Screen Barriers for Reducing Interplot Movement of Three Adult Plant Bug (Hemiptera: Miridae) Species in Small Plot Experiments

Fiberglass screen barriers 1.2 m high were erected around small (7.3 x 3.7 m) plots of birdsfoot trefoil, Lotus corniculatus, to study the effectiveness of screen barriers in reducing adult plant bug migration into small field plots. Screened and unscreened (control) plots were sprayed with an insecticide at the onset of the experiment, and subsequent adult mirid migration into these trefoil plots was measured by sweep net samples during the following 24 day period. Combined adult Adelphocoris lineolatus, Lygus lineolaris, and Plagiognathus chrysanthemi densities were significantly lower in screened versus unscreened plots with 37070, 28010, and 23070 fewer adults at 7, 17, and 24 days, respectively, following insecticide application. Although these barriers were inexpensive and simple to construct, we conclude that they were not practical and effective enough for reducing adult mirid migration in small plot experiments of this type

Insect Pests Associated With Birdsfoot Trefoil, \u3ci\u3eLotus Corniculatus\u3c/i\u3e, in Wisconsin

Insect surveys taken during 1984-1986 in Ashland and Bayfield Counties of northern Wisconsin revealed that several potential insect pest species were common in birdsfoot trefoil, Lotus corniculatus. Three plant bug species, including: the tarnished plant bug, Lygus lineolaris: alfalfa plant bug, Adelphocoris lineolatus; and Plagiognathus chrysanthemi were abundant in most sampled fields. P. chrysanthemi was the most abundant species, was only present in the northern locations, and completed one generation per year. A. lineolatus and L. lineolaris were second and third in abundance, respectively, and completed two generations per year. Population levels of the potato leafhopper, Empoasca fabae. exceeded a combined total of 45 nymphs and adults per sweep in a southern Wisconsin location but were uncommon in northern Wisconsin. Present, but less abundant, were the trefoil seed chalcid, Bruchophagus platypterus; meadow spittlebug, Philaenus spumarius; and pea aphid, Acyrthosiphon pisum, all occurring at densities of less than one insect per sweep

Nutrient additions to mitigate for loss of Pacific salmon: consequences for stream biofilm and nutrient dynamics

Mitigation activities designed to supplement nutrient and organic matter inputs to streams experiencing decline or loss of Pacific salmon typically presuppose that an important pathway by which salmon nutrients are moved to fish (anadromous and/or resident) is via nutrient incorporation by biofilms and subsequent bottom-up stimulation of biofilm production, which is nutrient-limited in many ecosystems where salmon returns have declined. Our objective was to quantify the magnitude of nutrient incorporation and biofilm dynamics that underpin this indirect pathway in response to experimental additions of salmon carcasses and pelletized fish meal (a.k.a., salmon carcass analogs) to 500-m reaches of central Idaho streams over three years. Biofilm standing crops increased 2–8-fold and incorporated marine-derived nutrients (measured using 15N and 13C) in the month following treatment, but these responses did not persist year-to-year. Biofilms were nitrogen (N) limited before treatments, and remained N limited in analog, but not carcass-treated reaches. Despite these biofilm responses, in the month following treatment total N load was equal to 33–47% of the N added to the treated reaches, and N spiraling measurements suggested that as much as 20%, but more likely 2–3% of added N was taken up by microbes. Design of biologically and cost-effective strategies for nutrient addition will require understanding the rates at which stream microbes take up nutrients and the downstream distance traveled by exported nutrients

Riparian defoliation by the invasive green alder sawfly influences terrestrial prey subsidies to salmon streams

Invasive species in riparian forests are unique as their effects can transcend ecosystem boundaries via stream-riparian linkages. The green alder sawfly (Monsoma pulveratum) is an invasive wasp whose larvae are defoliating riparian thin-leaf alder (Alnus tenuifolia) stands across southcentral Alaska. To test the hypothesis that riparian defoliation by this invasive sawfly negatively affects the flow of terrestrial prey resources to stream fishes, we sampled terrestrial invertebrates on riparian alder foliage, their subsidies to streams and their consumption by juvenile coho salmon (Oncorhynchus kisutch). Invasive sawflies altered the composition of terrestrial invertebrates on riparian alder foliage and as terrestrial prey subsidies to streams. Community analyses supported these findings revealing that invasive sawflies shifted the community structure of terrestrial invertebrates between seasons and levels of energy flow (riparian foliage, streams and fish). Invasive sawfly biomass peaked mid-summer, altering the timing and magnitude of terrestrial prey subsidies to streams. Contrary to our hypothesis, invasive sawflies had no effect on the biomass of native taxa on riparian alder foliage, as terrestrial prey subsidies, or in juvenile coho salmon diets. Juvenile coho salmon consumed invasive sawflies when most abundant, but relied more on other prey types selecting against sawflies relative to their availability. Although we did not find effects of invasive sawflies extending to juvenile coho salmon in this study, these results could change as the distribution of invasive sawflies expands or as defoliation intensifies. Nevertheless, riparian defoliation by these invasive sawflies is likely having other ecological effects that merits further investigation

Stimulant Reduction Intervention using Dosed Exercise (STRIDE) - CTN 0037: Study protocol for a randomized controlled trial

<p>Abstract</p> <p>Background</p> <p>There is a need for novel approaches to the treatment of stimulant abuse and dependence. Clinical data examining the use of exercise as a treatment for the abuse of nicotine, alcohol, and other substances suggest that exercise may be a beneficial treatment for stimulant abuse, with direct effects on decreased use and craving. In addition, exercise has the potential to improve other health domains that may be adversely affected by stimulant use or its treatment, such as sleep disturbance, cognitive function, mood, weight gain, quality of life, and anhedonia, since it has been shown to improve many of these domains in a number of other clinical disorders. Furthermore, neurobiological evidence provides plausible mechanisms by which exercise could positively affect treatment outcomes. The current manuscript presents the rationale, design considerations, and study design of the National Institute on Drug Abuse (NIDA) Clinical Trials Network (CTN) CTN-0037 Stimulant Reduction Intervention using Dosed Exercise (STRIDE) study.</p> <p>Methods/Design</p> <p>STRIDE is a multisite randomized clinical trial that compares exercise to health education as potential treatments for stimulant abuse or dependence. This study will evaluate individuals diagnosed with stimulant abuse or dependence who are receiving treatment in a residential setting. Three hundred and thirty eligible and interested participants who provide informed consent will be randomized to one of two treatment arms: Vigorous Intensity High Dose Exercise Augmentation (DEI) or Health Education Intervention Augmentation (HEI). Both groups will receive TAU (i.e., usual care). The treatment arms are structured such that the quantity of visits is similar to allow for equivalent contact between groups. In both arms, participants will begin with supervised sessions 3 times per week during the 12-week acute phase of the study. Supervised sessions will be conducted as one-on-one (i.e., individual) sessions, although other participants may be exercising at the same time. Following the 12-week acute phase, participants will begin a 6-month continuation phase during which time they will attend one weekly supervised DEI or HEI session.</p> <p>Clinical Trials Registry</p> <p>ClinicalTrials.gov, <a href="http://www.clinicaltrials.gov/ct2/show/NCT01141608">NCT01141608</a></p> <p><url>http://clinicaltrials.gov/ct2/show/NCT01141608?term=Stimulant+Reduction+Intervention+using+Dosed+Exercise&rank=1</url></p

Getting Quantitative about Consequences of Cross-Ecosystem Resource Subsidies on Recipient Consumers

Most studies of cross-ecosystem resource subsidies have demonstrated positive effects on recipient consumer populations, often with very large effect sizes. However, it is important to move beyond these initial addition-exclusion experiments to consider the quantitative consequences for populations across gradients in the rates and quality of resource inputs. In our Introduction paper to this special issue, we describe at least four potential models that describe functional relationships between subsidy input rates and consumer responses, most of them asymptotic. Here we aim to advance our quantitative understanding of how subsidy inputs influence recipient consumers, and the communities they are part of. In the papers following, fish were either the recipient consumers or the subsidy as carcasses of anadromous species. Advancing general, predictive models will enable us to further consider what other factors are potentially co-limiting (e.g. nutrients, other population interactions, physical habitat, etc.) and better integrate resource subsidies into consumer-resource, bio-physical dynamics models.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Influence of salmon carcasses on stream productivity: response of biofilm and benthic macroinvertebrates in southeastern

Abstract: This study was conducted to determine if salmon carcasses (from spawning adults) increased stream biofilm ash-free dry mass (AFDM) and benthic macroinvertebrate abundance in southeastern Alaska, U.S.A. Thirty-six once-through artificial streams were situated along, and received water and drifting invertebrates from, a natural stream. Two treatments (salmon carcass, control) were sampled six times during a 3-month period in a randomized incomplete block design with a 2 × 6 factorial treatment structure. Additionally, two natural stream sites were sampled once for biofilm and macroinvertebrates, one site receiving 75 000 adult salmon migrants during 1996 and the other upstream of spawning salmon. While biofilm AFDM was 15 times higher in carcass-enriched reaches of Margaret Creek, there were no detectable treatment differences in the artificial streams. Total macroinvertebrate densities were up to eight and 25 times higher in carcass-enriched areas of artificial and natural streams, respectively; Chironomidae midges, Baetis and Cinygmula mayflies, and Zapada stoneflies were the most abundant taxa. The increased biofilm in Margaret Creek and macroinvertebrate abundance in both systems suggest that salmon carcasses elevated freshwater productivity. This marine-based positive feedback mechanism may be crucial for sustaining aquatic-riparian ecosystem productivity and long-term salmonid population levels. Résumé : La présente étude visait à déterminer si les carcasses de saumon (géniteurs adultes) augmentaient la masse sèche exempte de cendres du film biologique d&apos;un cours d&apos;eau et l&apos;abondance des macroinvertébrés benthiques dans le sud-est de l&apos;Alaska (É.-U.). Trente-six cours d&apos;eau artificiels à circulation ouverte ont été créés le long d&apos;un cours d&apos;eau naturel qui les alimentait en eau et en invertébrés à la dérive. Deux groupes de traitement (carcasse de saumon, témoin) ont été échantillonnés six fois pendant une période de trois mois dans le cadre d&apos;un plan expérimental en blocs aléatoires incomplets avec une structure de traitement factorielle de 2 × 6. En outre, on a prélevé des échantillons de film biologique et de macroinvertébrés dans deux sites de cours d&apos;eau naturels, un site recevant 75 000 saumons adultes migrants en 1996 et l&apos;autre situé en amont de la frayère. Alors que le film biologique de masse sèche exempte de cendres était 15 fois plus élevé dans les tronçons du ruisseau Margaret enrichis par les carcasses, il n&apos;y avait aucune différence de traitement décelable dans les cours d&apos;eau artificiels. La densité totale de macroinvertébrés était respectivement jusqu&apos;à huit et 25 fois supérieure dans les zones enrichies de carcasses des cours d&apos;eau artificiels et naturels; les moucherons chironomidés, les éphémères Baetis et Cinygmula et les perles Zapada étaient les groupes les plus abondants. L&apos;accroissement du film biologique dans le ruisseau Margaret et de l&apos;abondance des macroinvertébrés dans les deux systèmes semblent indiquer que les carcasses de saumon font augmenter la productivité des eaux douces. Ce mécanisme de rétroaction positive provenant du milieu marin peut être critique pour le maintien de la productivité de l&apos;écosystème aquatique et riverain et les niveaux de population de salmonidés à long terme. [Traduit par la Rédaction

Resident trout consumption of salmon carcass and analog added to tributaries of the N. Fork Boise River, Idaho

After completing spawning, Pacific salmon die and their carcasses provide an important marine-derived subsidy for freshwater and terrestrial ecosystems. Their reduction or absence from some ecosystems in the Pacific Northwest has prompted the use of nutrient mitigation techniques as a means of offsetting perceived lost productivity in these systems. We conducted an experiment using salmon carcass (n=3), analog pellets (n=3), and control (n=3) treatments in 500-m reaches of nine tributaries on the North Fork Boise River, Idaho. We hypothesized that salmon carcass and analog material would be directly consumed by resident fishes. Rainbow trout (Oncorhynchus mykiss) and brook trout (Salvelinus fontinalis) were collected by electro-fishing before, and 2, 4, and 6 weeks after treatment additions, and gut contents were obtained via non-lethal gastric-lavage. Diet items were separated into aquatic invertebrate, terrestrial invertebrate, and treatment (i.e., carcass, analog) categories. Both carcass and analog were present in the diets through time and gradually declined. Salmon carcass material comprised 50% of the diets at 2-weeks after treatment and decreased to 10% at 6 weeks. Analog material comprised 30% of the diet at 2 weeks, and decreased to 10% at 6 weeks. Based on this linear decline, we predicted that no treatment would persist in trout diets in carcass streams after 50 days and analog streams after 55 days. Conservative estimates of analog treatment consumption by trout populations ranged from 7 to 18 kg, which was 1.5 to 3.8% total treatment loading. Carcass consumption ranged from 17 to 35 kg, or 1.8 to 2.3% of total loading. Our study shows that salmon carcass and analog treatments provide a food source for resident trout. Further research is being conducted to determine how this alternative diet may affect growth rates and population dynamics

A critical assessment of the ecological assumptions underpinning compensatory mitigation of salmon-derived nutrients

We critically evaluate some of the key ecological assumptions underpinning the use of nutrient replacement as a means of recovering salmon populations and a range of other organisms thought to be linked to productive salmon runs. These assumptions include: (1) nutrient mitigation mimics the ecological roles of salmon, (2) mitigation is needed to replace salmon-derived nutrients and stimulate primary and invertebrate production in streams, and (3) food resources in rearing habitats limit populations of salmon and resident fishes. First, we call into question assumption one because an array of evidence points to the multi-faceted role played by spawning salmon, including disturbance via redd-building, nutrient recycling by live fish, and consumption by terrestrial consumers. Second, we show that assumption two may require qualification based upon a more complete understanding of nutrient cycling and productivity in streams. Third, we evaluate the empirical evidence supporting food limitation of fish populations and conclude it has been only weakly tested. On the basis of this assessment, we urge caution in the application of nutrient mitigation as a management tool. Although applications of nutrients and other materials intended to mitigate for lost or diminished runs of Pacific salmon may trigger ecological responses within treated ecosystems, contributions of these activities toward actual mitigation may be limited