Supporting Royal Silkworm Moths in Maryland

Luna Moth by Tim Ray (Maryland Natural Resource Photo Contest)

Did you know? Over 2,600 species of moths can be found in Maryland! While large, showy species like the Luna Moth are often thought about, Maryland moths are extremely diverse, and many are very small (aka micro moths). Moths serve different ecological roles such as pollinating plants and feeding other organisms like birds. In addition, some moth species like the invasive gypsy moth can be pests.

Like butterflies, moths undergo complete metamorphosis. Females lay eggs on plants known as host plants which the caterpillars will feed upon when they hatch. Some moth species have specific host plants while others are generalists that feed upon a variety of plants. After feeding and undergoing several molts, the moth caterpillars will make a cocoon for their pupal stage. Moth cocoons are wrapped in silk. Once metamorphosis has completed, the moth pupa may remain stationary (in diapause) until changes in light, temperature, chemicals, and/or hormones trigger the adult to emerge. In some moth species, the adults lack mouthparts and are unable to feed.

Royal Silkworm Moths (Family Saturniidae)

One showy family of moths in Maryland is the Royal Silkworm Moth family (Saturniidae). Over fifteen species of Saturniids can be found in Maryland, all of which do not feed as adults.  Help give these moths a backyard boost by planting host plants for them to enjoy in your garden.

List compiled by Ashley Stubbs using Butterflies and Moths of North America site

Hickory horned-devil is the caterpillar of the royal moth. It is one of the largest caterpillars in our region by Virginia Arboretum CC by ND 2.0

In addition to planting host plants for these moths, consider the following actions to assist with supporting these moths:

• Leave the leaves. Leaf litter helps replenish soil nutrients and provides overwintering habitat for a number of beneficial invertebrates. If you cannot leave leaves throughout the yard, consider creating a leaf pile or adding leaves to compost. Because leaf litter also can serve as tick habitat, it is best to remove thick leaf litter between late March and mid-June in areas where people and pets frequent. Tick predators like wolf spiders also need the leaf cover.
• Consider creating a wood pile for overwintering butterflies and moths. Leave the wood in contact with the ground to encourage decay. Place wood near late-season nectar plants and/or host plants. The larger diameter wood pieces often are the most valuable, but smaller diameter twigs can also be used. Fast rot woods include elm, pine and sweetgum, while slow rot woods includes hickory, maple and oak. Each type of wood provides different benefits. Because wood piles also attract snakes and other wildlife, they should be placed away from house foundations.
• Ditch the fall garden cleanup. Besides leaving leaves, consider leaving standing flower and grass stalks in your garden. Sometimes, these stalks harbor cocoons or pupal cases from local insects like native bees. Remove plants in the spring. Be careful with pruning shrubs and trees that may also host cocoons. These areas also provide winter shelter and food for birds. Generally, by the time the grass needs its first cut in the spring, the pollinators have emerged. One exception: if plants are diseased, then it’s usually best to prune and discard cuttings to prevent harboring pests that may hinder next year’s growth.
• Sow seeds and plan out next year’s garden. You don’t have to plan everything all at once! Start small and grow your habitat over time. Check out our pollinator page for additional ideas.

Another way you can help local moths is to educate others on their importance and to submit sightings to places like iNaturalist. You can also participate in National Moth Week which is often held in mid-July.

Io Moth by Judy Gallagher CC by 2.0

Happy Summer HabiChat fans!

Wow! What an emergence for Brood X! While I enjoyed the periodical cicadas for the most part, I am happy to have a bit of reprieve from the noise. 

In addition to Brood X, we also have been receiving reports of sick birds around the region. Since the initial reports in May, the reports have come in from Maryland, Washington, D.C., Virginia, Pennsylvania, Ohio, and Kentucky. At this time, not much is known and we are suggesting people temporarily cease feeding birds until more is known about the causative agent and how it spreads. Please see the USGS Interagency statement for more information. For Maryland residents, if you encounter sick or dead birds, please contact the DNR/USDA Wildlife Services hotline (877-463-6497) or (410-349-8130) for those with numbers outside of Maryland. If you must remove dead birds, place them in a sealable plastic bag to dispose of with household trash. Additional information will be shared as diagnostic results are received. 

This issue is a bit bittersweet. After almost ten years of writing for HabiChat and running the Wild Acres program, I will be heading out to work on new initiatives. I have very much enjoyed working with backyard wildlife habitat enthusiasts across Maryland and hope you continue to work on creating wildlife friendly spaces! The Wild Acres program and HabiChat newsletter will still be available. 

In this summer issue, learn a little more about the beautiful and often overlooked rosy maple moth as well as other royal silkworms in Maryland. In addition, black walnut is our native plant featured this month. This species supports several species of royal silkworm moths as well as more than 100 other butterfly and moth species. With the summer heat and rains, our wild turtles are also on the move, so you can read about how to give local box turtles a boost in your backyard.

Happy Habitats,

Kerry Wixted

Click here to have HabiChat—the quarterly backyard wildlife habitat newsletter from the Wild Acres program—delivered right to your inbox!

In this Issue

• Native Animal Profile: Rosy Maple Moths
• Native Plant Profile: Black Walnut
• Habitat Tips: In Our Hands: Giving Local Box Turtles a Boost