Plants and Animals

Papaipema speciosissima Regal fern borer

species photo

Key Characteristics

The Regal fern borer moth has an average wingspan of 1.8-2.0 inches (4.5 - 5.0 cm). The forewings (i.e., upper wings) are bright orange, with some brown and violet shading. It also has three white or brown, narrow vertical bars or spots; the two inner spots or bars are almost fused. The hind wings (i.e., lower wings) are orangish with slightly darker shading with a visible, light median line in the center of the hind wing.

Status and Rank

US Status: No Status/Not Listed
State Status: SC - Special Concern (rare or uncertain; not legally protected)
Global Rank: G3G4 - Rank is uncertain, ranging from vulnerable to apparently secure
State Rank: S2S3 - Rank is uncertain, ranging from imperiled to vulnerable


CountyNumber of OccurrencesYear Last Observed
Allegan 1 1995
Barry 2 2013
Cass 3 1997
Clinton 1 1997
Ingham 2 1972
Jackson 1 1988
Kalamazoo 1 2022
Lenawee 1 1982
Livingston 1 1951
St. Clair 1 2015
Wayne 1 2023

Information is summarized from MNFI's database of rare species and community occurrences. Data may not reflect true distribution since much of the state has not been thoroughly surveyed.


The Regal fern borer moth typically inhabits swamp forests but also is associated with prairie, idle/old field, lowland shrub, lowland hardwood, fen and river/stream/riparian/floodplain habitats. The larval hosts are regal and cinnamon fern (Osmundia sp.). The larvae bore into the roots of their host plant.

Specific Habitat Needs

Host plant needed in: Floodplain forestInundated shrub swampPrairie fenRich tamarack swampSouthern hardwood swampSouthern shrub-carrSouthern wet meadowWet prairieWet-mesic sand prairie.

Natural Community Types

For each species, lists of natural communities were derived from review of the nearly 6,500 element occurrences in the MNFI database, in addition to herbarium label data for some taxa. In most cases, at least one specimen record exists for each listed natural community. For certain taxa, especially poorly collected or extirpated species of prairie and savanna habitats, natural community lists were derived from inferences from collection sites and habitat preferences in immediately adjacent states (particularly Indiana and Illinois). Natural communities are not listed for those species documented only from altered or ruderal habitats in Michigan, especially for taxa that occur in a variety of habitats outside of the state.

Natural communities are not listed in order of frequency of occurrence, but are rather derived from the full set of natural communities, organized by Ecological Group. In many cases, the general habitat descriptions should provide greater clarity and direction to the surveyor. In future versions of the Rare Species Explorer, we hope to incorporate natural community fidelity ranks for each taxon.

Management Recommendations

The Regal fern borer moth is considered rare and may be imperiled in Michigan. Threats to this species include habitat loss, fragmentation and degradation due to conversion to agricultural lands; industrial, residential and/or recreational development; encroachment by invasive plants; use of pesticides and herbicides; wetland modifications; altered fire regimes; altered hydrologic regimes; and lack of scientific knowledge. Surveys are needed to determine this species' status, abundance and distribution in the state. Research to obtain more information on this species' life history and ecology and to assess threats to this species also is warranted. The sites at which this species has been documented should be protected and maintained. Adequate and suitable habitat at these sites need to be maintained including sufficient densities of the species' host plants. Maintenance and long-term preservation of the habitats with which this species is associated could include maintaining or restoring hydrologic regimes, controlling invasive species, and using management tools such as tree girdling and prescribed fire in some systems to restore natural disturbance regimes and ecological processes that help maintain these systems.

Active Period

Flight from first week of September to fourth week of October

Survey Methods

Larvae are present from May to July, boring into the roots of their host plants, regal and cinnamon fern (Osmundia sp.). In Michigan, adults have been documented from late July through October although the typical adult flight period for this species is September and October. The best way to survey for this species is by blacklighting at night during the adult flight period, a technique whereby a sheet is stretched across two trees or poles and an ultraviolet light is used to attract moths to the sheet. Insects come to light usually in largest numbers on still, dark, cloudy nights when both temperature and humidity are high. Reports of this species should be documented with a voucher specimen or a good photograph and verification by a species expert.


Survey Period: From first week of September to fourth week of October

Time of Day: Night
Humidity: Humid
Cloud Cover: Overcast
Air Temperature: Warm
Wind: No Wind
Survey Method Comment: Ideal survey conditions but surveys can be conducted during other conditions as well.


Survey References

  • Covell, Charles. A Field Guide to the Moths of Eastern North America. Peterson Field Guide Series, Houghton Mifflin Company, Boston, MA. 496 pp.
  • Martin, J.E.H. 1977. The Insects and Arachnids of Canada (Part 1): Collecting, preparing, and preserving insects, mites, and spiders. Publication 1643. Biosystematics Research Institute, Ottawa.

Technical References

  • Covell, Charles. A Field Guide to the Moths of Eastern North America. Peterson Field Guide Series, Houghton Mifflin Company, Boston, MA. 496 pp.
  • Forbes, W.T.M. 1954. Lepidoptera of New York and Neighboring States, Noctuidae, Part III. Cornell University Agricultural Experiment Station, NY. 433 pp.
  • Kost, M.A. 2001. Natural community abstract for relict conifer swamp. Michigan Natural Features Inventory, Lansing, MI. 6 pp.
  • Spieles, J.B., P.J. Comer, D.A. Albert, and M.A. Kost. 1999. Natural community abstract for prairie fen. Michigan Natural Features Inventory, Lansing, MI. 4 pp.
  • Stehr, F. W. 1997. Michigan Lepidoptera Survey Sites and Seasonal Occurrence of Michigan's Listed Species Annual Report 1997. 30 pp.+ MI Lepidoptera Survey Data Collection Form