Date of Graduation
12-2024
Document Type
Dissertation
Degree Name
Doctor of Philosophy in Agricultural, Food and Life Sciences (PhD)
Degree Level
Graduate
Department
Entomology and Plant Pathology
Advisor/Mentor
Joshi, Neelendra K.
Committee Member
Naithani, Kusum J.
Second Committee Member
Biddinger, David J.
Third Committee Member
Szalanski, Allen L.
Keywords
Beneficial Insects; Biodiversity; Community Ecology; Foraging Biology & Behavior; Habitat Restoration; Pollinators
Abstract
Insects provide important pollination services in wild plant communities and in commercially cultivated, pollinator-dependent, high-value crops. A diversity of pollinator species provides higher rates of pollination and therefore, higher yields. Recently, populations of managed honey bees have been declining due to multiple interactive factors, and the cost of renting honey bee hives has increased significantly. In crops like tree fruits, many growers have shifted from renting bees to relying exclusively on wild pollinators. Therefore, conserving pollinator habitat adjacent to farms is gaining interest among growers. While bees are the most efficient pollinators, an assemblage that includes non-bees, such as; wasps, beetles, butterflies, moths, and flies, increases the overall pollination rates. Floral resources also support beneficial insects such as predators or parasitoids of pests that reduce the frequency and quantity of pesticide applications. More research is needed to optimize the design and management of pollinator resources. Most research being done on this is taking place in Europe. Very few studies have been conducted in the United States. Even less attention has been given to non-bee pollinators and other beneficial insects.
With the aim of learning more about plant and bee community dynamics to improve the design and function of restored floral resources, this study includes three primary objectives: (1) To assess the impact of twelve-year old pollinator plantings by analyzing the data set of bees collected from these plots every week during the foraging season, to determine if there are temporal trends in bee abundance and diversity. And, to survey the plants in these restored habitats to see how the plant community has changed over time. (2) To analyze the distribution of functional traits in this bee community; including tongue lengths, foraging ranges, nesting guilds, dietary specificity, sociality, emergence seasonality, and phylogenetic relatedness. (3) To determine the visitation rates of bees, non-bee pollinators, and other beneficial insects to specific native plant species to assess their utility for inclusion in seed mixes.
The findings from Objective 1 reveal that, despite predicted population fluctuations, the bee community has maintained a stable ratio of common to rare species and shows an upward trend in both abundance and diversity over time. Concurrently, over half of the plant community has shifted to volunteer native species, which predominantly bloom later in the bee foraging season. The findings from Objective 2 revealed notable variations in proboscis lengths and foraging ranges, driven by factors such as; bee phylogenetic relationships, nesting behaviors, dietary preferences, social structures, and foraging phenology. Understanding these variations offers insights into functional trait distribution in bee communities, guiding floral resource design and management to support diverse bee populations and enhance ecosystem stability and pollination services. The findings from Objective 3 showed variation in insect species visitation abundance and diversity across all plant species. These findings highlight the value of studying insect preferences for native plants at both species and group levels, strengthening our understanding of ecosystem interactions. Such research informs conservation efforts, guiding restoration projects to prioritize plants that support diverse and ecologically significant insect populations.
Citation
Stemet, L. (2024). Assessing Restored Pollinator Habitat to Establish Optimal Design and Management Recommendations for Wild Pollinator Diversity and Abundance. Graduate Theses and Dissertations Retrieved from https://scholarworks.uark.edu/etd/5610
