Snakes and spiders in Riley County, Kansas
Riley County, home of Manhattan, has 17 snake and 12 spider species on record, from 420 licensed snake and 84 spider records. Venomous species here: the eastern copperhead and the brown recluse.
Are there venomous snakes or spiders in Riley County?
Yes. The eastern copperhead: 23 licensed records, 4% of all Kansas records of it. The brown recluse: 6 licensed records, 7% of all Kansas records of it.
What snakes are in Riley County?
In all, 17 snake species are on the Riley County list. The most recorded are the ring-necked snake (108), the eastern racer (40) and the northern water snake (36).
| # | Species | Records | Share of Kansas records |
|---|---|---|---|
| 1 | Ring-necked snake Diadophis punctatus | 108 | 4% |
| 2 | Eastern racer Coluber constrictor | 40 | 5% |
| 3 | Northern water snake Nerodia sipedon | 36 | 3% |
| 4 | Flathead snake Tantilla gracilis | 24 | 3% |
| 5 | Eastern copperhead venomous Agkistrodon contortrix | 23 | 4% |
| 6 | Western rat snake Pantherophis obsoletus | 23 | 5% |
| 7 | Common garter snake Thamnophis sirtalis | 22 | 3% |
| 8 | DeKay's brown snake Storeria dekayi | 16 | 5% |
| 9 | Gopher snake Pituophis catenifer | 15 | 2% |
| 10 | Great Plains rat snake Pantherophis emoryi | 15 | 6% |
| 11 | Eastern milksnake Lampropeltis triangulum | 11 | 4% |
| 12 | Corn snake Pantherophis guttatus | 10 | 8% |
| 13 | Western worm snake Carphophis vermis | 10 | 4% |
| 14 | Plains garter snake Thamnophis radix | 7 | 1% |
| 15 | Central plains milksnake Lampropeltis gentilis | 6 | 3% |
| 16 | Lined snake Tropidoclonion lineatum | 6 | 1% |
| 17 | Speckled kingsnake Lampropeltis holbrooki | 6 | 2% |
When are snakes out in Riley County?
Observation records of snakes in Riley County run mostly April through September, peaking in May with 35% of them, the same peak as Kansas as a whole.
What spiders are in Riley County?
In all, 12 spider species are on the Riley County list. The most recorded are the bold jumper (11), the brilliant jumping spider (9) and the brown recluse (6).
| # | Species | Records | Share of Kansas records |
|---|---|---|---|
| 1 | Bold jumper Phidippus audax | 11 | 11% |
| 2 | Brilliant jumping spider Phidippus clarus | 9 | 33% |
| 3 | Brown recluse venomous Loxosceles reclusa | 6 | 7% |
| 4 | Familiar jumping spider Platycryptus undatus | 6 | 7% |
| 5 | Triangulate bud spider Steatoda triangulosa | 6 | 23% |
| 6 | Black-and-yellow argiope Argiope aurantia | 5 | 6% |
| 7 | Rabid wolf spider Rabidosa rabida | 4 | 11% |
| 8 | Spotted orbweaver Neoscona crucifera | 4 | 11% |
| 9 | Furrow orbweaver Larinioides cornutus | 2 | 7% |
| 10 | Striped lynx spider Oxyopes salticus | 2 | 7% |
| 11 | Banded garden spider Argiope trifasciata | 1 | 3% |
| 12 | Dark fishing spider Dolomedes tenebrosus | — | — |
When are spiders out in Riley County?
Observation records of spiders in Riley County run mostly May through October, peaking in August with 28% of them, the same peak as Kansas as a whole.
Common in Kansas, not on the Riley County list
Among the snakes most recorded across Kansas, these do not reach the county list: the western massasauga (490 statewide) and the prairie rattlesnake (347 statewide). Few records here can mean the species is rare in the county, or that few people have looked.
Among the spiders most recorded across Kansas, these do not reach the county list: the spined micrathena (38 statewide) and Paraphidippus aurantius (37 statewide). Few records here can mean the species is rare in the county, or that few people have looked.
Harmless lookalikes in Riley County
Copperheads are on the county list, and so are harmless species often taken for them: the northern water snake, the eastern milksnake, the corn snake and the central plains milksnake. No cottonmouths reach the county list, but the northern cottonmouth is on the Kansas list: treat any snake like it as venomous until identified. Harmless species often taken for them here: the northern water snake. No rattlesnakes reach the county list, but the western massasauga, the prairie rattlesnake and the timber rattlesnake are on the Kansas list: treat any snake like them as venomous until identified. Harmless species often taken for them here: the gopher snake and the Great Plains rat snake. No coral snakes reach the county list, and GBIF holds no coral snake record for Kansas under any license, so one reported here is most likely a harmless lookalike: the eastern milksnake and the central plains milksnake. No widow spiders reach the county list, but the western black widow, the northern black widow and the southern black widow are on the Kansas list: treat any spider like them as venomous until identified. Harmless species often taken for them here: the triangulate bud spider.
Riley County among Kansas counties
By licensed snake records Riley County ranks 7th of 105 Kansas counties with any.
Other Kansas counties with their own page: Cowley County, Douglas County, Chase County, Ellis County, Russell County, Cherokee County, Barber County and Johnson County.
The whole state: venomous species in Kansas, all snakes, all spiders.
GBIF records read 2026-09-29. Listed: any license. Counted: CC0/CC BY only. How we count.