Skip to Main Content
 

Global Search Box

 
 
 
 

ETD Abstract Container

Abstract Header

Drivers of Predatory Insect Distribution in Urban Greenspaces

Abstract Details

2021, Doctor of Philosophy, Ohio State University, Entomology.
The majority of the human population resides in cities. This transformation to an urbanized world has disrupted many species due to habitat disturbance, alien species colonization, and changes in soil and air quality. This reality has raised concerns about the impact of urbanization on insect communities. Many cities are implementing conservation efforts to combat these stressors by transforming habitats to urban farms, pocket prairies, and rain gardens. Although urbanization is a negative driver of insect biodiversity, opportunities exist to implement conservation strategies in “legacy cities” that can support insects and allow us to understand how challenges of urbanization affect their distribution patterns. Legacy cities are cities that have faced significant population decline due to the fall of manufacturing industries. This has resulted in an increase in vacant land that can be revitalized to target key conservation initiatives. My research was focused on how urban habitat transformation affects predatory insects and their community assembly, distribution patterns, and diet. I used lady beetles (Coccinellidae) and long-legged flies (Dolichopodidae) as my target species due to previous evidence illustrating their decline and importance as biological control agents. My key objectives were to determine how the local management and landscape context of urban greenspaces influenced the abundance, richness, and health of these predators. To examine their health, I focused on their ability to locate prey as well as their dietary breadth. In Chapter 1, I found that habitat type had no effect on native lady beetle abundance while local variables within a site such as plant height, biomass and bloom abundance supported a greater richness of lady beetle species. Also, I found that landscape variables such as decreased impervious surface surrounding a site and sites that were surrounded by less isolated greenspace patches supported a greater abundance and richness in lady beetles. In Chapter 2, I found that lady beetle abundance was greater in vacant lots that had been transformed to urban agroecosystems and within urban farms that were surrounded by increased proportions of greenspace and less isolated greenspace patches. Local features such as bloom richness and plant available nitrogen had a negative effect on lady beetle abundance while pollution within a site had a positive effect on lady beetles within urban farms. In Chapter 3, I found that long-legged fly abundance was greater within vacant lots compared to pocket prairies. We also found that local and landscape variables within a site such as increased impervious surface, patch isolation, bloom abundance and plant height resulted in decreased dietary breadth. In Chapter 4, I found that dominant exotic lady beetle predators have a wide dietary breadth in urban landscapes and their prey frequency and dietary breath were influenced by habitat fragmentation and landscape variables within a habitat. Overall, my work showed that the surrounding urban landscape plays an important role in predatory species distributions and diet. Findings also shed light on how habitat transformation and management shape lady beetle and long-legged fly communities. Conservation efforts should focus on the placement and management of urban conservation habitats. However, habitat transformation type should also be targeted to benefit particular species groups.
Mary Gardiner (Advisor)
Michel Andrew (Committee Member)
Megan Meuti (Committee Member)
Carol Anelli (Committee Member)
131 p.

Recommended Citations

Citations

  • Parker, D. M. (2021). Drivers of Predatory Insect Distribution in Urban Greenspaces [Doctoral dissertation, Ohio State University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=osu1619126809030714

    APA Style (7th edition)

  • Parker, Denisha. Drivers of Predatory Insect Distribution in Urban Greenspaces . 2021. Ohio State University, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=osu1619126809030714.

    MLA Style (8th edition)

  • Parker, Denisha. "Drivers of Predatory Insect Distribution in Urban Greenspaces ." Doctoral dissertation, Ohio State University, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=osu1619126809030714

    Chicago Manual of Style (17th edition)