Plants and Animals
Eucosma bipunctella Two-spotted Eucosma
Key Characteristics
This small moth is in the family Tortricidae and has a wingspan of 3.2 to 4.3 cm. It is named for the two spots on its wings. Larvae bore into roots or may feed on other plant parts of its host, species in the Silphium genus, especially compass plant (Silphium laciniatum).
Status and Rank
US Status: No Status/Not Listed
State Status: SC - Special Concern (rare or uncertain; not legally protected)
Global Rank: GNR - Not ranked
State Rank: SNR - Not ranked
Occurrences
| County | Number of Occurrences | Year Last Observed |
|---|---|---|
| Bay | 1 | 1966 |
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
The moth is found in close association with its larval hostplant, compass plant (Silphium laciniatum; Heinrich 1923; Heppner 2003). It likely uses other Silphium species as well (Metzler et al. 2005). The larvae bore into the roots of its host plant, where it lives in a silken chamber (Metzler et al. 2005).
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
Lack of scientific knowledge about its life history is an obvious threat. Until more is known about the ecology of this moth, specific management recommendations cannot be provided at this time. Surveys and monitoring to assess the extent of this species’ distribution in Michigan are needed to assess the status of this moth in Michigan. It is likely that habitat destruction and the use of herbicides and pesticides negatively impact this species.
Active Period
Flight from fourth week of May to fourth week of August
Survey Methods
In Michigan, adults may be found from May to September, however, surveys for adults should be done in August. 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 and verification by a species expert.
Blacklighting
Survey Period: From fourth week of July to first week of September
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
- Gilligan, T.M., J. Baixeras, and J.W. Brown. 2018. T@RTS: Online World Catalogue of the Tortricidae (Ver. 4.0). http://www.tortricid.net/catalogue.asp.
- Heinrich, C. 1923. Revision of the North American moths of the subfamily Eucosminae of the family Olethreutidae. United States National Museum Bulletin 123:1-298.
- Heppner, J.B. 2003. Arthropods of Florida and Neighboring Land Areas: Lepidoptera of Florida. Florida Department of Agriculture 17(1): 1-670.
- Metzler, E.H., J. A. Shuey, L.A. Ferge, R.A. Henderson, and P.Z. Goldstein. 2005. Contributions to the Understanding of Tallgrass Prairie-Dependent Butterflies and Moths (Lepidoptera) and their Biogeography in the United States. Bulletin of The Ohio Biological Survey, New Series 15. No. 1. 143pp.