Boisea rubrolineata
In 3 days ~60% in a week ~90%
Boisea rubrolineata or the western boxelder bug is identical to the eastern boxelder bug aside from having prominent red veins on its corium. It is found in western North America. Adults are 9–13 mm in length. The thorax and wings are black with red lines, and the abdomen is red. Nymphs are bright red and gray. Both nymphs and adults feed on boxelder. In fall and winter, adults might be noted migrating indoors to hibernate. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Yosemite National Park | 🇺🇸 United States | |
| 2 | Sequoia and Kings Canyon National Parks | 🇺🇸 United States |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Portland | 🇺🇸 United States | |
| 2 | Sacramento | 🇺🇸 United States | |
| 3 | San Francisco | 🇺🇸 United States | |
| 4 | Seattle | 🇺🇸 United States | |
| 5 | Los Angeles | 🇺🇸 United States | |
| 6 | San Diego | 🇺🇸 United States |
Possible
About 30% of wildlife watchers report a Western Boxelder Bug sighting in Portland on a given day, based on 786 verified sightings from GBIF citizen-science data. It is the 2nd most-seen of the 507 insects we can rate there. Over three days the chance rises to about 60%, and over a week to about 90%, if each day is a fresh chance.
March–July and October–November
In those months about 30% of wildlife watchers report a Western Boxelder Bug in Portland on a given day, against about 10% in September and December, the lowest months.
Between 2 and 5 pm
Across all the parks we cover, that three-hour window holds the most Western Boxelder 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.
Yes
Of the 6 cities where we can rate Western Boxelder Bug sightings, Portland has the highest daily chance: about 30%. Next come Sacramento (United States, about 20%) and San Francisco (United States, about 10%).
Same order: Hemiptera
The closest relatives of the Western Boxelder Bug that you can see in Portland (order Hemiptera, True Bugs, Hoppers, Aphids, and allies) are Western Conifer Seed Bug (about 20%), Brown Marmorated Stink Bug (about 20%) and Leafhopper Assassin Bug (about 20%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Western Boxelder Bug is recorded against all the insects logged in Portland (786 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.
