Vacant Lots Structure Food Webs

Does land management influence predatory arthropod communities and their roles in urban food webs?

A rare nine-spotted ladybug, Coccinella novemnotata. Photo by MaLisa Spring

Cleveland, Ohio has an increasing amount of vacant land due to economic decline and home foreclosure. Although vacant land may be seen as blight within the city, it can provide opportunities to support conservation efforts. Some of these vacant lots have recently been turned into pocket prairies, providing a new type of habitat. This research aims to quantify how habitat management and landscape context of vacant land patches influences predator species diversity and resource partitioning.

Lady beetles and long-legged flies are common insect predators within urban landscapes and can be strongly influenced by habitat change as well as provide pest suppression. Therefore, it is critical to determine how habitat and landscape variables shape the breadth of their dietary niche and resultant prey selection and the impact this has on the support of biodiversity in urban green spaces.

(photo: Denisha collecting long-legged flies.)

(photo: Denisha collecting long-legged flies.)

How is this research conducted?

This project focuses on two abundant predator families: lady beetles (Coccinellidae) and long-legged flies (Dolichopodidae) that will be collected from these treatments: treatment 1 (Urban standar, control), treatment 2 (Ohio meadow), treatment 6 (Low diversity pocket prairie), and treatment 8 (High diversity pocket prairie). Collection began in the summer of 2016 and will continue each summer through 2019. Lady beetles are collected by placing five sticky cards throughout each site. Pan traps filled with a soap water solution will be placed at each site for 4 hours to collect long-legged flies.The abundance of these insects will be quantified to see if population differs depending on treatments. 

Long-legged flies will also be collected using aspirators for molecular diet analysis to determine what prey the flies feed on and if the prey selection differs depending on the treatments of the pocket prairies.

What impact can this research have?

This project will shed light on how to solve shrinking cities problems and importance of green spaces for native insect biodiversity and identify if a habitat design influences a green space’s conservation value.

This project is lead by Denisha Parker. Denisha studies Entomology at the Ohio State University and is from Chicago, Illinois.

Denisha on the value of entomological research: 

“Studying Entomology is interesting to me because I am able to show people how the presence of insects should not be looked at as a bad thing. You can answer questions about the communities around you by looking at insects and how they react to the environment around them.”


This material is based upon work supported by the National Science Foundation under Grant No. 1253197.

Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.