Plants and Animals

Euxoa immixta Mixed Dart Moth

Key Characteristics

The forewing length of this moth ranges from 1.5 to 1.8 cm. This species can be identified by the buff or brown forewing, the punctiform outer element of the postmedial line, and the darker hindwing (Lafontaine 1987). Until recently, details of the larval stages and host plant of this species were unknown (Lafontaine 1987). However, it was recently documented in Wisconsin on a remnant prairie where it was observed from larvae to adults.  These observations confirmed that the larvae consume wild wormwood (Artemisia campestris; Fraxinus Natural History Blog 2018).

Status and Rank

US Status: No Status/Not Listed
State Status: SC - Special Concern (rare or uncertain; not legally protected)
Global Rank: G4 - Apparently secure
State Rank: SNR - Not ranked

Occurrences

CountyNumber of OccurrencesYear Last Observed

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.

Habitat

While little is known of this species, it will likely be found in close association with its host plant, wild wormwood (Artemisia campestris). It is possible that it feeds on other species as well.

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

It is likely that habitat destruction is a leading threat to this moth. Lack of scientific knowledge about its life history is an obvious threat. Until more is known about the ecology of this species, specific management recommendations cannot be provided at this time. Surveys and monitoring to assess the status and extent of this species’ distribution in Michigan are needed.

Active Period

Flight from first week of June to first week of August

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 specimen vouchers or verification by a species expert with a clear photo.

Blacklighting

Survey Period: From first week of June to fourth week of July

Time of Day: Night
Humidity: Humid
Cloud Cover: Overcast
Air Temperature: Above 60 degrees
Wind: No Wind
Survey Method Comment: Here we present ideal conditions, however surveys can be conducted during other conditions as well.

References

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

  • Lafontaine, J.D. 1987. Noctuoidea: Noctuidae (part) Moths of America North of Mexico, Fascicle 27.2:81 pp