Elm Leafminer vs Birch Catkin Bug

Side-by-side species comparison

Attribute Elm Leafminer Birch Catkin Bug
Scientific Name Fenusa ulmi Kleidocerys resedae
Order Hymenoptera Hemiptera
Family Tenthredinidae Lygaeidae
Size 2.5-4 mm (adult) 4-5 mm
Habitat Woodlands Woodlands
Diet Herbivores Seed Feeders
Regions Europe, North America Europe, northern Asia, North America
Conservation Not Evaluated Least Concern

Elm Leafminer

A sawfly whose larvae mine between the upper and lower surfaces of elm leaves. Mines appear as blotchy brown patches on foliage.

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Did You Know?

Each larva creates a single blotch mine that can expand to cover half the leaf.

Birch Catkin Bug

A small, oval brown seed bug that feeds on birch and alder catkins. It is very common in northern Europe and can form large swarms in autumn. It sometimes enters buildings in large numbers seeking overwintering shelter.

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Did You Know?

In autumn, enormous swarms of thousands can descend on buildings near birch trees, alarming homeowners despite the bugs being completely harmless.