Sphex pensylvanicus
In 3 days ~30% in a week ~50%
Sphex pensylvanicus, the great black wasp or great black digger wasp, is a species of digger wasp. It lives across most of North America and grows to a size of 20–35 mm (0.8–1.4 in). The larvae feed on living insects that the females paralyze and carry to the underground nest.
S. pensylvanicus is distributed across most of the contiguous United States and northern Mexico. During the late 20th century, its range expanded north to New York and the Canadian provinces of Quebec and Ontario. Sphex pensylvanicus is a large, black wasp, significantly larger than their congener Sphex ichneumoneus (the great golden digger wasp). Males are smaller than females, at only 19–28 mm (0.7–1.1 in) long compared with typical female sizes of 25–34 mm (1.0–1.3 in). According to John Bartram, "The sting of this Wasp is painful, but does not swell like others". As well as being larger than S. ichneumoneus, they are also darker, with an entirely black body and smoky wings with a blue iridescence, where S. ichneumoneus has yellow wings, red legs, and a partly red abdomen.
Adult females of S. pensylvanicus build an underground nest which they... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Acadia National Park | 🇺🇸 United States | |
| 2 | Shenandoah National Park | 🇺🇸 United States | |
| 3 | Great Smoky Mountains National Park | 🇺🇸 United States |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Boston | 🇺🇸 United States | |
| 2 | Minneapolis [Saint Paul] | 🇺🇸 United States | |
| 3 | Detroit | 🇺🇸 United States | |
| 4 | Chicago | 🇺🇸 United States | |
| 5 | New York City | 🇺🇸 United States | |
| 6 | Toronto | 🇨🇦 Canada | |
| 7 | Philadelphia | 🇺🇸 United States | |
| 8 | Montreal | 🇨🇦 Canada | |
| 9 | Dallas | 🇺🇸 United States | |
| 10 | Washington | 🇺🇸 United States |
With luck
About 10% of wildlife watchers report a Great Black Digger Wasp sighting in Acadia National Park on a given day, based on 31 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 93rd most-seen of the 405 insects we can rate there. Over three days the chance rises to about 30%, and over a week to about 50%, if each day is a fresh chance.
August
In that month about 20% of wildlife watchers report a Great Black Digger Wasp in Acadia National Park on a given day, against under 5% in November to June, the lowest months.
Between 1 and 4 pm
Across all the parks we cover, that three-hour window holds the most Great Black Digger Wasp sightings with a recorded time, and nearly all of them come between 6 am and 6 pm: it is a daytime animal.
Yes
Of the 3 parks where we can rate Great Black Digger Wasp sightings, Acadia National Park has the highest daily chance: about 10%. Next come Shenandoah National Park (United States, under 5%) and Great Smoky Mountains National Park (United States, under 5%).
GBIF citizen-science records
It is estimated from how often the Great Black Digger Wasp is recorded against all the insects logged in Acadia National Park (31 verified sightings from 2019 to 2026), calibrated against known sighting rates. Figures are rounded to the nearest 10% because citizen-science data supports honest approximations, not decimals, and months with records from fewer than five people show "—". How it works.
