Combined stress from parasites, pesticides and lack of flowers drives bee declines

Bees are subject to numerous pressures in the modern world. The abundance and diversity of flowers has declined, bees are chronically exposed to cocktails of agrochemicals, and they are simultaneously exposed to novel parasites accidentally spread by humans. Climate change is likely to exacerbate these problems in the future. Stressors do not act in isolation; for example pesticide exposure can impair both detoxification mechanisms and immune responses, rendering bees more susceptible to parasites. It seems certain that chronic exposure to multiple, interacting stressors is driving honey bee colony losses and declines of wild pollinators, but such interactions are not addressed by current regulatory procedures and studying these interactions experimentally poses a major challenge. In the meantime, taking steps to reduce stress on bees would seem prudent; incorporating flower-rich habitat into farmland, reducing pesticide use through adopting more sustainable farming methods, and enforcing effective quarantine measures on bee movements are all practical measures that should be adopted. Effective monitoring of wild pollinator populations is urgently needed to inform management strategies into the future

Grape Expectations: A Survey of British Vineyard Land Management Practices From an Environmental Perspective

Traditional vineyard landscapes are generally intensively managed with heavy reliance on synthetic pesticides. Viticulture is one of the fastest-growing sectors of English agriculture and information on land management is essential to secure a sustainable future. We surveyed viticulturists to ascertain vineyard pest presence, pest control, inter-row ground cover and wildflower use. The majority of viticulturists reported the presence of vineyard pests and relied heavily on pesticides, with 74% using synthetic pest control, 40% using herbicides, 40% using fungicides. Inter-row, 66% of vineyards have grass-only cover and frequent summer mowing, with only 6% sowing wildflowers. However, 60% use natural pest control, 80% reported existence of wildflowers in headlands, and 29% mentioned reduced mowing. We discuss spontaneous and sown wildflowers and benefits for biodiversity, integrated pest management and the commonly perceived barriers to adaptation. We conclude there is huge variation in management styles and more evidence-based environmental advice for viticulturists is needed

Sow Wild! Effective Methods and Identification Bias in Pollinator-Focused Experimental Citizen Science

A common debate on the value of citizen science projects is the accuracy of data collected and the validity of conclusions drawn. Sow Wild! was a hypothesis-driven citizen science project that investigated the benefits of sowing a 4 m2 mini-meadow in private gardens and allotments to attract beneficial insects. The use of researcher-verified specimen-based methods (pan traps, yellow sticky traps) and observational insect watches allowed investigation of potential bias in identification skills and sampling methods conducted by citizen scientists. For bumblebees and honeybees, identification of pan trap insect specimens was similar between researchers and citizen scientists, but solitary bees were possibly misidentified as social wasps or hoverflies. Key results of the Sow Wild! project differed between specimen-based and observation-only data sets, probably due to unconscious bias, such that incorrect conclusions may have been drawn if we had relied solely on observations made by citizen scientists without detailed training. Comparing the efficiency of sampling methods, insect watches produced the most insect observations overall. Yellow sticky traps collected more solitary wasps, social wasps, hoverflies and honeybees than pan traps. There was also variation in the abundance of insects caught according to the four pan trap colours. While all of these sampling methods can be successfully incorporated into citizen science projects to monitor a range of flying insects in urban landscapes, we recommend that verification of data by taxonomic experts is a valuable component of hypothesis-led citizen science projects, and increased training is required if target taxa include less conspicuous insect groups

Superconductivity in AuNiGe Ohmic contacts to a GaAs-based high mobility two-dimensional electron gas

To cool a high mobility two-dimensional electron gas (2DEG) at a GaAs-AlGaAs heterojunction to milliKelvin temperatures, we have fabricated low resistance Ohmic contacts based on alloys of Au, Ni, and Ge. The Ohmic contacts have a typical contact resistance of R C ≈ 0.8 ω at 4.2 K, which drops to 0.2 ω below 0.9 K. Scanning electron microscope images establish that the contacts have the same inhomogeneous microstructure that has been observed in previous studies. Measurements of the contact resistance R C, the four-terminal resistance along the top of a single contact, and the vertical resistance RV all show that there is a superconductor in the Ohmic contact, which can be turned completely normal with a magnetic field of 0.15 T. We briefly discuss how this superconductivity may be affecting the electrical transport measurements of 2DEGs, especially how it may hinder the cooling of electrons in a 2DEG below 0.1 K

The Ursinus Weekly, March 21, 1949

Dorm champs to be decided tonight: Intramural contests scheduled for 6:30 in T-G gymnasium • Editorial: Wanted, a student government • Debate team to be host for Ben Franklin tourney • Junior class picks Lanin for annual spring prom • Is our student government satisfactory? • Music, languages, coeds please Brazilian student • Med students hear talk by radiologist • Coeds battle to 25-18 win over Chestnut Hill squad • Jay Vees succumb to Chestnut Hillers in final home tilt • Baseball team starts practice sessions • Intramural season to end tomorrow; several teams tied • Quartet of cagers to finish careers in Bryn Mawr tilt • Baseball, soccer star begins tennis duties • Swimmers drop pair in week; Ellis, Borkey, Pattison get points • Sophomores choose Woody Leigh combo for April 4 dance • Clarke, Mattson thrill operetta audiencehttps://digitalcommons.ursinus.edu/weekly/1612/thumbnail.jp

Modeling the influence of the Weddell Polynya on the Filchner-Ronne Ice Shelf cavity

Open-ocean polynyas in the Weddell Sea of Antarctica are the product of deep convection, which transports Warm Deep Water (WDW) to the surface and melts sea ice or prevents its formation. These polynyas occur only rarely in the observational record, but are a near-permanent feature of many climate and ocean simulations. A question not previously considered is the degree to which the Weddell Polynya affects the nearby Filchner-Ronne Ice Shelf (FRIS) cavity. Here we assess these effects using regional ocean model simulations of the Weddell Sea and FRIS, where deep convection is imposed with varying area, location, and duration. In these simulations, the idealised Weddell Polynyas consistently cause an increase in WDW transport onto the continental shelf, as a result of density changes above the shelf break. This leads to saltier, denser source waters for the FRIS cavity, which then experiences stronger circulation and increased ice shelf basal melting. It takes approximately 14 years for melt rates to return to normal after the deep convection ceases. Weddell Polynyas similar to those seen in observations have a modest impact on FRIS melt rates, which is within the range of simulated interannual variability. However, polynyas which are larger or closer to the shelf break, such as those seen in many ocean models, trigger a stronger response. These results suggest that ocean models with excessive Weddell Sea convection may not be suitable boundary conditions for regional models of the Antarctic continental shelf and ice shelf cavities

Monitoring neonicotinoid exposure for bees in rural and peri-urban areas of the UK during the transition from pre- to post-moratorium

Concerns regarding the impact of neonicotinoid exposure on bee populations recently led to an EU-wide moratorium on the use of certain neonicotinoids on flowering crops. Currently evidence regarding the impact, if any, the moratorium has had on bees’ exposure is limited. We sampled pollen and nectar from bumblebee colonies in rural and peri-urban habitats in three UK regions; Stirlingshire, Hertfordshire and Sussex. Colonies were sampled over three years; prior to the ban (2013), during the initial implementation when some seed-treated winter-sown oilseed rape was still grown (2014), and following the ban (2015). To compare species-level differences, in 2014 only, honeybee colonies in rural habitats were also sampled. Over half of all samples were found to be contaminated (n=408), with thiamethoxam being the compound detected at the highest concentrations in honeybee- (up to 2.29 ng/g in nectar in 2014, median≤0.1 ng/g, n=79) and bumblebee-collected pollen and nectar (up to 38.77 ng/g in pollen in 2013, median ≤0.12 ng/g, n=76). Honeybees were exposed to higher concentrations of neonicotinoids than bumblebees in 2014. While neonicotinoid exposure for rural bumblebees declined post-ban (2015), suggesting a positive impact of the moratorium, the risk of neonicotinoid exposure for bumblebees in peri-urban habitats remained largely the same between 2013 and 2015