Elm Seed Bug

Pest Description

• adults: 1/3 inch; alternating black and red pattern outside of wings; red underside (abdomen)
• triangular segment behind head is black and surrounded by red on the top portion of the wings
• nymphs: smaller; red abdomens and black wing pads and head

Host Plants, Diet & Damage

• elm; linden
• feed primarily on sap from elm seeds and leaves
• no damage done to tree
• congregate on structures and can come indoors during hot periods of the summer
• overwinter in cracks, crevices, leaf litter and in buildings
• may stain lightly colored materials with fecal material
• emit an unpleasant odor when bothered

Biology, Life Cycle & Damaging Life Stage

• overwinter as adults in and around homes
• become active in March with warming temperatures
• adults lay eggs on elm seeds and trees in May
• one generation per year, but overlapping life stages may be present

IPM Recommendations

• No damage to trees; nuisance pest only.
• Remove unwanted/volunteer 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.

For more information, see our Elm Seed Bug fact sheet.