Macrodactylus subspinosus
In 3 days ~20% in a week ~40%
Macrodactylus subspinosus is a North American beetle of the family Scarabaeidae. The members of its genus are known as "rose chafers", not to be confused with the European rose chafer, Cetonia aurata. M. subspinosus occurs from Eastern Canada to Colorado and is considered a pest of many crops and flowers. It is given its common name of rose chafer because it eats the leaves of roses, although it also feeds on many other plants.
The rose chafer has a yellowish-tan coloured body that is about 8–13 millimetres (0.3–0.5 in) in length, with wings that do not completely cover the abdomen. The beetle has six long, spiny, reddish-brown legs that gradually become darker towards the end of the appendage. It has two short lamellate antennae that end in a club of flat plates and it has chewing mouthparts. Rose chafers are covered in dull yellow hairs which give the body its characteristic colour, however with age and with normal activity the hairs are worn off the head and thorax revealing a black colour. It is thus possible to distinguish between older and younger beetles, as older beetles will have fewer hairs and thus be darker in colour. Females tend to lose more hairs, especially... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Shenandoah National Park | 🇺🇸 United States |
More parks will be added in future updates.
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Montreal | 🇨🇦 Canada | |
| 2 | Washington | 🇺🇸 United States | |
| 3 | Houston | 🇺🇸 United States |
With luck
About 10% of wildlife watchers report an American Rose Chafer sighting in Shenandoah National Park on a given day, based on 12 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 325th most-seen of the 723 insects we can rate there. Over three days the chance rises to about 20%, and over a week to about 40%, if each day is a fresh chance.
May and July
In those months about 10% of wildlife watchers report an American Rose Chafer in Shenandoah National Park on a given day, against under 5% in June and August–April, the lowest months.
Between 1 and 4 pm
Across all the parks we cover, that three-hour window holds the most American Rose Chafer sightings with a recorded time, and about 9 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
Only Shenandoah National Park, in our data
Shenandoah National Park is the only park on Wallace's Line with enough records to rate American Rose Chafer sightings: about 10% of wildlife watchers there report one on a given day.
Same family: Scarabaeidae
The closest relatives of the American Rose Chafer that you can see in Shenandoah National Park (family Scarabaeidae, Scarabs) are Common Green June Beetle (about 20%), Japanese Beetle (about 20%) and Eastern Hercules Beetle (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the American Rose Chafer is recorded against all the insects logged in Shenandoah National Park (12 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.
