Fall is a great time of year to take a look at leaves, and the freaky ways in which insects can modify plants into houses for their larvae, producing a huge variety of freaky growths called galls.
The majority of insects that produce these structures are tiny gnats or wasps. The plant tissue responds to their invasion by producing extra tissue in a sort of decorative tumor. These little structures then become both protection and food source for the developing larvae–the ultimate bug condo.
The really fascinating thing about galls? The same plant will respond to different species of insects in different ways. That produces galls that are distinctive enough to be characteristic of individual species of insects.
Here’s an assortment of beautiful galls–click the photos to see the originals.
Why are they called Galls? Entomological lore has it that because woody plants are most commonly attacked by gall-making insects, these structures often have lots of tannins in them. Which would make them taste bitter–hence, Gall. Oak galls were often collected and used for tanning animal skins in Europe, as well as a source of dyes and inks.
A challenge for my more taxonomically advanced readers–can you name these gall makers?