She’s less than a centimeter long, produces only daughters and is conquering the continent without a single male. Meet the elm zigzag sawfly, named for the delicate zigzag patterns it carves into elm tree leaves.
Despite its name, the elm zigzag sawfly (Aproceros leucopoda) is not a fly; it is a type of wasp first discovered in North America in 2020. Originally from East Asia, it has expanded its range at an “alarming” rate, researchers report in the Journal of Integrated Pest Management. For cities still recovering from elm canopies lost to a fungal disease, it’s an unwelcome second wave of assault. And newly emerging evidence suggests it won’t