Establishment of Wildflower Islands to Enhance Roadside Health and Aesthetics

Wildflowers are crucial in the ecological function of the low-input roadside plant communities in terms of water andnutrient cycling, nutrient inputs such as nitrogen, total plant canopy cover, stand longevity, and provision of habitat for numerous small animals. Further, wildflowers provide critical foraging and nesting resources for birds, insects, and other wildlife. Unfortunately, habitat loss from agricultural and urban development has led to rapid population declines in wild bees and other pollinators across the US, thereby jeopardizing not only food production but also the sustainability of our natural landscapes (Kearns & Inouye, 1997). One way to mitigate wild bee decline is to establish more habitat corridors on public rights-of-way, such as roadsides. Planting pollinator-friendly native wildflowers on roadsides provides nutrient-rich forage and nesting resources for bees and is aesthetically pleasing. With 97,256 miles of public roadways in Nebraska (~4 million miles of roadways in the United States), roadsides play ever increasing roles in sustaining biodiversity within our state and beyond. Federal guidelines state that wildflowers are to be used in roadside seeding mixtures, and NDOT includes a diversity of wildflower species in its seeding mixtures. However, these complex seeding mixtures are often expensive because of the diversity of species and high seed price of many of these native species, particularly the wildflowers which compose roughly 10% of the total seeds but represent 30% of the total cost of seed mixtures. Further, wildflowers on roadsides are typically seeded with competitive grasses and are costly to establish and manage long term. This research explored ways to improve wildflower establishment by separating wildflower seeds from the conventional seed mixture with includes both wildflower and grass seeds. Additionally, wildflower plots were seeded at different patch or island sizes to assess cost-effective ways of reducing competition by nonnative weeds and enhancing the longevity of roadside habitat. Optimal patch sizes and treatment groups included 100% wildflower mix seeded to the entire 3 m x 18.3 m plot (treatment 100), only 50% of the plot seeded in one continuous patch (treatment 50) or in two small patches (treatment 25x2) compared to current practices of seeding wildflower-grass mixtures (treatment conventional). Ecological benefits of roadside habitat, wild bee abundance, diversity, and nesting activity was assessed and compared across seeding practices and patch size treatments. Floral diversity and abundance were also analyzed to compare plant-pollinator interactions across treatments. Conventional roadside seeding methods yielded plots with lower abundance and richness of forbs and bees compared to plots seeded with wildflowers only (treatments 100, 50, 25x2) but only in the first year of establishment. Bee richness was highest in the late season, while forb abundance and richness were highest in the mid-season. No differences were observed across differently sized wildflower-only patches likely because of the recent establishment of plots. In fact, only ~50% of seeded forbs had established and roughly 14 plants out of the 40 species in the seed mixture did not establish in either survey years and may therefore be replaced in future seed mixtures. Our results indicate that wildflower segregation in strips or islands may be a cost-effective method of improving wildflower establishment and persistence in diverse roadside mixtures. As plots mature and become vulnerable to weed encroachment, the effect of patch size may become more distinguished across treatment groups, therefore, further monitoring and research may be necessary to further address issues with low establishment and high competitive pressure from volunteer species. This data contributes to NDOT’s ongoing pursuit to more effectively establish wildflowers on roadsides and to better understand the role floral enhancements have on supporting and sustaining vulnerable wildlife, such as our pollinator communities

Why some countries thrive despite corruption : the role of trust on the corruption-efficiency relationship

Author's OriginalWhile it is widely accepted that corruption negatively affects economic growth, why some countries achieve rapid growth under rampant corruption remains a puzzle. We shed light on this issue by examining the role of trust in the corruption-efficiency relationship. We argue that in countries with a relatively high level of trust, corruption tends to be more "efficiency enhancing" than corruption in countries with a relatively low level of trust, which tends to be more "predatory" and thus, inefficient. To illustrate our arguments, we first conduct a qualitative comparative case study of China and the Philippines. We then further subject our ideas to a quantitative test using a pooled data set of 65 countries in two time periods. Both our case study and statistical test support our general hypothesis that trust mitigates the negative effect of corruption on economic growth.Li, S., & Wu, J. (2010). Why some countries thrive despite corruption: The role of trust in the corruption-efficiency relationship. Originally presented at the Academy of International Business U.S. Northeast Chapter Regional Meeting, Portsmouth, New Hampshire. Subsequently published in Review of International Political Economy, 17(1), 129-154. doi:10.1080/0969229080257744

Effects of neonicotinoid imidacloprid exposure on bumble bee (Hymenoptera: Apidae) queen survival and nest initiation

Neonicotinoids are highly toxic to insects and may systemically translocate to nectar and pollen of plants where foraging bees may become exposed. Exposure to neonicotinoids can induce detrimental sublethal effects on individual and colonies of bees and may have long-term impacts, such as impaired foraging, reduced longevity, and reduced brood care or production. Less well-studied are the potential effects on queen bumble bees that may become exposed while foraging in the spring during colony initiation. This study assessed queen survival and nest founding in caged bumble bees [Bombus impatiens (Cresson) (Hymenoptera: Apidae)] after chronic (18-d) dietary exposure of imidacloprid in syrup (1, 5, 10, and 25 ppb) and pollen (0.3, 1.7, 3.3, and 8.3 ppb), paired respectively. Here we show some mortality in queens exposed at all doses even as low as 1 ppb, and, compared with untreated queens, significantly reduced survival of treated queens at the two highest doses. Queens that survived initial imidacloprid exposure commenced nest initiation; however, they exhibited dose-dependent delay in egg-laying and emergence of worker brood. Furthermore, imidacloprid treatment affected other parameters such as nest and queen weight. This study is the first to show direct impacts of imidacloprid at field-relevant levels on individual B. impatiens queen survival and nest founding, indicating that bumble bee queens are particularly sensitive to neonicotinoids when directly exposed. This study also helps focus pesticide risk mitigation efforts and highlights the importance of reducing exposure rates in the early spring when bumble bee queens, and other wild bees are foraging and initiating nests

Sub-lethal effects of dietary neonicotinoid insecticide exposure on honey bee queen fecundity and colony development

Many factors can negatively affect honey bee (Apis mellifera L.) health including the pervasive use of systemic neonicotinoid insecticides. Through direct consumption of contaminated nectar and pollen from treated plants, neonicotinoids can affect foraging, learning, and memory in worker bees. Less well studied are the potential effects of neonicotinoids on queen bees, which may be exposed indirectly through trophallaxis, or food-sharing. To assess effects on queen productivity, small colonies of different sizes (1500, 3000, and 7000 bees) were fed imidacloprid (0, 10, 20, 50, and 100 ppb) in syrup for three weeks. We found adverse effects of imidacloprid on queens (egg-laying and locomotor activity), worker bees (foraging and hygienic activities), and colony development (brood production and pollen stores) in all treated colonies. Some effects were less evident as colony size increased, suggesting that larger colony populations may act as a buffer to pesticide exposure. This study is the first to show adverse effects of imidacloprid on queen bee fecundity and behavior and improves our understanding of how neonicotinoids may impair short-term colony functioning. These data indicate that risk-mitigation efforts should focus on reducing neonicotinoid exposure in the early spring when colonies are smallest and queens are most vulnerable to exposure. Includes Supplementary Information

Sub-lethal effects of dietary neonicotinoid insecticide exposure on honey bee queen fecundity and colony development

Many factors can negatively affect honey bee (Apis mellifera L.) health including the pervasive use of systemic neonicotinoid insecticides. Through direct consumption of contaminated nectar and pollen from treated plants, neonicotinoids can affect foraging, learning, and memory in worker bees. Less well studied are the potential effects of neonicotinoids on queen bees, which may be exposed indirectly through trophallaxis, or food-sharing. To assess effects on queen productivity, small colonies of different sizes (1500, 3000, and 7000 bees) were fed imidacloprid (0, 10, 20, 50, and 100 ppb) in syrup for three weeks. We found adverse effects of imidacloprid on queens (egg-laying and locomotor activity), worker bees (foraging and hygienic activities), and colony development (brood production and pollen stores) in all treated colonies. Some effects were less evident as colony size increased, suggesting that larger colony populations may act as a buffer to pesticide exposure. This study is the first to show adverse effects of imidacloprid on queen bee fecundity and behavior and improves our understanding of how neonicotinoids may impair short-term colony functioning. These data indicate that risk-mitigation efforts should focus on reducing neonicotinoid exposure in the early spring when colonies are smallest and queens are most vulnerable to exposure. Includes Supplementary Information