Red-shouldered bug
This true bug is often mistaken for the boxelder bug it resembles, but it feeds mainly on golden rain tree seeds rather than boxelder seeds.
| Where | Gardens, woodlands and building walls |
|---|---|
| Size | 10 to 14 mm body length |
| When | January to December |
The red-shouldered bug is mostly black with bright red edging on the thorax and red eyes, and its dark wings carry a reddish tint but no red along their edges. This sets it apart from the similarly patterned boxelder bug, which shows more red striping and red edged wings.
Adults and nymphs gather in large groups on sun warmed walls, tree trunks and rocks, feeding mainly on the seeds of goldenrain trees and other soapberry family plants. In warm regions several generations can develop in a single year.
Traits
Habitat
Towns
Colour
Black, Red
Active
Day
To people
Gathers in large groups on walls and trees but does not bite or sting people; a nuisance only in numbers.
Activity through the year
Often confused with
Very similar in size and habit, but the Boxelder bug shows more extensive red striping on the thorax and red edges along the wings, rather than the mostly black body of the Red-shouldered bug.
Questions
Is the Red-shouldered bug dangerous to people?
Gathers in large groups on walls and trees but does not bite or sting people; a nuisance only in numbers.
When can you see the Red-shouldered bug?
The Red-shouldered bug can be seen from January to December, by day.
Plate retouched from a photo by Sam Kieschnick, CC BY 4.0, iNaturalist Licence
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True bugs›Scentless plant bugs›Jadera
Last updated 2026-09-27. Every entry is checked against published sources.