Elm Seed Bug vs Australian Harlequin Bug

Side-by-side species comparison

Attribute Elm Seed Bug Australian Harlequin Bug
Scientific Name Arocatus melanocephalus Dindymus versicolor
Order Hemiptera Hemiptera
Family Lygaeidae Pyrrhocoridae
Size 6-7 mm 10-14 mm
Habitat Underground Underground
Diet Seed Feeders Predators
Regions Europe (native), Northwestern North America (invasive) Australia, Oceania
Conservation Least Concern Least Concern

Elm Seed Bug

A small seed bug native to southern Europe that has become an invasive nuisance pest in the northwestern United States. It aggregates in enormous numbers on and inside buildings in summer and fall.

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Did You Know?

Thousands can invade a single home seeking shelter, producing a foul odor when disturbed or crushed.

Australian Harlequin Bug

A small but conspicuous red and black bug that often aggregates in large numbers on tree trunks, fences, and walls during autumn. Its bright colouration warns predators of its foul-tasting defensive secretions.

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Did You Know?

Harlequin bugs produce a pungent smell when disturbed, and large aggregations can number in the thousands.