34 research outputs found

    Sticky traps saturate with navel orangeworm in a nonlinear fashion

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    Trapping is an essential tool used to decide the need for and/or timing of an insecticide application. The assumption is that the information is accurate, but accuracy is dependent on trap reliability and efficacy. One factor that affects reliability is trap saturation, defined as the measurable decrease in trap capture due to reduced trapping effectiveness caused by the accumulation of insects already in a trap. In this study, we used unmated female navel orangeworm (NOW, Amyelois transitella (Walker)) as sex pheromone baits in wing traps that varied by color and glue/trapping surface in order to evaluate saturation thresholds and quantify trap effectiveness. Effectiveness decreased in each type of sticky trap as the number of insects caught increased, because of the accumulation of scales and insect bodies on the glue surface. The continued accumulation of insects further reduced trap capture, and this decrease in capture could be described by a regression using a power transformation. The resulting saturation equations that we calculated will help pest control advisers and growers interpret their trap data by better estimating the relationship between the number of males trapped versus those that visited the trap

    Bait formulations and longevity of navel orangeworm egg traps tested

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    Understanding the Potential Impact of Multiple Robots in Odor Source Localization

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    We investigate the performance of three bio-inspired odor source localization algorithms used in non-cooperating multi-robot systems. Our performance metric is the distance overhead of the first robot to reach the source, which is a good measure for the speed of an odor source localization algorithm. Using the performance distribution of single-robot experiments, we calculate an ideal performance for multi-robot teams. We carry out simulations in a realistic robotic simulator and provide quantitative evidence of the differences between ideal and realistic performances of a given algorithm. A closer analysis of the results show that these differences are mainly due to physical interference among robots

    Tracking Odor Plumes in a Laminar Wind Field with Bio-Inspired Algorithms

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    We introduce a novel bio-inspired odor source localization algorithm (surge- cast) for environments with a main wind ïŹ‚ow and compare it to two well-known algorithms. With all three algorithms, systematic experiments with real robots are carried out in a wind tunnel under laminar ïŹ‚ow conditions. The algorithms are compared in terms of distance overhead when tracking the plume up to the source, but a variety of other experimental results and some theoretical considerations are provided as well. We conclude that the surge-cast algorithm yields signiïŹcantly better performance than the casting algorithm, and slightly better performance than the surge-spiral algorithm

    Sticky traps saturate with navel orangeworm in a nonlinear fashion

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    Trapping is an essential tool used to decide the need for and/or timing of an insecticide application. The assumption is that the information is accurate, but accuracy is dependent on trap reliability and efficacy. One factor that affects reliability is trap saturation, defined as the measurable decrease in trap capture due to reduced trapping effectiveness caused by the accumulation of insects already in a trap. In this study, we used unmated female navel orangeworm (NOW, Amyelois transitella (Walker)) as sex pheromone baits in wing traps that varied by color and glue/trapping surface in order to evaluate saturation thresholds and quantify trap effectiveness. Effectiveness decreased in each type of sticky trap as the number of insects caught increased, because of the accumulation of scales and insect bodies on the glue surface. The continued accumulation of insects further reduced trap capture, and this decrease in capture could be described by a regression using a power transformation. The resulting saturation equations that we calculated will help pest control advisers and growers interpret their trap data by better estimating the relationship between the number of males trapped versus those that visited the trap

    Differential tending of worker and drone larvae of the honey bee, Apis mellifera, during the 60 hours prior to cell capping

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    Varroa destructor is a parasitic mite of A. mellifera. Female mites reproduce on both drone and worker brood; but they are found 5–9 times more often on drone brood. We examined larval tending by brood nest bees to determine if this behavior could provide an explanation for these differences. We observed workers tending worker and drone larvae in three observation colonies commencing 60 h prior to the completion of cell capping, an interval that includes the susceptible periods of both types of brood. Workers invested 2.78 times more time tending drone larvae than worker larvae, a difference due primarily to a greater number of tending acts directed towards drone brood. This finding demonstrates that phoretic mites may have more opportunity to enter drone brood. The 2.78 fold difference in time tending larvae combined with the previously reported 2–4-fold differences in the lengths of the periods when cells are capped could explain a 5.56–11.12 fold difference in mite levels in worker and drone brood, similar to `previously' reported differences

    Cowpea weevil flights to a point source of female sex pheromone: analyses of flight tracks at three wind speeds

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    Two-day-old male cowpea weevils, Callosobruchus maculatus, fly upwind to a point source of female sex pheromone at three wind speeds. All beetles initiating flight along the pheromone plume make contact with the pheromone source. Analysis of digitized flight tracks indicates that C. maculatus males respond similarly to moths tested at several wind speeds. Beetles’ mean net upwind speeds and speeds along their track are similar (P \u3e 0.05) across wind speeds, whereas airspeeds increase (P \u3c 0.01) with increasing wind speed. Beetles adjust their course angles to fly more directly upwind in higher wind speeds, whereas track angles are almost identical at each wind speed. The zigzag flight paths are generally narrow compared with most moth flight tracks and interturn distances are similar (P \u3e 0.05) at the wind speeds employed. The frequency of these counterturns across the wind line is almost constant regardless of wind speed, and there is little variation between individuals. The upwind flight tracks are more directly upwind than those typically seen for male moths flying upwind toward sex pheromone sources. Male moths typically produce a bimodal distribution of track angles to the left and right of the windline, whereas C. maculatus males’ track angles are centred about 0°. Preliminary examination of two other beetle species indicates that they fly upwind in a similar fashion
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