Maladera formosae
In 3 days ~10% in a week ~30%
Maladera formosae, commonly known as the Asiatic garden beetle and formerly known as Maladera castanea, is a species of beetle in the family Scarabaeidae. It is native to Japan, China, Taiwan, South Korea, North Korea, and Russia but was introduced to North America in the 1920s where it is considered a pest of turfs, gardens, and crop fields. Adults are active in the summer during which they can be found feeding on leaves and flowers or gathering around light sources at night.
Adults range in length from 8-9mm and are reddish-brown in color with an iridescent sheen. Larvae, similarly to larvae of other species in the family Scarabaeidae, are referred to as white grubs. M. formosae grubs grow from approximately 1.4 mm to 19 mm in length as they feed on plant roots and decaying plant material.
Maladera formosae are frequently mistaken for other species of scarab beetles. However, adults can be distinguished by their sturdy bodies, reddish-brown hue with an iridescent shine, concealed labrum, antenna with 10 segments, flat rear tibia featuring apical spurs separated by tarsal articulations, and elongated male genitalia with sizable, movable apical hooks.
Larvae have C... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|
More parks will be added in future updates.
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Montreal | 🇨🇦 Canada | |
| 2 | Boston | 🇺🇸 United States | |
| 3 | New York City | 🇺🇸 United States | |
| 4 | Baltimore | 🇺🇸 United States | |
| 5 | Philadelphia | 🇺🇸 United States | |
| 6 | Washington | 🇺🇸 United States | |
| 7 | Minneapolis [Saint Paul] | 🇺🇸 United States | |
| 8 | Chicago | 🇺🇸 United States |
With luck
About 10% of wildlife watchers report an Asiatic Garden Beetle sighting in Montreal on a given day, based on 66 verified sightings from GBIF citizen-science data. It is the 155th most-seen of the 926 insects we can rate there. Over three days the chance rises to about 10%, and over a week to about 30%, if each day is a fresh chance.
July and August
In those months about 10% of wildlife watchers report an Asiatic Garden Beetle in Montreal on a given day, against under 5% in September to June, the lowest months.
Yes
Of the 8 cities where we can rate Asiatic Garden Beetle sightings, Montreal has the highest daily chance: about 10%. Next come Boston (United States, under 5%) and New York City (United States, under 5%).
Same family: Scarabaeidae
The closest relatives of the Asiatic Garden Beetle that you can see in Montreal (family Scarabaeidae, Scarabs) are Japanese Beetle (about 30%), Grapevine Beetle (about 10%) and Hermit Flower Beetle (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Asiatic Garden Beetle is recorded against all the insects logged in Montreal (66 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.
