Elm Seed Bug
Arocatus melanocephalus
Identification
- black and red bug about 1/3 inch long
- triangular segment between the top part of the wings
- triangle is black and surrounded by red on the top portion of the wings (see bottom picture, 2nd bug)
- alternating black and red pattern outside of wings
- red abdomen on underside
Nesting Habits
- found in and around buildings in the spring and fall, especially outdoors where elm seeds have accumulated in the spring
- elm trees
Diet
- elm seeds
Significance
- nuisance: congregate around buildings that have nearby elm trees and elm seeds; can come indoors and annoy occupants
- overwinter in cracks and crevices in buildings
- may stain lightly colored materials and emit an unpleasant odor when smashed
- not a health threat
IPM Recommendations
- Remove elm trees in the area if possible.
- Seal cracks that may allow bugs to enter buildings.
- Vacuum to remove indoor and outdoor populations.
- Remove elm seeds that have collected around buildings.
- Remove elm from tree planting lists.
- Remove volunteer elm while they are small.
For more information, see our Elm Seed Bug fact sheet.