Catocala illecta
Magdalen underwing

Key Characteristics

The Magdalen underwing has a wingspan of 2.4-2.8 inches (6-7 cm). The forewing is pale gray with thin black lines. The hind wing is deep yellow with two wavy, black bands, consisting of an outer band along the outer margin of the hind wing and an inner band located about halfway into the hind wing. The underside of the forewing and inner third of the hind wing is light yellow, while the underside of the rest of the hind wing is light gray. The caterpillar is whitish and finely transversely striped with black.

Status and Rank

  • State Status: SC
  • State Rank: S2S3
  • Global Rank: G5


County NameNumber of OccurrencesYear Last Observed
Distribution map for Catocala illecta

Updated 5/15/2018. 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 Magdalen underwing is found in floodplain forests and other lowland forest and lowland shrub habitats where its host plant, honey locust (Gleditsia triacanthos), grows. This species also may feed on leadplant (Amorpha canescens) at least in other parts of its range. Little is known about this species' life history and ecology.

Specific Habitat Needs

Host plant needed in Southern hardwood swamp, Floodplain forest, Southern shrub-carr

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.


Little is known about the status, life history and ecology of this species. Incompatible natural resource management and the use of herbicides and pesticides are potential threats to this species. Lack of scientific knowledge about this species is an obvious threat. Because so little is known about this species and its status, life history and ecology, specific management recommendations can not be provided at this time. The sites at which this species has been documented should be protected and managed appropriately including maintaining healthy, viable populations of the host plant, honey locust (Gleditsia triacanthos). Surveys and monitoring to assess the status, extent and viability of known extant populations are needed. Surveys to find additional populations and determine the status, abundance and distribution of this species in the state also are warranted. Research to obtain additional information on the species' life history and ecology and assess threats to the species also is crucial.

Active Period

Flight from fourth week of June to fourth week of July

Survey Methods

The best way to survey for this species is by blacklighting, a technique where a sheet is stretched across two trees or poles and an ultraviolet light is used to attract moths to the sheet. Moths can be collected directly from the sheet. Insects come to light usually in largest numbers on still, dark, cloudy nights when both temperature and humidity are high. This species is difficult to identify in the wild. It is strongly recommended that observations of this species be verified through actual specimen vouchers or verification by a species expert.

Page Citation

Michigan Natural Features Inventory. 2007. Rare Species Explorer (Web Application). Available online at [Accessed Sep 25, 2018]


Survey References

Technical References

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