Aquatic Insects of Michigan
by Ethan Bright, Museum of Zoology Insect Division and School of Natural Resources and Environment
University of Michigan
- Home
- Species Lists
- Coleoptera
- Diptera
- Ephemeroptera
- Acanthametropodidae
- Ameletidae
- Ametropodidae
- Arthropleidae
- Baetidae
- Baetiscidae
- Behningiidae
- Caenidae
- Ephemerellidae
- Ephemeridae
- Heptageniidae
- Isonychiidae
- Leptohyphidae
- Leptophlebiidae
- Metretopodidae
- Neoephemeridae
- Oligoneuriidae
- Palingeniidae
- Polymitarcyidae
- Potamanthidae
- Pseudironidae
- Siphlonuridae
- Heteroptera
- Hymenoptera
- Lepidoptera
- Megaloptera
- Neuroptera (Sisyridae)
- Odonata
- Orthoptera
- Plecoptera
- Trichoptera
- Other Orders
- Keys/Identification
- Aquatic Insects of Michigan
Stenacron (Ephemeroptera: Heptageniidae)
Imagos (males only: adapted from Lewis 1974)
| 1a | Outer lateral margins of penis lobes without a cluster of large spines, although extremly minute spines may be present | Stenacron candidum (Traver) |
| also: Penis lobes with terminal or subterminal spines; black spiracular dots on Ab4-8 terga; black dashes on face below antennae | ||
| 1b | Outer lateral margins of penis lobes with a cluster of large spines | 2 |
| 2a(1b) | Lobes of penis with discal spines | Stenacron interpunctatum (Say) (in part) |
| also: no axial spine on penis lobe; apical spine of each penis lobe, if present, smaller than discal spine; either with a black streak present on pleuron ventral to fore wing base, a black dash connecting cross veins below bulla in fore wing, or with spiracular dots present | ||
| 2b | Lobes of penis with terminal or subterminal spines | 3 |
| 3a(2a) | In ventral view, abdomen with a median, longitudinal dark line extending from anterior to posterior ends, this line slightly widened and with a narrow interruption at the posterior margin of each sternum | Stenacron gildersleevei (Traver) |
| 3b | Abdomen not as above, in ventral view usually entirely pale or faint dark marks at the posterior margin of some sterna | Stenacron interpunctatum (Say) (in part) |
Mature nymphs (adapted from Lewis 1974)
| 1a | a. Each maxilla with 30 or more lateral setae | Stenacron gildersleevei (Traver) |
| b. Crown of maxilla with 11-13 heavy pectinate spines | ||
| also: sterna 7-9 without dark bands or spots | ||
| 1b | a. Each maxilla with less than 30 lateral setae | 2 |
| b. Crown of maxilla with 7-10 spines | ||
| 2a(1b) | Inner margin of outer canine of left mandible with 8 teeth | Stenacron candidum (Traver) |
| 2b | Inner margin of outer canine with 5-7 teeth | Stenacron interpunctatum (Say) |
| also: In dorsal view, pale longitudinal streaks the length of the abdomen continuous or nearly so, usually some distinct dark markings on posterior sterna; very common, widely distributed | ||
References
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Lewis PA. 1974. Taxonomy and ecology of Stenonema(it.) mayflies (Heptageniidae: Ephemeroptera). National Environmental Research Center, U.S. Environmental Protection Agency, Cincinnati, Ohio. EPA-670/4-74-006. 89 p.
Page created: November 10, 2003; Last edited: November 06, 2013 (EB)