 1.83–2.60, P 90% of mosquitoes within 10 d. Results indicate that the use of fungal spores dissolved in Shellsol and sprayed on small-meshed cotton eave curtain nets would be the most promising option for field implementation. Biological control with fungus-impregnated eave curtains could provide a means to target host-seeking mosquitoes upon house entry, and has potential for use in integrated vector management strategies, in combination with chemical vector control measures, to supplement malaria control in areas with high levels of insecticide resistance

Field-aged phosphate impacts on glyphosate and phosphorus sorption patterns in two prairie soils

Non-Peer ReviewedThis research measured field-aged phosphate concentrations in sandy clay-loam, clay-loam soils and utilized samples in batch equilibrium studies to quantify adsorption maximum of phosphate and glyphosate retention. Soil samples were collected in 2013 from two research sites that had received annual applications of mono ammonium phosphate at different rates from 2002 to 2009. The effect of fresh phosphate addition on glyphosate sorption in soil was also determined. Measured parameters were the glyphosate sorption distribution constant, Kd, as well as the Langmuir adsorption constants, b (phosphorus adsorption maximum), and k (affinity constant). Glyphosate Kd values significantly decreased with increasing phosphate level in soils, regardless of the background liquid (CaCl2 and KCl) used in the batch equilibrium experiment. Applications of potassium dihydrogen phosphate in the laboratory with glyphosate reduced the available sorption sites to retain glyphosate in soil. Field-aged phosphate did not significantly influence the adsorption maximum (b), but b was significantly higher with CaCl2 than KCl as background liquid. The affinity constant was significantly greater in soils with lower field-aged phosphate concentrations, suggesting that these soils had more readily-available sorption sites for phosphate than soils with higher phosphate concentrations