Neonicotinoids are a popular and widely-used class of insecticides whose heavy usage rates and purported negative impacts on bees and other beneficial insects has led to questions about their mobility and accumulation in the environment. Neonicotinoid compounds are currently registered for over 140 different crop uses in the United States, with commercial growers continuing to rely heavily on neonicotinoid insecticides for the control of key insect pests through a combination of in-ground and foliar applications. In 2008, the Wisconsin Department of Agriculture, Trade and Consumer Protection (DATCP) began testing for neonicotinoids in groundwater test wells in the state, reporting detections of one or more neonicotinoids in dozens of shallow groundwater test wells. In 2011, similar detection levels were confirmed in several high-capacity overhead center-pivot irrigation systems in central Wisconsin. The current study was initiated to investigate the spatial extent and magnitude of neonicotinoid contamination in groundwater in and around areas of irrigated commercial agriculture in central Wisconsin. From 2013–2015 a total of 317 samples were collected from 91 unique high-capacity irrigation wells and tested for the presence of thiamethoxam (TMX), a neonicotinoid, using enzyme-linked immunosorbent assays. 67% of all samples were positive for TMX at a concentration above the analytical limit of quantification (0.05 μg/L) and 78% of all wells tested positive at least once. Mean detection was 0.28 μg/L, with a maximum detection of 1.67 μg/L. Five wells had at least one detection exceeding 1.00 μg/L. Furthermore, an analysis of the spatial structure of these well detects suggests that contamination profiles vary across the landscape, with differences in mean detection levels observed from landscape (25 km), to farm (5 km), to individual well (500 m) scales. We also provide an update of DATCP’s neonicotinoid monitoring in Wisconsin’s shallow groundwater test wells and private potable wells for the years 2011–2017.
The Colorado potato beetle (Leptinotarsa decemlineata) is a major agricultural pest of solanaceous crops. An effective management strategy employed by agricultural producers to control this pest species is the use of systemic insecticides. Recent emphasis has been placed on the use of neonicotinoid insecticides. Despite efforts to curb resistance development through integrated pest management approaches, resistance to neonicotinoids in L.decemlineata populations continues to increase. One contributing factor may be alterations in insect fatty acids, which have multiple metabolic functions and are associated with the synthesis of xenobiotic-metabolizing enzymes to mitigate the effects of insecticide exposure. In this study, we analyzed the fatty acid composition of L. decemlineata populations collected from an organic production field and from a commercially managed field to determine if fatty acid composition varied between the two populations. We demonstrate that a population of L. decemlineata that has a history of systemic neonicotinoid exposure (commercially managed) has a different lipid composition and differential expression of known --
BACKGROUND The purse-string suture (PSS) is a simple, reversible method for reconstructing skin cancer defects. Its utility may be underappreciated in head and neck reconstructive surgery. OBJECTIVE To evaluate the utility of the PSS as an adjunct to the reconstructive ladder when reconstructing head and neck skin cancer defects. MATERIALS AND METHODS This prospective nonrandomized cohort included 109 consecutive adult patients with head and neck defects resulting from skin cancer resection. The PSS was placed in every patient after resection. Patients were evaluated before and after suture placement, and final reconstructive methods were recorded. RESULTS The PSS resulted in a mean defect area reduction of 77.1% (p < .001) and was used in the final reconstruction in 79 (72.5%) patients. The PSS reduced the number of patients requiring adjacent tissue transfer (11), regional tissue transfer (3), and free tissue transfer (1) by 69.4%, 70%, and 80%, respectively. Fifty patients underwent reconstruction in the operating room. After intraoperative placement of the PSS, it was determined that 22 (44.0%) of these defects could have been reconstructed in the clinic (p = .003). CONCLUSION The PSS dramatically reduces defect size, simplifies reconstructive techniques, and often permits reconstruction to be performed in the clinic rather than the operating room.
Spotted-wing drosophila, Drosophila suzukii (Matsumura) (Diptera: Drosophilidae), is an invasive economic pest of soft-skinned and stone fruit across the globe. Our study establishes both a predictive generalized linear mixed model (GLMM), and a generalized additive mixed model (GAMM) of the dynamic seasonal phenology of D. suzukii based on four years of adult monitoring trap data in Wisconsin tart cherry orchards collected throughout the growing season. The models incorporate year, field site, relative humidity, and degree days (DD); and relate these factors to trap catch. The GLMM estimated a coefficient of 2.21 for DD/1000, meaning for every increment of 1000 DD, trap catch increases by roughly 9 flies. The GAMM generated a curve based on a cubic regression smoothing function of DD which approximates critical DD points of first adult D. suzukii detection at 1276 DD, above average field populations beginning at 2019 DD, and peak activity at 3180 DD. By incorporating four years of comprehensive seasonal phenology data from the same locations, we introduce robust models capable of using DD to forecast changing adult D. suzukii populations in the field leading to the application of more timely and effective management strategies.
Aster Yellows phytoplasma (AYp; Candidatus Phytoplasma asteris) is associated with diseases of herbaceous plants, including ornamentals and important commercial vegetable and grain crops. The aster leafhopper (ALH; Macrosteles quadrilineatus Forbes) is the predominant vector of these bacteria, though other leafhopper species can acquire and transmit AYp. Potentially inoculative leafhoppers are reported to overwinter in the southern United States and migrate to northern latitudes in the spring. Examining the genetic similarities and differences in AYp associated with southern and northern populations of ALH may provide insight into the role that migrating ALH play in AYp disease development. To investigate similarities among geographically distinct populations of ALH and characterize the variation in AYp associated within these populations, we identified genetic variations in subgroup designation and the relative proportions of secreted AY-WB proteins from field-collected populations of AYp isolated from ALH from select locations in the southern (Arkansas, Kansas, Oklahoma, and Texas) and the northern United States (Wisconsin) in 2016, 2017, and 2018. Isolated phytoplasma were tested for variation of AYp genotypes, numbers of potentially inoculative (AYp-positive) ALH, and presence of specific AYp virulence (effector) genes. Geographically distinct populations of ALH collected in northern and southern regions were similar in CO1 genotype but carried different proportions of AYp genotypes. While similar AYp strains were detected in geographically distinct locations, the proportion of each genotype varied over time.
During the past 30 years, at least seven species of injurious insects are known to have evolved strains that are more difficult to kill with recognised chemical insecticides than are the normal populations of these pests.In 1939 it was reported from the East London area that farmers were experiencing difficulty in controlling the one host blue tick, B. decoloratus, by regular dipping in the recognised 7-day strength arsenical wash. Field observations confirmed this.A technique for treating ticks in the laboratory is discussed in detail. This technique has been put to exhaustive test and some 15,000 adult female blue ticks have been subjected to in vitro treatments with remarkably consistent results.Experiments are discussed that suggest that arsenic kills ticks by contact. It is further claimed that by using the technique described it has been possible to furnish proof that an arsenic-resistant strain of B. decoloratus does exist in South Africa. It would seem that when once the arsenic-resistant tick has established itself on any farm, the continued dipping of cattle in arsenical washes results in an unintentional artificial selection of those varieties within the tick population that are resistant to arsenic. Continued dippings in arsenic thus aggravate the position and some insecticide other than arsenic should be used to combat this arsenic-resistant strain of B. decoloratus.Gammexane was experimented with and it is shown that 0·005 per cent. is sufficient to kill adult females of the arsenic-resistant tick and could be taken as a basis for further experiments. Oil base preparations and water suspensions of Gammexane are twenty times more toxic to the tick than are dust preparations.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.