Transforming urban vacant land for agriculture production has been on the rise since the 1890s. Cities that have experienced economic decline that results in an overabundance of vacant land, such as Cleveland, OH, are continuing the trend of urban agriculture. Currently, Cleveland has over 20,000 vacant lots and 235 of these sites have been converted to urban farms and community gardens which address worldwide issues of food security.
However, as urban farmers try to address food security issues, they are faced with the decline in beneficial insects species, such as native lady beetles. These species are needed for the success of agriculture. Since the 1980s researchers have noticed a decline in native lady species which correlates with the introduction of exotic species. The majority of research focused on native lady beetle decline has centered around direct competition, intraguild predation, by exotic species however, if has not been proven in field studies. Exploitative competition, competition for shared resources, is another form of competition that can explain native species decline but it is highly understudied. This form of competition suggest that when exotic lady beetle species reduce a prey base, native lady beetle species will abandon a habitat to forage elsewhere. This implies that the surrounding landscape is likely to affect the supply of beneficial insects. Therefore, I propose to test exploitative competition between native and exotic lady beetle species in order to understand how the composition and management of vacant land influences these dietary interactions among native and exotic lady beetles. My project aims to utilize next generation sequencing tools to: 1)Examine how local habitat management and large-scale landscape composition influences lady beetle abundance and diversity within vacant lots and urban agroecosystems, and 2) measure the dietary breadth and overlap among lady beetle species within vacant lots and urban farms to determine if resource partitioning predicts species diversity within a habitat and how these habitats vary in their ability to support native lady beetle conservation. In short term, my project will contribute to research on conservation of native lady beetle in urban areas. Long term, my project will inform urban farmers and city land managers on the best ways to revitalize urban green space to benefit native lady beetle species that in turn can provide success in urban farms. This will provide economic success in urban cities which can support healthier urban environments and encourage productive urban agriculture.
The long-term goal for my research is to demonstrate if competition with exotic lady beetles explains the decline of native lady beetle species and use this information to design urban habitats to support native lady beetle communities and the biological control they provide to urban agriculture. By the end of the project, urban farmers and Cleveland officials will learn (1) what species of native and exotic lady beetles are found in urban greenspaces and agroecosystems and 2) if competition for food among native and exotic species results in native species declines. A key action outcome will be a factsheet detailing how urban farmers and land managers can take action to conserve native species and their ecosystem services by modifying existing habitats to provide needed alternative prey and other necessary resources.
To distribute knowledge regarding learning and action outcomes I will produce an extension fact sheet, publish a peer-reviewed scientific publication, and start a blog dedicated to educating readers on the importance of native lady beetles and what can be done to increase their presence. I will also educate owners of urban farms about land management that can be incorporated in their farms to promote an increase in native lady beetle species which in return can promote success in their farms.
Abundance and Richness
- Lady beetles were sampled within 24 sites within eight Cleveland, Ohio, USA neighborhoods. Within each neighborhood, three sites were assigned to the habitat treatments: Control, High-Diversity Prairie, and Urban-Garden. Control sites consisted of a turf grass and mown once per month. High-Diversity Prairie sites consist of sixteen native prairie forbs and four prairie grasses.
- Prior to data collection, we established a 7 m x 15 m within the center of each site. The plot was divided into 1m2 quadrats, and all vegetation and lady beetle data was collected from within this grid.
- Monthly sampling took place during June – August.
- Lady beetles were collected using no-bait yellow sticky card traps. Five traps were deployed in each site, with one trap placed in each corner of the 7 x 15 meter plot, and one located in the center. The cards were attached to stakes at vegetation height, and remained in the field for 7 days, after which they were brought into the laboratory and identified to species.
- Within each sited 10 native and 10 exotic lady beetles were hand collected using aspirator, vacuum, and/or sweep net
- All samples where rinsed in 10% bleach solution then individually placed in ethanol and stored in freezer until analysis begin.
- We hand collected a total of 214 lady beetles for molecular analysis
- DNA extractions are underway
- Exotic lady beetles dominated the total number of lady beetles captures using sticky traps
- Statical analysis are underway to determine how lady beetle communities differed across treatments
Educational & Outreach Activities
2018: I callaborated with Cleveland’s Green Corps of youth farmers to develop a workshop on insect biodiversity in urban farms. During this workshop we constructed different stations that included; 1) learning insect taxonomy, 2) learning how to pin insects, 3) learning how to collect insects, and finally 4) a scavenger hunt that aided in teaching how to identify common plants and insects that occur in urban farms. Involved in this outreach event were Katie Turo (another NCR SARE recipient) and our two mentored undergraduates, who helped design our workshop stations.
I also travel to Innsbruck, Austria to learn how to do molecular techniques in order to determine diet overlap in urban farms and vacant lots in Cleveland.