263 research outputs found
Estimation of Local Mean Population Densities of Japanese Beetle Grubs (Scarabaeidae: Coleoptera)
Insect populations tend to be patchy in distribution. Even when the mean population density is low, there may be local patches with high densities. As a result, estimates of mean populations may provide little information about the size or intensity of local patches within the sampled area. We compared the following 3 methods of estimating local population densities of insects: (1) with moving averages, a local mean population density is estimated as the mean of samples taken within a given radius of a central point, (2) with inverse distances, local means are estimated as weighted averages of samples; each sample is given a weight proportional to a power of the reciprocal of its distance from the center of the region for which the mean is to be estimated, (3) kriging is a geostatistical algorithm for estimating local means as weighted averages of samples. Weighting is based on the spatial covariance of the samples, or the degree to which samples that are near to each other are related. The first 2 methods are relatively easy to calculate but were unreliable when used with standard parameters to estimate local Japanese beetle grub densities. When an optimum radius was used with moving averages and an optimum exponent was used with inverse distances, the advantage of ease of calculation was lost, yet both methods were still inferior to kriging in providing accurate estimates of local mean
Age-Dependent Movement Patterns of Japanese Beetle and European Chafer (Coleoptera: Scarabeidae) Grubs in Soil-Turfgrass Microcosms
Movement patterns of japanese beetle, Popillia japonica Newman, and European chafer, Rhizotrogus (Amphimallon) majalis (Razoumowsky), grubs as influenced by gravity, host plant position, and external disturbances were studied in laboratory soil-turfgrass microcosms. Second through third instars just before pupation were monitored using radiographic techniques. Neonates were monitored using destructive sampling. Results demonstrate significantly different movement patterns between species and among age groups. The development stage of the grub had a large effect on Japanese beetle grub behavior and a measurable, but lesser effect, on European chafers. All larval stages of European chafers and all larval stages of Japanese beetle, except neonates and postoverwintering third instars, displayed a downward movement in response to disturbance. Neonate Japanese beetles showed little movement while postoverwintering. Japanese beetles moved upward when disturbed. European chafer grubs of all age classes displayed random vertical movement with some arrestment in or near sod. Preoverwintering and postoverwintering third-instar chafers showed less dramatic arrestment behavior than other instars tested. Second-instar Japanese beetles behaved similarly to European chafers; however, third instars behaved very differently. All third instars except those tested in late winter and early spring showed some innate downward movement in the soil microcosms. Japanese beetles tested in late winter displayed random movement with some arrestment in sod, whereas those tested in early spring exhibited upward movement and arrestment in so
Control Decision Rule for European Chafer (Coleoptera: Scarabaeidae) Larvae Infesting Turfgrass
A control decision rule for European chafer, Rhizotrogus (Amphimallon) majalis (Razoumowsky), larvae infesting turfgrass was developed using data from 317 residential sites. Larvae were often abundant enough to cause damage to turf in portions (patches) of properties when average density over an entire site was much less than a damage threshold of 5-10 grubs per 950 cm2. To account for this, an empirical relationship between the size of the largest patch of European chafer larvae at a site and site-wide density was used in the development of the decision rule. Properties with a patch of grubs in excess of ≍30 m2 were deemed to require insecticide treatment. Site characteristics (lawn age, shade, and percentage of Kentucky bluegrass) were related to site-wide density and this relationship was used to formulate a risk assessment system. This system is used to determine whether a site should be sampled or not. Properties that are not sampled are not to be treated. Other treatment decisions are based on the outcome of sampling. The relationship between site-wide density and patch size did not allow clear identification of a density that could be used as a threshold in a sampling program. Therefore, several sampling plans were constructed that classified density according to different threshold values. Operating characteristic functions were used in combination with the aforementioned relationship between density and patch size to calculate two types of errors for each sampling plan: the probability of not treating when treatment was necessary and the probability of treating when treatment was not required. Based on these error functions, a threshold of 0.25 grubs per ll-cm diameter turf plug was advocated. Use of the proposed control decision rule should result in few treatment errors but could lead to considerable reductions in pesticide us
Development and Evaluation of a Control Decision Rule for First-Generation Spotted Tentiform Leafminer (Lepidoptera: Gracillariidae) in New York Apple Orchards
A pest control decision rule consisting of an action threshold and a sampling protocol was developed and evaluated for first-generation spotted tentiform leafminer, Phyllonorycter blancardella (F.). An action threshold of two eggs per leaf was chosen based on the criterion of preventing more than one first-generation mine per leaf. Two sequential classification sampling plans for first-generation eggs were developed, one based on variable intensity sampling and the other on the use of confidence intervals for stop limits. Both plans made use of the nested variance structure of leafminer egg counts and variance-mean models fit to estimated variance components. Performance of the two sequential procedures was studied using simulation and judged to be very similar. Use of either sampling plan required approximately 10-20 min. Over a 4-yr period, 87% of sampled orchards in western New York had leafminer populations that were below the threshold of two eggs per leaf. During this period, use of sample information to schedule insecticide treatments resulted in only one instance when a treatment may have been required and was not called for (n = 79). Widespread use of the decision rule would result in significant reductions in pesticide use with no attendant increase in risk to grower
Behavioral Interactions Between Japanese Beetle (Coleoptera: Scarabaeidae) Grubs and an Entomopathogenic Nematode (Nematoda: Heterorhabditidae) within Turf Microcosms
Distribution of Japanese beetle, Popillia japonica Newman, grubs and dispersal of an entomopathogenic nematode, Heterorhabditis bacteriophora Poinar ‘Oswego' strain (an isolate from New York state), were examined for 5 wk within soil-filled flats containing grass. Japanese beetle grubs uniformly dispersed to all sections of the flats not infested with H. bacteriophora ‘Oswego' strain. In flats infested with H. bacteriophora ‘Oswego' strain, however, greater proportions of Japanese beetle grubs were recovered in sections near the nematode release site or center sections of the flats. H. bacteriophora ‘Oswego' strain dispersed to all sections of the flats but dispersed more rapidly within the flats infested with Japanese beetle grubs than in flats not infested with Japanese beetle grub
Interference with the Mate-Finding Communication System of the Obliquebanded Leafroller (Lepidoptera: Tortricidae) Using Synthetic Sex Pheromones
Effect of atmospheric permeation with synthetic sex pheromone on the behavior and control of obliquebanded leafroller, Choristoneura rosaceana (Harris), was studied in small and large plots in commercial apple orchards. Synthetic sex pheromone significantly reduced the ability of male moths to locate pheromone-baited traps and tethered females; however, no differences were found among 3 pheromone rates. Location of pheromone dispensers within the tree canopy did not alter the number of males locating pheromone-baited traps and mating tethered females. Obliquebanded leafroller activity was greatest in the upper positions of the tree canopy and no edge effect was observed around perimeters of large disrupted blocks. The presence of gravid feral females, mated tethered females, high larval densities, and fruit damage within large pheromone disrupted blocks indicate obliqubanded leafrollers mate in orchards treated with synthetic sex pheromone. However, fruit damage caused by obliquebanded leafroller larvae was similar in pheromone, pheromone plus insecticide, and insecticide treatment
Cascading tripartite binomial classification plans to monitor European red mite (Acari,Tetranychidae) through a season; development and evaluation of a new methodology for pest monitoring
Skeletal Muscle Measures as Predictors of Toxicity, Hospitalization, and Survival in Patients with Metastatic Breast Cancer Receiving Taxane-Based Chemotherapy
Severe skeletal muscle (SM) loss (sarcopenia), is associated with poor cancer outcomes including reduced survival and increased toxicity. This study investigates SM measures in metastatic breast cancer (MBC) patients receiving first line taxane-based chemotherapy and evaluates associations with treatment toxicity and other outcomes
Body Composition as a Predictor of Toxicity in Patients Receiving Anthracycline and Taxane–Based Chemotherapy for Early-Stage Breast Cancer
Poor body composition metrics (BCM) are associated with inferior cancer outcomes; however, in early breast cancer (EBC) there is a paucity of evidence regarding BCM’s impact on toxicities. This study investigates associations between BCM and treatment-related toxicity in EBC patients receiving anthracyclines-taxane based chemotherapy
Skeletal muscle measures and physical function in older adults with cancer: sarcopenia or myopenia?
BACKGROUND: Skeletal muscle loss, commonly known as sarcopenia, is highly prevalent in older adults and linked with adverse outcomes in cancer, yet the definition and role of sarcopenia remains uncertain. The aim of this study was to examine the association of Computerized Tomography (CT) assessed skeletal muscle measures with physical function in older adults with cancer.
RESULTS: CTs for 185 patients were available. Median age 73 (IQR 68-76) and 56.5% female. After controlling for sex and BMI, we found no evidence that SMI was associated with physical function impairments. Both SMD and SMG were associated physical function impairments and higher values were associated with decreased limitations in instrumental activities of daily living (RR 0.84 [CI 0.73-0.96] and 0.94 [CI 0.89-0.99], respectively), climbing stairs (RR 0.84 [CI 0.76-0.94] and 0.91 [CI 0.87-0.96]), walking 1 block (RR 0.77 [CI 0.67-0.90] and 0.91 [CI 0.85-0.97]), and prolonged Timed Up and Go (RR 0.83 [CI 0.75-0.92] and 0.92 [CI 0.88-0.96]).
MATERIALS AND METHODS: Using the Carolina Senior Registry, we identified patients with CT imaging performed within 60 days +/- of baseline geriatric assessment (GA). Skeletal muscle area and density (SMD) were analyzed from L3 lumbar segments. Muscle area and height (m2) were used to calculate skeletal muscle index (SMI). Skeletal Muscle Gauge (SMG) was created by multiplying SMI x SMD.
CONCLUSIONS: Skeletal muscle mass as assessed from CT imaging was not associated with physical function impairments. Skeletal muscle radiodensity was more associated with physical function and may aid in identifying older adults at risk for functional impairments
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