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 Chicago on a given day, based on 367 verified sightings from GBIF citizen-science data. It is the 39th most-seen of the 978 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.
July and August
In those months about 20% of wildlife watchers report a Great Black Digger Wasp in Chicago on a given day, against under 5% in October 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.
Among the best
Of the 15 cities where we can rate Great Black Digger Wasp sightings, Chicago ranks 4th at about 10%, level with the leaders once rounded. The best odds are in Boston (United States, about 10%), Minneapolis [Saint Paul] (United States, about 10%) and Detroit (United States, about 10%).
GBIF citizen-science records
It is estimated from how often the Great Black Digger Wasp is recorded against all the insects logged in Chicago (367 verified sightings), 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.
