Plants and Animals
Ophiogomphus howei Pygmy snaketail
Key Characteristics
Adults average 1.3 inches (3.3 cm) long. The Pygmy snaketail is very small for a snaketail. The species is bright green on the sides and top of thorax. The inner 1/2 (male) to 2/3 (female) of hindwing is yellow. The yellow abdominal top spots are all triangular and of various sizes. Segment 10 with no top spots. Legs black.
Status and Rank
US Status: No Status/Not Listed
State Status: T - Threatened (legally protected)
Global Rank: G3 - Vulnerable
State Rank: S1 - Critically imperiled
Occurrences
| County | Number of Occurrences | Year Last Observed |
|---|---|---|
| Calhoun | 1 | 2023 |
| Eaton | 1 | 2020 |
| Ingham | 1 | 2020 |
| Iron | 3 | 2014 |
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 - erosional and depositional small cold streams. Requires big rivers with high water quality and stable flow. Proximal to rapids or to surface-breaking structure such as cobble, boulder, or deadwood. Males patrol over stream riffles, flying in an undulating fashion.
Specific Habitat Needs
Sand, coarse cobble needed in: Headwater stream (1st-2nd order), riffle; Headwater stream (1st-2nd order), run; Mainstem stream (3rd-4th order), run; Mainstem stream (3rd-4th order), riffle.
Natural Community Types
- Alvar
- Bog
- Dry northern forest
- Dry southern forest
- Emergent marsh
- Headwater stream (1st-2nd order), riffle
- Headwater stream (1st-2nd order), run
- Inland lake, littoral, midwater
- Mainstem stream (3rd-4th order), run
- Mainstem stream (3rd-4th order), riffle
- Mesic northern forest
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
Habitat degradation is major threat including impoundment of rivers, poorly drained roads, channelization, toxic or organic pollution, exotic species. Larvae are especially intolerant of water conditions downstream from dams.
Survey Methods
An exuvia survey consists of searching the banks and protruding rocks of rapid streams for the cast skin of dragonfly larvae. Adults are most active during the day, disappearing in late afternoon and not reappearing till late morning the next day, peak activity is from 2:30 to 3:30 pm. Adults forage primarily in the treetops on sides of river valleys, but occasionally in riverside trees, or even on low plants in nearby fields. Males patrol with a bouncy flight over rippling water, but not over pools or rapids. Females are easier to see than males because they display their tinted hindwings by holding them vertically much of the time during flight.
Aerial net, visual survey
Survey Period: From fourth week of April to fourth week of June
Time of Day: Afternoon
Survey Method Comment: Adults
D-frame net
Survey Period: From first week of January to fourth week of December
Time of Day: Daytime
Water Level: Low Water Levels
Water Turbidity: Low Turbidity
Survey Method Comment: Larva
Exuvia survey
Survey Period: From fourth week of April to fourth week of June
Time of Day: Daytime
Survey Method Comment: Adults/Larva
References
Survey References
- 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
- Mead, K. 2003. Dragonflies of the North Woods. Kollath-Stensaas Publishing, Duluth. 203pp.
- 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.