By: Ash Lloyd, EcoHouse Green Gardening Volunteer
The Mottled Duskywing
The Mottled Duskywing (Erynnis martialis) could easily be mistaken for a moth due to its brown mottled colouring and wing profile, but it is actually a butterfly from the Hesperiidae family, commonly known as “Skippers”. They are relatively small, having an average wingspan of only between 25 – 29 mm, so they are often harder to spot than the larger, more familiar monarchs and swallowtails. Between mid-May to late August, the mottled duskywing usually produces two generations each year.
Relationship with New Jersey Tea & Prairie Redroot
The plant known as New Jersey tea (Ceanothus americanus) is of special importance to the Mottled Duskywing,serving as a host plant and a food source for the butterfly’s larval stage. The native shrub can be found across the northeastern parts of Turtle Island (North America) and also serves as a food source for the spring and summer azure butterflies as well as the dreamy duskywing. In Ontario, the Mottled Duskywing will only deposit its eggs on a New Jersey tea plant or the closely related Prairie Redroot. This means the butterfly will not reproduce if these plants are absent. Thus, it’s particularly important that both plant species be protected to save the Mottled Duskywing from extinction.
The habitat of the Mottled Duskywing is unlike most butterflies. Rather than lush meadows, it prefers sandy and barren patches of earth. They are known to be particularly fond of formations known as “alvars”, which are areas with sparse vegetation and exposed, underlying limestone deposits. This can partly be attributed to the fact that both host plants, New Jersey tea and Prairie Redroot, also favour this habitat
Like most threatened species, the number one threat to the Mottled Duskywing is human beings. Constantly expanding urban development, spraying for invasive gyspy moths, and introducing jack pines are all contributing factors to the butterfly’s current endangered status. It does not help that its preferred habitat is not visually appealing to most laypeople and does not have the same charisma of a forest or meadow of flowing grass and flowers. Right now, all the known sites of the Mottled Duskywing have some basic level of protection, but the constant development of land that is not “productive” leaves its future uncertain.
What can be done?
If you find yourself wanting to do something to help save this unassuming little butterfly, there are a number of things you can do. Firstly, you can plant New Jersey tea and/or Prairie Redroot in any garden you own or have access to. Secondly, you can organize with other concerned citizens and petition the part of your community’s government responsible for parks. Making sure they include both plants as they stock public lands. You can also learn how to identify the butterfly at its different life stages and report any sightings or suspected nesting spots in your area, to help them get the protection they deserve.