Plants and Animals
Stylurus laurae Laura's snaketail
Key Characteristics
Total length of 2.4 - 2.6 inches (6.1-6.5 cm). The head is greenish-yellow with a distinct black cross stripe on the face. The dark middorsal thoracic stripe widens anteriorly isolating a pale, smoothly rounded, stripe, that is nearly but not confluent with the pale collar. The antehumeral and humeral stripes are separated by a thin, often interrupted, pale line between them. The rest of the thorax is yellowish green with the remaining lateral stripes present and complete, although the midlateral stripe may be lacking at its lower end. The legs are pale basally becoming black distally. There is a nearly complete yellow middorsal stripe on abdominal segments 1-7.
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: S3 - Vulnerable
Occurrences
| County | Number of Occurrences | Year Last Observed |
|---|---|---|
| Allegan | 2 | 2002 |
| Barry | 1 | 1997 |
| Berrien | 1 | 2023 |
| Branch | 1 | 2023 |
| Calhoun | 1 | 2023 |
| Eaton | 1 | 2022 |
| Genesee | 1 | 2000 |
| Gladwin | 1 | 1997 |
| Hillsdale | 1 | 2022 |
| Ingham | 4 | 2022 |
| Jackson | 3 | 2022 |
| Kalamazoo | 2 | 1997 |
| Kent | 1 | 2023 |
| Lenawee | 1 | 2023 |
| Livingston | 5 | 2022 |
| Macomb | 2 | 2018 |
| Mecosta | 2 | 2022 |
| Monroe | 2 | 2022 |
| Montcalm | 1 | 2023 |
| Oakland | 1 | 2016 |
| Ogemaw | 1 | 1997 |
| Shiawassee | 2 | 2022 |
| St. Joseph | 1 | 2016 |
| Washtenaw | 4 | 2022 |
| Wayne | 2 | 2015 |
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
Lotic - depositional. Well established in sandy-bottomed streams. Adults appear in river/stream/riparian/floodplain corridor. Shallow, well shaded, rivers and streams with cobble, sand or mud substrate. Clean streams with sand-mud bottoms.
Specific Habitat Needs
Sandy substrate needed in: Headwater stream (1st-2nd order), run.
Natural Community Types
- Headwater stream (1st-2nd order), riffle
- Headwater stream (1st-2nd order), run
- Mainstem stream (3rd-4th order), run
- Mainstem stream (3rd-4th order), riffle
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
Species is sensitive to continued decrease in water quality. Also affected by impoundments, channelization, dredging, siltation, non-point pollution (agricultural), and industrial pollution. Timber harvests may increase siltation and cause a decrease in dissolved oxygen.
Survey Methods
An exuvia survey consists of searching the banks and protruding rocks of rapid streams for the cast skin of dragonfly larvae. Forages from leaves along forest edges. Males perch mostly on leaves overhanging water, but also briefly on rocks and logs. They arrive at water about 10 am but are most active after 6 pm.
Aerial net, visual survey
Survey Period: From fourth week of May to first week of October
Time of Day: Afternoon
Survey Method Comment: Adults
D-frame net, Dip net
Survey Period: From first week of January to first week of December
Time of Day: Daytime
Water Level: Low Water Levels
Water Turbidity: Low Turbidity
Survey Method Comment: Larvae
Exuvia survey
Survey Period: From first week of June to first week of October
Time of Day: Daytime
Survey Method Comment: Adults/Larvae
References
Survey References
- Foster, S.E. and D.A. Soluk. 2004. Evaluating exuvia collection as a management tool for the federally endangered Hine's emerald dragonfly, Somatochlora hineana Williamson (Odonata: Cordulidae). Biological Conservation 118: 15-20.
- 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
- Dunkle, S.W. 2000. Dragonflies through Binoculars. Oxford University Press, Oxford. 266pp.
- Louton, J.A. 1982. Lotic dragonfly (Anisoptera: Odonoata) nymphs of the Southeastern United States: identification, distribution, and historical biogeography. A Dissertation, The University of Tennessee, Knoxville. 357pp.
- Merritt, R.W. and K.W. Cummins. 1996. An introduction to the aquatic insects of North America, 3rd ed. Kendall/Hunt Publishing Company, Dubuque. 862pp.
- NatureServe. 2005. NatureServe Explorer: An online encyclopedia of life [web application]. Version 4.5. NatureServe, Arlington, Virginia. Available http://www.natureserve.org/explorer