Species Heterarthrus nemoratus - Late Birch Leaf Edgeminer

Birch Leaf Edge Miner(1)

Heterarthrus nemoratus (Fallén 1808)

4.5 mm(1)

native to Europe & w. Siberia, adventive in NA (across the north)(3)(1)(4)

host: Betula (Birch)(2)

Parthenogenic; the only birch leafmining sawfly to pupate in the leaf

One generation per year. Overwinters as larvae. Eggs deposited in slits cut in the edges of mature leaves at all levels in the trees. Larvae produce large, blister-like or blotch mines free of frass. Mature larva builds a cocoon or hibernaculum within its mine. The leaf then falls to the ground and the larva stays there throughout the winter.(5)

Introduced from Europe early in the 20th century(3); at one time a severe pest of wild birch, now a minor aesthetic pest(1)

In the 1920s/1930s several biocontrol agents were imported, Kratochviliana laricinellae and Phanomeris phyllotomae became established