Moths and their caterpillars are often underappreciated in ecological communities, despite there being thousands more moth species compared to butterfly species in North America. Moths and caterpillars provide important ecosystem services including converting energy from plants to animals within food webs and serving as pollinators. Most species are specialists that have a limited number of host plants on which they can feed. Knowing which moth species are present at Mt. Cuba Center, particularly rare species and those with very specific host-plant requirements, helps us manage our gardens and natural lands to include plants that support them. To find out what moths we have here, Sarver Ecological conducted a survey at Mt. Cuba in 2024 and in 2025.

To determine what moths are present here, researchers set up UV lights at night in multiple locations within Mt. Cuba’s gardens and natural lands. Moths and other insects were drawn to the lights and landed on white sheets placed near them. The researches photographed the moths and other insects and posted the images to iNaturalist via Mt. Cuba Center’s Fauna Project for help with identification. iNaturalist serves as a great data repository and provides an opportunity for crowdsourcing identification, including from experts in the field. A subset of moths that were not easily identifiable from photographs were collected and sent to an expert for identification.

Mt. Cuba staff and guests also contributed their observations through the Mt. Cuba Center Fauna iNaturalist Project. Caterpillar photos from staff and guests were particularly helpful because some moth species are not attracted to lights, and finding caterpillars was a more effective way to document their presence. Doug Tallamy and his team also shared data from previous moth sampling they conducted at Mt. Cuba, contributing to the whole picture of moths present here.

At least 692 species in total have been identified to date, including 25 species that were reported for the first time in Delaware on iNaturalist. The full species list as well as the list of specialists can be found in the report. Interesting finds are described in more detail in the section on specialists organized by plant order. The report also recommends specific host plants for Mt. Cuba to cultivate to support moth populations.

There are many things people can do to promote moths at home. First and foremost, plant native plants! Whether you are practicing conservation by addition and adding native plants little by little to your existing plantings, converting large areas of lawn to gardens, meadows, or forests, or planting natives in a container, every bit counts! Consider planting keystone species that support high numbers of different caterpillars. Plant host plants for caterpillars and plants that offer nectar resources for moths. Always avoid or minimize the use of pesticides, which harm not only moths, but all of our native insects.

At night, outdoor lights can attract moths, leading them to circle and deplete their energy resources, and these lights can also attract moth predators. To minimize these impacts, turn off outdoor lights at night or use motion-detecting lights, when possible. Using outdoor lighting that points downward, LED bulbs, and warm-colored bulbs are other steps you can take to help your local moth populations.

Many moths overwinter as pupae in the leaf litter or soil. By “leaving the leaves” and/or planting native plants around the trunks of trees you can provide “soft landings” and improve moth habitat for this part of their life cycle. You can also move leaves off of lawn and into surrounding garden beds, which double as mulch.

You can learn more about key host plants and the feeding preferences of different species through Doug Tallamy’s research or David Wagner’s Caterpillars of Eastern North America: A Guide to Identification and Natural History. This book is also a great resource for identification and includes two indexes – allowing readers to search by caterpillar or by host plant. If you are interested in hosting more caterpillars in your yard, another resource that enables you to search by host plant or butterfly or moth species is the National Wildlife Federation Native Plant Finder.

Hear from the researchers themselves during our upcoming online class, Heroes of the Night: Highlights from Mt. Cuba’s Moth Study on August 12.