Parasite movement within different substrates is an important factor for reaching a host and completing the parasitic life-cycle Entomopathogenic nematodes (EPNs) have a specialized infective juvenile stage (IJ), which is mobile and has the capability seek insect hosts to penetrate into their haemocoel. EPNs are primarily applied to soil as biological control agents; thus, the IJs must move through the soil environment to find and then infect a host. In prior research, ascaroside pheromones were shown to enhance EPN movement in soil. Additionally, soil type is known to be an important factor that can affect the efficiency of EPN movement behavior. However, prior to our research it was unknown whether soil type has a differential effect on pheromone enhanced EPN movement. In different soils, we studied vertical movement of Steinernema carpocapsae, Steinernema feltiae and Heterorhabditis bacteriophora with and without pheromone exposure. All nematodes were evaluated in separate columns filled with oven dried sand versus two soil types from pecan orchards. Approximately 3,500 IJs of each nematode species were added to the top of the each column and incubated at 25°C for 3 days. Soil movement was determined by baiting the bottom section of each column with larvae of the yellow mealworm, (Tenebrio molitor L.). Movement with and without pheromones and across soil types was compared by ANOVA.
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