Dimorphic jumper (Maevia inclemens)
The dimorphic jumper is a spider in the family Salticidae that is not dangerous to people. GBIF holds 1,255 licensed U.S. records of it; it reaches our listing threshold in 33 states, most of all Oklahoma (150), Texas (140) and Massachusetts (94). Its observation records peak in June.
Maevia inclemens or the dimorphic jumping spider is a relatively common and colorful jumping spider of North America. In the males there are two forms, a very rare phenomenon in zoology. These use different courting displays, and differ in appearance: the "tufted" morph has a black body and pedipalps ("palps"), three black tufts across its "head", and pale legs; and the "gray" morph has black and white stripes all over its body and legs, orange palps, and no tufts.
From Wikipedia: Maevia inclemens, text under CC BY-SA 4.0.
Is the dimorphic jumper poisonous or venomous?
Not in any medically significant way. Like almost all spiders the dimorphic jumper (family Salticidae) has venom for its prey, but it is not a widow or recluse, the two U.S. groups whose bites need medical attention.
Which states have the dimorphic jumper?
Records are spread over 33 states; the top three, Oklahoma, Texas and Massachusetts, hold 31% of them.
| # | State | Records | Share of state spiders | Rank in state |
|---|---|---|---|---|
| 1 | Oklahoma | 150 | 2.9% | 5th of 149 |
| 2 | Texas | 140 | 0.5% | 42nd of 386 |
| 3 | Massachusetts | 94 | 2.0% | 8th of 189 |
| 4 | Ohio | 92 | 1.3% | 21st of 332 |
| 5 | New York | 75 | 1.2% | 21st of 149 |
| 6 | Virginia | 59 | 0.5% | 48th of 176 |
| 7 | Minnesota | 58 | 1.9% | 12th of 145 |
| 8 | Pennsylvania | 58 | 0.8% | 27th of 164 |
| 9 | Michigan | 55 | 2.3% | 9th of 122 |
| 10 | Illinois | 54 | 0.3% | 54th of 243 |
| 11 | Indiana | 48 | 1.1% | 17th of 133 |
| 12 | Maryland | 47 | 0.8% | 36th of 153 |
| 13 | North Carolina | 37 | 0.4% | 55th of 184 |
| 14 | Kentucky | 30 | 1.6% | 17th of 103 |
| 15 | New Jersey | 25 | 1.1% | 25th of 127 |
| 16 | Wisconsin | 23 | 0.7% | 33rd of 149 |
| 17 | Missouri | 21 | 0.9% | 23rd of 117 |
| 18 | Connecticut | 20 | 2.0% | 13th of 86 |
| 19 | West Virginia | 20 | 2.6% | 8th of 90 |
| 20 | Louisiana | 18 | 0.4% | 42nd of 107 |
| 21 | Alabama | 17 | 0.5% | 54th of 143 |
| 22 | New Hampshire | 17 | 1.2% | 24th of 72 |
| 23 | Kansas | 14 | 0.9% | 22nd of 94 |
| 24 | Maine | 14 | 1.5% | 17th of 297 |
| 25 | Tennessee | 13 | 0.3% | 57th of 138 |
| 26 | Florida | 12 | 0.1% | 129th of 237 |
| 27 | Georgia | 11 | 0.2% | 91st of 186 |
| 28 | Arkansas | 10 | 0.6% | 41st of 114 |
| 29 | Rhode Island | 8 | 4.7% | 4th of 53 |
| 30 | South Carolina | 6 | 0.3% | 64th of 121 |
| 31 | Nebraska | 4 | 0.3% | 51st of 71 |
| 32 | Iowa | 1 | 0.1% | 50th of 57 |
| 33 | Delaware | 0 | — | — |
When is the dimorphic jumper seen?
Across the U.S., observation records of the dimorphic jumper run mostly March through September, peaking in June with 30% of them. Winter (December to February) holds 2% of them.
Season by state
Among states whose main season falls within one calendar year, it starts earliest in March (Kentucky, Maryland, New York, Oklahoma and Texas) and latest in May (Minnesota). The most common peak month is June, shared by Massachusetts, Michigan, Minnesota, New York, Pennsylvania and Texas.
| State | Main season | Peak month | Observation records |
|---|---|---|---|
| Oklahoma | March through September | April | 147 |
| Texas | March through September | June | 139 |
| Massachusetts | April through August | June | 94 |
| Ohio | April through September | May | 88 |
| New York | March through September | June | 75 |
| Virginia | April through August | May | 59 |
| Minnesota | May through August | June | 57 |
| Michigan | April through August | June | 55 |
| Pennsylvania | April through September | June | 48 |
| Maryland | March through July | May | 47 |
| Kentucky | March through August | April | 30 |
Where the dimorphic jumper is recorded in each state
Oklahoma
Oklahoma holds 150 licensed records, the 5th most recorded of 149 spiders listed there. Its observation records in Oklahoma run mostly March through September, peaking in April; most licensed records come from Osage County, Mayes County and Tulsa County. Next come Pawnee County (10) and Cleveland County (8).
Texas
Texas holds 140 licensed records, the 42nd most recorded of 386 spiders listed there. Its observation records in Texas run mostly March through September, peaking in June; most licensed records come from Dallas County, Tarrant County and Travis County. Next come Collin County (4) and Denton County (4).
Massachusetts
Massachusetts holds 94 licensed records, the 8th most recorded of 189 spiders listed there. Its observation records in Massachusetts run mostly April through August, peaking in June; most licensed records come from Middlesex County, Worcester County and Dukes County. Next come Norfolk County (6) and Barnstable County (6).
Ohio
Ohio holds 92 licensed records, the 21st most recorded of 332 spiders listed there. Its observation records in Ohio run mostly April through September, peaking in May; most licensed records come from Montgomery County, Franklin County and Lucas County. Next come Hamilton County (7) and Clermont County (5).
New York
New York holds 75 licensed records, the 21st most recorded of 149 spiders listed there. Its observation records in New York run mostly March through September, peaking in June; most licensed records come from Westchester County, Dutchess County and Nassau County. Next come Putnam County (6) and Rockland County (6).
Virginia
Virginia holds 59 licensed records, the 48th most recorded of 176 spiders listed there. Its observation records in Virginia run mostly April through August, peaking in May; most licensed records come from Goochland County, Prince William County and Fairfax County. Next come Powhatan County (4) and Buckingham County (3).
Minnesota
Minnesota holds 58 licensed records, the 12th most recorded of 145 spiders listed there. Its observation records in Minnesota run mostly May through August, peaking in June; most licensed records come from Hennepin County, Anoka County and Ramsey County. Next come Washington County (3) and Dakota County (2).
Pennsylvania
Pennsylvania holds 58 licensed records, the 27th most recorded of 164 spiders listed there. Its observation records in Pennsylvania run mostly April through September, peaking in June; most licensed records come from Westmoreland County, Allegheny County and Monroe County. Next come Montgomery County (5) and Chester County (3).
Michigan
Michigan holds 55 licensed records, the 9th most recorded of 122 spiders listed there. Its observation records in Michigan run mostly April through August, peaking in June; most licensed records come from Washtenaw County, Ingham County and Charlevoix County. Next come Midland County (4) and Kalamazoo County (3).
Illinois
Illinois holds 54 licensed records, the 54th most recorded of 243 spiders listed there. Most of its licensed records in Illinois come from Cook County, Champaign County and Jo Daviess County. Next come DuPage County (5) and Mason County (4).
Indiana
Indiana holds 48 licensed records, the 17th most recorded of 133 spiders listed there. Most of its licensed records in Indiana come from Lake County, Morgan County and Johnson County. Next come Porter County (3) and Monroe County (2).
Maryland
Maryland holds 47 licensed records, the 36th most recorded of 153 spiders listed there. Its observation records in Maryland run mostly March through July, peaking in May; most licensed records come from Frederick County, Howard County and Montgomery County. Next come Allegany County (2) and Baltimore County (2).
North Carolina
North Carolina holds 37 licensed records, the joint 55th most recorded of 184 spiders listed there. Most of its licensed records in North Carolina come from Orange County, Cleveland County and Swain County. Next come Wake County (3) and Yancey County (2).
Kentucky
Kentucky holds 30 licensed records, the 17th most recorded of 103 spiders listed there. Its observation records in Kentucky run mostly March through August, peaking in April; most licensed records come from Shelby County, Jefferson County and Madison County. Next come Campbell County (2) and Edmonson County (2).
Top counties in the U.S.
| # | County | State | Records | Share of U.S. |
|---|---|---|---|---|
| 1 | Dallas County | Texas | 88 | 7.0% |
| 2 | Osage County | Oklahoma | 51 | 4.1% |
| 3 | Mayes County | Oklahoma | 44 | 3.5% |
| 4 | Middlesex County | Massachusetts | 40 | 3.2% |
| 5 | Frederick County | Maryland | 32 | 2.5% |
| 6 | Hennepin County | Minnesota | 28 | 2.2% |
| 7 | Westchester County | New York | 25 | 2.0% |
| 8 | Lake County | Indiana | 24 | 1.9% |
| 9 | Tulsa County | Oklahoma | 24 | 1.9% |
| 10 | Montgomery County | Ohio | 21 | 1.7% |
| 11 | Westmoreland County | Pennsylvania | 16 | 1.3% |
| 12 | Goochland County | Virginia | 16 | 1.3% |
| 13 | Franklin County | Ohio | 13 | 1.0% |
| 14 | Washtenaw County | Michigan | 11 | 0.9% |
| 15 | Anoka County | Minnesota | 11 | 0.9% |
How recent are the dimorphic jumper records?
Most of what is known about the dimorphic jumper is recent: 87% of dated U.S. records were made in 2017–2026, and half date from 2022 or later. The oldest dated record is from 1928; the busiest year was 2026, with 246 records.
| Decade | Records | Share |
|---|---|---|
| 1920s | 1 | 0.1% |
| 1930s | 8 | 0.6% |
| 1940s | 8 | 0.6% |
| 1950s | 7 | 0.5% |
| 1960s | 9 | 0.7% |
| 1970s | 3 | 0.2% |
| 1980s | 5 | 0.4% |
| 1990s | 7 | 0.5% |
| 2000s | 7 | 0.5% |
| 2010s | 283 | 21.7% |
| 2020s | 969 | 74.1% |
Species recorded in the same counties
Of the 189 counties where the dimorphic jumper is most recorded, 125 are also top counties for the bold jumper, more than for any other spider. None of its closest neighbors is venomous.
| Species | Shared counties |
|---|---|
| Bold jumper | 125 |
| Nursery web spider | 118 |
| Familiar jumping spider | 114 |
| Flea jumping spider | 108 |
| Spined micrathena | 106 |
| Dark fishing spider | 105 |
| Orchard orbweaver | 103 |
| Parson spider | 100 |
Related species in the U.S.
Other members of the family Salticidae with profiles here: Bold jumper, Familiar jumping spider, Zebra spider, Bronze jumper, Magnolia green jumper and Half-edged wall jumping spider.
GBIF records read 2026-09-29. Listed: any license. Counted: CC0/CC BY only. How we count.