Seneca County
Known species: 57
Total Observations: 1,086
Population: 55,914
Area in Square Miles: 551
People per Square Mile: 101
Observations per Square Mile: 1.8
Percent of State Species: 33%
Percent of State Observations: 0.4%
County iNaturalist observations
The Observed Species table provides statistical data on all odonata species that have been observed in the county. Below that is a Target Species table listing species that have not yet been documented in this county, but are likely to exist in the county. This list is data-driven by listing species records from neighboring counties.
Observed Species
Common Name | Scientific Name | Seneca Total | Ohio Total | Seneca 2024 | Last Sighted |
|---|---|---|---|---|---|
| Common Whitetail | Plathemis lydia | 117 | 12,022 | 22 | 2024 |
| Blue-fronted Dancer | Argia apicalis | 98 | 6,584 | 3 | 2024 |
| Eastern Forktail | Ischnura verticalis | 97 | 15,992 | 18 | 2024 |
| Eastern Amberwing | Perithemis tenera | 71 | 10,887 | 7 | 2024 |
| Violet Dancer | Argia fumipennis violacea | 69 | 7,557 | 7 | 2024 |
| Fragile Forktail | Ischnura posita | 57 | 13,199 | 18 | 2024 |
| Familiar Bluet | Enallagma civile | 50 | 6,173 | 3 | 2024 |
| Blue Dasher | Pachydiplax longipennis | 49 | 15,601 | 7 | 2024 |
| Blue-tipped Dancer | Argia tibialis | 35 | 4,492 | 5 | 2024 |
| Widow Skimmer | Libellula luctuosa | 32 | 11,931 | 4 | 2024 |
| Powdered Dancer | Argia moesta | 32 | 5,141 | 3 | 2024 |
| Blue-ringed Dancer | Argia sedula | 32 | 2,837 | 0 | 2023 |
| Orange Bluet | Enallagma signatum | 31 | 3,791 | 2 | 2024 |
| Twelve-spotted Skimmer | Libellula pulchella | 29 | 3,740 | 1 | 2024 |
| Eastern Pondhawk | Erythemis simplicicollis | 27 | 16,365 | 6 | 2024 |
| Double-striped Bluet | Enallagma basidens | 26 | 5,343 | 7 | 2024 |
| Ebony Jewelwing | Calopteryx maculata | 26 | 8,606 | 0 | 2023 |
| Stream Bluet | Enallagma exsulans | 20 | 4,803 | 1 | 2024 |
| Slender Spreadwing | Lestes rectangularis | 20 | 3,904 | 0 | 2022 |
| Band-winged Meadowhawk | Sympetrum semicinctum | 18 | 931 | 0 | 2023 |
| Autumn Meadowhawk | Sympetrum vicinum | 16 | 8,456 | 0 | 2023 |
| Dusky Dancer | Argia translata | 14 | 1,681 | 0 | 2022 |
| American Rubyspot | Hetaerina americana | 13 | 4,444 | 0 | 2023 |
| Fawn Darner | Boyeria vinosa | 12 | 519 | 0 | 1988 |
| Calico Pennant | Celithemis elisa | 8 | 3,194 | 0 | 2022 |
| Westfall's Slender Bluet | Enallagma traviatum westfalli | 7 | 2,367 | 5 | 2024 |
| Prince Baskettail | Epitheca princeps | 7 | 2,788 | 2 | 2024 |
| Common Green Darner | Anax junius | 6 | 5,160 | 2 | 2024 |
| Black Saddlebags | Tramea lacerata | 6 | 3,380 | 2 | 2024 |
| Skimming Bluet | Enallagma geminatum | 4 | 3,832 | 1 | 2024 |
| Azure Bluet | Enallagma aspersum | 4 | 2,488 | 0 | 2006 |
| Wandering Glider | Pantala flavescens | 4 | 1,523 | 0 | 2023 |
| Ruby Meadowhawk | Sympetrum rubicundulum | 4 | 965 | 0 | 2018 |
| Unicorn Clubtail | Arigomphus villosipes | 3 | 2,065 | 3 | 2024 |
| Shadow Darner | Aeshna umbrosa | 3 | 1,187 | 1 | 2024 |
| Rainbow Bluet | Enallagma antennatum | 3 | 485 | 1 | 2024 |
| Blue-faced Meadowhawk | Sympetrum ambiguum | 3 | 1,452 | 0 | 2018 |
| Turquoise Bluet | Enallagma divagans | 3 | 918 | 0 | 2023 |
| Emerald Spreadwing | Lestes dryas | 3 | 567 | 0 | 2018 |
| Great Blue Skimmer | Libellula vibrans | 3 | 501 | 0 | 2022 |
| Cyrano Darner | Nasiaeschna pentacantha | 3 | 321 | 0 | 2023 |
| Painted Skimmer | Libellula semifasciata | 2 | 1,208 | 1 | 2024 |
| Citrine Forktail | Ischnura hastata | 2 | 962 | 0 | 2022 |
| Flag-tailed Spinyleg | Dromogomphus spoliatus | 2 | 809 | 0 | 2023 |
| Royal River Cruiser | Macromia taeniolata | 2 | 598 | 0 | 2022 |
| Southern Spreadwing | Lestes australis | 2 | 284 | 0 | 2019 |
| Slaty Skimmer | Libellula incesta | 1 | 4,920 | 1 | 2024 |
| Lancet Clubtail | Phanogomphus exilis | 1 | 1,803 | 1 | 2024 |
| Carolina Saddlebags | Tramea carolina | 1 | 1,263 | 0 | 2019 |
| Swift River Cruiser | Macromia illinoiensis | 1 | 760 | 0 | 2022 |
| Swamp Darner | Epiaeschna heros | 1 | 715 | 0 | 2022 |
| Spot-winged Glider | Pantala hymenaea | 1 | 562 | 0 | 2018 |
| Pronghorn Clubtail | Phanogomphus graslinellus | 1 | 503 | 0 | 1991 |
| Cobra Clubtail | Gomphurus vastus | 1 | 471 | 0 | 1937 |
| White-faced Meadowhawk | Sympetrum obtrusum | 1 | 305 | 0 | 2017 |
| Plains Clubtail | Gomphurus externus | 1 | 236 | 0 | 1990 |
| River Bluet | Enallagma anna | 1 | 20 | 0 | 2023 |
Target Species
Target species are potential County Records - species not yet documented in the county. 'Local Obs' is Local Observations and indicates the number of times that the species has been observed in adjacent counties since 2000, and '# of Counties' is the number of adjacent counties in which those recent observations took place. Zero local observations or recent counties means the existing records are historical. 'Peak Active' is a relative description of when the species has been known to fly.| Common Name | Scientific Name | Ohio Obs | Local Obs | # of Counties | Peak Active |
|---|---|---|---|---|---|
| Halloween Pennant | Celithemis eponina | 4,187 | 113 | 6 | Jul |
| Dot-tailed Whiteface | Leucorrhinia intacta | 1,702 | 71 | 6 | early Jun |
| Common Baskettail | Epitheca cynosura | 874 | 28 | 6 | late May-early Jun |
| Sweetflag Spreadwing | Lestes forcipatus | 514 | 26 | 5 | Jul-Aug |
| Swamp Spreadwing | Lestes vigilax | 608 | 20 | 4 | Jul |
| Great Spreadwing | Archilestes grandis | 959 | 19 | 4 | Sep |
| Comet Darner | Anax longipes | 605 | 18 | 4 | mid Jun-mid Jul |
| Vesper Bluet | Enallagma vesperum | 922 | 15 | 4 | Jun |
| Mocha Emerald | Somatochlora linearis | 202 | 15 | 4 | late Jun-late Aug |
| Four-spotted Skimmer | Libellula quadrimaculata | 295 | 14 | 4 | Jun |
| Lyre-tipped Spreadwing | Lestes unguiculatus | 210 | 13 | 4 | Jun-Jul |
| Midland Clubtail | Gomphurus fraternus | 927 | 88 | 3 | late May-mid Jun |
| Elegant Spreadwing | Lestes inaequalis | 580 | 23 | 3 | Jun |
| Spotted Spreadwing | Lestes congener | 860 | 11 | 3 | late Aug-late Sep |
| Macromia Hybrid | Macromia pacifica x taeniolata | 100 | 10 | 3 | late Jul-mid Aug |
| Sedge Sprite | Nehalennia irene | 396 | 7 | 3 | Jun |
| Gilded River Cruiser | Macromia pacifica | 88 | 6 | 3 | late Jul |
| Slender Baskettail | Epitheca costalis | 24 | 5 | 3 | late May |
| Aurora Damsel | Chromagrion conditum | 576 | 7 | 2 | late May-early Jun |
| Spatterdock Darner | Rhionaeschna mutata | 396 | 5 | 2 | Jun |
| Dusky Clubtail | Phanogomphus spicatus | 258 | 4 | 2 | early Jun |
| Ashy Clubtail | Phanogomphus lividus | 1,009 | 2 | 2 | late May-early Jun |
| Amber-winged Spreadwing | Lestes eurinus | 706 | 2 | 2 | Jun-Jul |
| Dragonhunter | Hagenius brevistylus | 589 | 2 | 2 | mid Jun |
| Swift Setwing | Dythemis velox | 447 | 55 | 1 | Jul-Aug |
| Handsome Clubtail | Gomphurus crassus | 209 | 13 | 1 | late May-early Jun |
| Eastern Red Damsel | Amphiagrion saucium | 1,420 | 8 | 1 | late May-early Jun |
| Rapids Clubtail | Phanogomphus quadricolor | 377 | 6 | 1 | Jun |
| Wabash River Cruiser | Macromia wabashensis | 25 | 2 | 1 | Aug |
| Spangled Skimmer | Libellula cyanea | 1,197 | 1 | 1 | Jun |
| Blue Corporal | Ladona deplanata | 601 | 1 | 1 | May |
| Clamp-tipped Emerald | Somatochlora tenebrosa | 217 | 1 | 1 | Aug |
| Arrowhead Spiketail | Zoraena obliqua | 189 | 1 | 1 | late May-early Jun |
| Variegated Meadowhawk | Sympetrum corruptum | 149 | 1 | 1 | Apr-Sep |
| Red Saddlebags | Tramea onusta | 146 | 1 | 1 | Jun-Jul |
| Golden-winged Skimmer | Libellula auripennis | 45 | 1 | 1 | late Jun |
| Skillet Clubtail | Gomphurus ventricosus | 26 | 1 | 1 | Jun |
| Black-shouldered Spinyleg | Dromogomphus spinosus | 671 | 0 | 0 | Jun-Jul |
| Russet-tipped Clubtail | Stylurus plagiatus | 390 | 0 | 0 | Sep |
| Springtime Darner | Basiaeschna janata | 374 | 0 | 0 | May |
| Lance-tipped Darner | Aeshna constricta | 361 | 0 | 0 | Sep |
| Marsh Bluet | Enallagma ebrium | 66 | 0 | 0 | mid Jun |
| Russet-tipped Clubtail | Stylurus plagiatus | 307 | 0 | 0 | Sep |
| Springtime Darner | Basiaeschna janata | 298 | 0 | 0 | May |
| Marsh Bluet | Enallagma ebrium | 66 | 0 | 0 | mid Jun |
The Columbus Escarpment cuts diagonally across Seneca County from the NE corner to the lower 1/3 of the western border. The area above this geological feature is within the Maumee Lake Plains area of the Huron-Erie Lake Plains ecoregion, which was the location of the now mostly-drained and channelized Black Swamp. The area south of this line are within the Till Plains ecoregion. The Sandusky River flows north through the county (see Sandusky River and Sandusky Bay Tributaries Watersheds). The county is entirely within the Lake Erie Watershed (See p. 11 in Ohio Coastal Atlas: Chapter 2 for a detailed watershed map).
County Observation Activity
This graph shows the total number of odonata observations for the county in blue, with the average for all Ohio counties in orange. The season is divided into 10 or 11 day segments by Month – basically early-month, mid-month, and late-month.
Page updated 3 January 2025