Scouting Urban Insects

Insect Trap Atop the US Bank Tower in Los Angeles, Ca
Photo: MAYA SUGARMAN/KPCC

Humans alter the urban landscape with buildings including tall skyscrapers. Skyscrapers made of steel and concrete are new habitats that could be colonized by plants, insects and other organisms. Skyscrapers have steep vertical sides and can offer different microclimates than the surrounding area. What lives up there?

Scientists from the Natural History Museum of Los Angeles County are studying insects that are present on the rooftop of the tallest skyscraper in the Western United States. Moths and flies have already been observed on top of the tower. What else lives there? We will know more when the project is finished.

Urban rooftops can provide multiple unique habitats depending on how they are managed. Increasing interest in energy conservation has led to the establishment of green roofs. One of our undergraduates surveyed the insects present on a green roof installed on the Purdue Campus. Most of the plants on the roof are low growing, too short to harbor larger insects. However, the green roof is home for many of the soil dwelling insects and arthropods common on the soils below. A green roof is less sterile than the typical steel and concrete or membrane covered roof.

Should we think of our urban rooftops as places to be managed as habitat for urban wildlife? Is this a good idea? What are the risks and potential benefits. As the world becomes increasingly urban, more people are considering these questions.