Biology subjects

Gubler, W. D.

Publications and source records attributed to Gubler, W. D..

2 recordsLinked to original sources

bioRxiv2020

Imidacloprid Movement into Fungal Conidia is Lethal to Mycophagous Beetles

O_LIApplications of systemic pesticides can have unexpected direct and indirect effects on nontarget organisms, producing ecosystem-level impacts. C_LIO_LIWe investigated whether a systemic insecticide (imidacloprid) could be absorbed by a plant pathogenic fungus infecting treated plants and whether the absorbed levels were high enough to have detrimental effects on the survival of a mycophagous beetle. Beetle larvae fed on these fungi were used to assess the survival effects of powdery mildew and imidacloprid in a factorial design. Fungal conidia were collected from treated and untreated plants and were tested for the presence and concentration of imidacloprid. C_LIO_LISurvival of beetles fed powdery mildew from imidacloprid-treated leaves was significantly lower than that of beetles from all other treatments. C_LIO_LIImidacloprid accumulated in fungal conidia and hyphae was detected at levels considered lethal to other insects, including coccinellid beetles. C_LIO_LIWater-soluble systemic insecticides may disrupt mycophagous insects as well as other nontarget organisms, with significant implications for biodiversity and ecosystem function. C_LI

ecology↗

bioRxiv2018

Modeling Uncertainty in Grapevine Powdery Mildew Epidemiology Using Fuzzy Logic

Powdery mildew is the most important disease of grapevines worldwide. Despite the potential for rapid spread by the causal pathogen, grape powdery mildew has been effectively managed using fungicide applications applied based on a calendar schedule or modeled disease risk index. Various epidemiological models for predicting disease development or risk have helped to improve disease management. The Gubler-Thomas (GT) risk index is a popular disease risk model used by many growers in the western U.S. We modified the GT risk index using fuzzy logic to address both biological and mechanical uncertainty in the pathosystem. The spraying schedule suggested by the fuzzy-modified GT risk index was tested in eight site-years. Overall, the fuzzy-modified risk index maintained comparable levels of disease control as both the original model and a calendar based treatment, and had significantly less disease than the untreated control. The fungicide use efficiency of the fuzzy-modified GT risk index suggests that the updated risk index was significantly more efficient with fungicide applications than both the calendar and original GT risk index.

epidemiology↗