Pollination provided by bees is a critical ecosystem service for agricultural production. However, bee populations are at risk from stressors such as habitat loss, pesticides, and disease. On-farm wildflower plantings is one mitigation strategy to provide habitat and resources for bees. In many instances, government programs can subsidize the installation of these plantings for private landowners. Semi-natural habitat (SNH) in the landscape is also important for bee conservation and may alter the effectiveness of wildflower plantings. In this study, we tested the effectiveness of wildflower plantings and interactions with SNH in the landscape for promoting bee abundance and richness. Bee surveys were conducted over 2 yr at 22 sites in eastern Virginia and Maryland. Wildflower plantings, averaging 0.22 ha in size, were installed and maintained by cooperators at 10 of the sites. In total, 5,122 bees were identified from 85 species. Wildflower plantings did not alter bee communities independently, but bee abundance was greater on farms with plantings and 20–30% SNH in the landscape. Bee abundance and richness had nonlinear responses to increasing SNH in the landscape. The positive effects for richness and abundance peaked when SNH was approximately 40% of the landscape. Similar to predictions of the intermediate-landscape complexity hypothesis, increases in bee abundance at wildflower sites were only detected in simplified landscapes. Results indicate that small wildflower plantings in the Mid-Atlantic U.S. only provided conservation benefits to bee communities under specific circumstances on the scale studied, and that conserving SNH across the landscape may be a more important strategy.

Planting wildflowers is a commonly suggested measure to conserve pollinators. While beneficial for pollinators, plots of wildflowers may be inadvertently performing an ecosystem disservice by providing a suitable habitat for arthropod disease vectors like ticks. The lone star tick, Amblyomma americanum (L.), is a medically important tick species that might be able to utilize wildflower plantings as a suitable habitat. In this two-year study, ticks were sampled using dry ice baited traps from wildflower plots, weedy field margins, and forested areas to determine if wildflower plantings were increasing the on-farm abundance of A. americanum. Abiotic and biotic environmental variables were also measured to better understand which factors affect A. americanum abundance. We found no more A. americanum in wildflower plots than in weedy field margins. Forested areas harbored the greatest number of A. americanum sampled. The height of the vegetation in the sampled habitats was a significant factor in determining A. americanum abundance. Depending on the sampled habitat and life stage, this relationship can be positive or negative. The relationship with vegetation height may be related to the behavior of the white-tailed deer and the questing success of A. americanum. Overall, wildflower plots do not pose an increased risk of exposure to A. americanum on farms.