box elders，梣叶槭‌，也常被称为梣叶枫、复叶槭，是无患子科槭属的落叶乔木，本质上属于一种特殊的枫树。
This fungal disease, dubbed fusarium dieback, triggers drought-like symptoms which lead to severe damage and, often, death. How long the tree survives upon infestation can depend on the species, explains Roets; oak trees typically die within four years, while box elders often don’t survive beyond the first 12 months.
Just a single beetle can start an epidemic. Unusually for insects, the polyphagous shot-hole borer does not require a male to produce offspring. A virgin female can lay unfertilized eggs which develop into males that she can subsequently mate with to start new colonies, a system known as haplodiploidy（单倍二倍性，一种性别决定系统，未受精卵→单倍体雄性；受精卵→二倍体雌性）.