Megacopta cribraria
In 3 days ~20% in a week ~40%
Megacopta cribraria, also called the bean plataspid, kudzu bug, globular stink bug and lablab bug, is a shield bug native to India and China, where it is an agricultural pest of lablab beans and other legumes. The bug, while harmless to houseplants and people, often enters houses. It is attracted to white surfaces such as the walls of houses or white vehicles, because of the high reflectance of the white surfaces as it relates to the bugs' simple eyes. As a defense mechanism, they emit a foul-smelling pheromone that also acts as a congregation pheromone. Aside from smelling foul, the liquid also creates a burning sensation and sometimes leaves a red welt on bare skin. It is similar to other Plataspidae in having a somewhat unusual symbiotic relationship with its gut bacteria. Before laying eggs, females deposit particles containing the symbiont, which are then eaten by newly hatched nymphs under natural conditions. Nymphs experimentally deprived of access to the symbiont exhibited slower growth, smaller body sizes and higher mortality.
Megacopta punctatissima, the Japanese common stinkbug, is a name applied to Japanese populations of M. cribraria. It has a gut bacteria that allows it to consume crops such as soybean plants. The two used to be treated as distinct species, but phylogenetic work has found the two to be not distinct. What is called M. cribraria in the United States likely descends from a population of "M. punctatissima" from Kyushu, Japan. The Japanese (JA) population is closest to the East Asian continental (EAC) population. The two diverged 0.71 Mya (million years ago), when the East China Sea land bridge became submerged. The EAC population branched off from the Southeast Asian (SEA) population 1.34 Mya.
The bean plataspid gives off an offensive odor when touched, squashed, or poked. Hosted by wisteria, green beans, and other legumes, the insect sucks juice from the stems of soybean plants and reduces crop yield. However, when the insect infests kudzu, another invasive species, it appreciably reduces the growth of that plant. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Great Smoky Mountains National Park | 🇺🇸 United States |
More parks will be added in future updates.
With luck
About 10% of wildlife watchers report a Kudzu Bug sighting in Washington on a given day, based on 338 verified sightings from GBIF citizen-science data. It is the 154th most-seen of the 1807 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.
April, July–August and October–December
In those months about 10% of wildlife watchers report a Kudzu Bug in Washington on a given day, against under 5% in January–March, May–June and September, the lowest months.
Between 3 and 6 pm
Across all the parks we cover, that three-hour window holds the most Kudzu Bug sightings with a recorded time, and about 9 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
Among the best
Of the 8 cities where we can rate Kudzu Bug sightings, Washington ranks 3rd at about 10%, level with the leaders once rounded. The best odds are in Naha (Japan, about 10%) and Tuen Mun (China, about 10%).
Same order: Hemiptera
The closest relatives of the Kudzu Bug that you can see in Washington (order Hemiptera, True Bugs, Hoppers, Aphids, and allies) are Spotted Lanternfly (about 40%), Large Milkweed Bug (about 20%) and Brown Marmorated Stink Bug (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Kudzu Bug is recorded against all the insects logged in Washington (338 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.
