So-named because its gnarled trunk can split as it grows, the crack willow can be seen along riverbanks, around lakes and in wet woodlands. Like other willows, it produces catkins in spring.

With black-and-yellow markings, the hornet robberfly looks like its namesake, but is harmless to us. This mimicry helps to protect it from predators while it perches in the open, waiting for its…

Living up to its name, the cherry gall wasp produces growths, or 'galls', on oak leaves that look like red cherries. Inside the gall the larvae of the wasp feed on the host tissues but…