Are neonicotinoid insecticides driving declines of widespread butterflies?

There has been widespread concern that neonicotinoid pesticides may be adversely impacting wild and managed bees for some years, but recently attention has shifted to examining broader effects they may be having on biodiversity. For example in the Netherlands, declines in insectivorous birds are positively associated with levels of neonicotinoid pollution in surface water. In England, the total abundance of widespread butterfly species declined by 58% on farmed land between 2000 and 2009 despite both a doubling in conservation spending in the UK, and predictions that climate change should benefit most species. Here we build models of the UK population indices from 1985 to 2012 for 17 widespread butterfly species that commonly occur at farmland sites. Of the factors we tested, three correlated significantly with butterfly populations. Summer temperature and the index for a species the previous year are both positively associated with butterfly indices. By contrast, the number of hectares of farmland where neonicotinoid pesticides are used is negatively associated with butterfly indices. Indices for 15 of the 17 species show negative associations with neonicotinoid usage. The declines in butterflies have largely occurred in England, where neonicotinoid usage is at its highest. In Scotland, where neonicotinoid usage is comparatively low, butterfly numbers are stable. Further research is needed urgently to show whether there is a causal link between neonicotinoid usage and the decline of widespread butterflies or whether it simply represents a proxy for other environmental factors associated with intensive agriculture

Green Exercise, Blue Spaces and Active Leisure Events: The Performance of New Participants is Associated With Their Response to Event Characteristics

Active leisure events (ALEs) promoting activity among non-traditional sporting participants are an increasingly important part of health interventions and social prescribing. Identifying characteristics of ALEs that encourage engagement are key for enhancing their efficacy. Models revealed first-time participants returned to parkrun more quickly if they were male, older, performed poorly, attended a larger event with more new adult participants, a hard surface type and with woodland and freshwater on its route. Interaction terms between performance and event characteristics revealed poor performing new participants were particularly influenced by event size and less influenced by woodland and freshwater suggesting that they might find it easier to hide at large events and feel less out of place. This highlights the importance not just of identifying characteristics of ALEs that influence return rates but also identifying interaction terms with performance so the behavior of target demographics can be better understood. Organisers of ALEs might want to consider prioritizing the use of routes that maximize exposure to woodland and freshwater and consider introducing additional strategies designed to make less fit participants feel that they belong

Extreme Promiscuity in a Mating System Dominated by Sexual Conflict

Coelopids live in wrack beds consisting of seaweed washed up on beaches. 5 Their mating system is characterized by sexual conflict and convenience 6 polyandry, with females resisting male mating attempts. We estimated the 7 level of harassment by males and the success rate of rejection by females 8 collected from a high density wild population. Males mounted a female every 9 8.41 min. Of these mounts 35% resulted in copulation. This suggests that 10 females could be mated up to 5 times every 2 h. Females typically live for 11 3 weeks, and thus, could mate with hundreds of males during their lifetime. 12 We found a 50:50 sex ratio throughout the wrack bed revealing that females 13 do not avoidmale harassment by leaving the wrack bed when not ovipositing

New Parkrunners Are Slower and the Attendance Gender Gap Narrowing Making Parkrun More Inclusive

Parkrun is a weekly mass-participation event. Finishes are recorded, with the resulting database potentially containing important public health information. The aim of this study was to identify characteristics of events that overcome barriers to participation, and to identify changing patterns in the demographics of participants. GLMMs were generated of age-graded performance, gender ratio and age of participants at Scottish parkrun events. Predictor variables included age, gender, participant, runs, date, elevation gain, surface and travelling time to the next nearest venue. There was a decline in the mean performance of participants at events, yet individual performances improved. The gender ratio showed higher male participation with a narrowing gender gap. Events in the most remote parts of Scotland had lower performance and a higher proportion of female participants. Events on slower surfaces had more female participants. Parkrun events are becoming more inclusive, with more females and participants exhibiting low performance. In more remote parts of Scotland, more females participated in parkrun than males, suggesting parkrun has overcome traditional barriers to female participation in sport. Prioritising the creation of events at remote locations and on slower surfaces could increase inclusivity further. General practitioners prescribing parkrun might want to prescribe attendance at slower events for female patients

Rapid rise in toxic load for bees revealed by analysis of pesticide use in Great Britain

A strong argument can be made that the European Union has the most rigorous regulatory system for pesticides in the world, and that modern pesticide use poses fewer environmental threats than older regimes. Nevertheless, the impacts of pesticides on bees and other non-target organisms are much debated in Europe as elsewhere. Here we document changing patterns of pesticide use in arable and horticultural crops in Great Britain from 1990 to 2015. The weight of pesticides used has approximately halved over this period, but in contrast the number of applications per field nearly doubled. The total potential kill of honeybees (the total number of LD50 doses applied to the 4.6 million hectares of arable farmland in Great Britain each year) increased six-fold to approximately 3 1016 bees, the result of the increasing use of neonicotinoids from 1994 onwards which more than offset the effect of declining organophosphate use. It is important to stress that this does not mean that this number of bees will be killed, and also to acknowledge that our simple analysis does not take into account many factors such as differences in persistence, and timing and mode of application of pesticides, which will affect actual exposure of non-target organisms. Nonetheless, all else being equal, these data suggest that the risk posed by pesticides to non-target insects such as bees, other pollinators and natural enemies of pests, has increased considerably in the last 26 years

Factors driving the decline in the publication of geocaches

Geocaching is a popular outdoor recreational pastime that uses GPS to navigate to specific coordinates where the geocacher usually has to find a hidden container. Geocaching has many benefits including promoting exercise and learning. The number of new geocaches being published has started to decline. Here I present the first analysis of what factors might be contributing to that decline. Data on the geocache placement patterns of 116 geocachers were derived using the geocaching statistics analytical tool, Project GC. Two generalised linear mixed models were conducted on the resulting dataset. The study suggested that more active participants in the game are more likely to hide geocaches. The rate of hiding of geocaches declines over time. A quadratic relationship was identified with number of caches owned which suggests that individual geocachers have limits to the number of geocaches they can maintain. Perhaps, surprisingly the study suggested that cache saturation was only having a relatively small impact compared to these other potential drivers of the decline. Individual limits on geocaches owned and reduced activity over time appear to be the key drivers of the decline. Consequently the study suggests that a continuing influx of new participants to the pastime is required to maintain high levels of geocache placements. A range of measures to make geocaching more attractive to both current and future participants is suggested, for example increasing efforts to remove abandoned geocaches, making it easier for geocachers to identify the locations of high quality geocaches and increasing the variety of geocache types by the introduction of Citizen Science geocaches. By contrast, the study suggests that relaxing the rules on cache saturation is not likely to have much of an impact upon future levels of geocache placement. Management implications This study has identified keys factors associated with the current decline in geocache placements and has identified alterations to the management of the game that could mediate some of these effects. It remains to be seen whether or not the planet will ever have 4,000,000 active geocaches. The current trajectory suggests not, however actions could be taken which could alter this trajectory. In particular this study suggests key to continue to attract new participants to the pastime. This could be done by increasing cache type variety and improving the quality of existing geocaches and the ability of geocachers to identify their locations

Exposure to the neonicotinoid imidacloprid disrupts sex allocation cue use during superparasitism in the parasitoid wasp Nasonia vitripennis

N.C., J.G., and D.M.S. were funded by Natural Environment Research Council (NERC) grant (NE/J024481/1). P.R.W. was funded by a University of Stirling Impact Fellowship.1. Neonicotinoid insecticides are potent neurotoxins of significant economic importance. However, it is clear that their use can adversely impact beneficial insects in the environment, even at low, sub-lethal doses. 2. It has recently been shown that the neonicotinoid imidacloprid disrupts adaptive sex allocation in the parasitoid wasp Nasonia vitripennis (Walker) by limiting their ability to respond to the presence of other females on oviposition patches. In the present study, that work was extended to explore whether sex allocation when superparasitising – laying eggs on a host that has already been parasitised – is also disrupted by imidacloprid. 3. Under superparasitism, sex allocation theory predicts that females should vary their offspring sex ratio in relation to their relative clutch size. It was found that sex allocation under superparasitism in Nasonia is disrupted in a dose-dependent manner, with exposed females producing more daughters. 4. Importantly, imidacloprid does not appear to influence the ability of females to estimate the number of eggs already present on a host, suggesting a disassociation between the sex ratio and clutch size cues. 5. The present work highlights the fitness costs to beneficial insects of exposure to neonicotinoids, but also provides clues as to how female Nasonia use information when allocating sex.Publisher PDFPeer reviewe

Predictors of successful return to parkrun for first-time adult participants in Scotland

Physical activity is essential for promoting good health and reducing burdens on healthcare systems. parkrun organise free weekly events where participants complete a 5km route. Studies have identified characteristics of participants associated with lower levels of participation. The aim of the study was to identify predictors of the likelihood of returning to parkrun for first-time adult participants. The return rate of adult first-time participants was determined for all 5km parkrun events in Scotland over a 1-year period from February 2019. The dataset consisted of 20,191 adult participants made up of 11,459 females and 8,732 males across 58 venues. A General Linear Mixed Model was used to identify factors associated with return rate. Return rates were negatively correlated with event size and positively correlated with the proportion of first-time adult participants at the event. Age was positively correlated with return rate and males were more likely to return. New participants that finished in a relatively slow time were disproportionately less likely to return. Return rates were positively correlated with the amount of freshwater and woodland on the route. These findings provide potential opportunities to manage events to enhance their efficacy. Specific events could be promoted as first-timer days to encourage new participants to attend together. New events could be prioritised in proximity to events that currently experience high attendances to reduce attendances locally. As the presence of freshwater and woodland are associated with higher return these habitats could play a role in generating the benefits of green exercise. If so the creation of more routes running through or alongside these habitats could be beneficial. The findings are likely to be widely applicable to other mass participation events and those interesting in understanding the mechanism by which green exercise provides its benefits

Larval exposure to the neonicotinoid imidacloprid impacts adult size in the farmland butterfly Pieris brassicae

Populations of farmland butterflies have been suffering from substantial population declines in recent decades. These declines have been correlated with neonicotinoid usage both in Europe and North America but experimental evidence linking these correlations is lacking. The potential for non-target butterflies to be exposed to trace levels of neonicotinoids is high, due to the widespread contamination of agricultural soils and wild plants in field margins. Here we provide experimental evidence that field realistic, sub-lethal exposure to the neonicotinoid imidacloprid negatively impacts the development of the common farmland butterfly Pieris brassicae. Cabbage plants were watered with either 0, 1, 10, 100 or 200 parts per billion imidacloprid, to represent field margin plants growing in contaminated agricultural soils and these were fed to P. brassicae larvae. The approximate digestibility (AD) of the cabbage as well as behavioural responses by the larvae to simulated predator attacks were measured but neither were affected by neonicotinoid treatment. However, the duration of pupation and the size of the adult butterflies were both significantly reduced in the exposed butterflies compared to the controls, suggesting that adult fitness is compromised through exposure to this neonicotinoid

New Parkrunners Are Slower and the Attendance Gender Gap Narrowing Making Parkrun More Inclusive

Parkrun is a weekly mass-participation event. Finishes are recorded, with the resulting database potentially containing important public health information. The aim of this study was to identify characteristics of events that overcome barriers to participation, and to identify changing patterns in the demographics of participants. GLMMs were generated of age-graded performance, gender ratio and age of participants at Scottish parkrun events. Predictor variables included age, gender, participant, runs, date, elevation gain, surface and travelling time to the next nearest venue. There was a decline in the mean performance of participants at events, yet individual performances improved. The gender ratio showed higher male participation with a narrowing gender gap. Events in the most remote parts of Scotland had lower performance and a higher proportion of female participants. Events on slower surfaces had more female participants. Parkrun events are becoming more inclusive, with more females and participants exhibiting low performance. In more remote parts of Scotland, more females participated in parkrun than males, suggesting parkrun has overcome traditional barriers to female participation in sport. Prioritising the creation of events at remote locations and on slower surfaces could increase inclusivity further. General practitioners prescribing parkrun might want to prescribe attendance at slower events for female patients