Galls that form on plants often stick out and draw our attention. For Red Bay, the bright green galls stand out against the dark green leaves and are part of a natural relationship between a tiny insect and its host plant. Rarely seen, the galls are the only obvious evidence that these insects exist. Here is their story.
Red bay is a common small tree found throughout the coastal region of the Gulf and Atlantic coasts. Its leaves are our native version of the bay leaves that are usually purchased in stores and used in many recipes. A quick sniff of a crushed leaf is all you need to confirm. But there is rarely one of these plants that doesn’t sport a few, if not numerous, odd-shaped galls that form along leaf edges.
These galls are the home of the Red Bay Psyllid, Trioza magnoliae. These rarely seen insects belong to the Order Hemiptera or True Bugs, that include more commonly known insects like stink bugs and cicadas. In fact, adult Red Bay Psyllid, when you can find one, looks much like a tiny cicada. Their close relatives include plant lice that can cause issues on ornamental plants.
But Red Bay Psyllids do little real harm to Red Bay, that is a robust and hardy species. The galls appear after young nymphs begin to feed, causing the edges of leaves to curl over, creating a hollow pocket gall, that can hold multiple nymphs. Young nymphs are yellow and slow-moving insects that feed from within the gall, sucking plant juices. Older nymphs are larger and green with orange wing pads. Adults have elongated clear wings and resemble cicadas.
To see one of these creatures is to carefully open a green gall and view the nymphs with a magnifying lens. They are quite small. From what is known of this insect, multiple generations are possible each year. A flush of new galls comes in early spring, with additional new galls later in summer. By winter, the galls die on the evergreen leaves of the plant, appearing as shriveled and brown or black.
Many of the creatures in our world live out of our sight or knowledge. For Red Bay Psyllids, they are hidden from our direct view but are quite common. So too is at least one tiny parasitic wasp that attack these insects.
But as I share what I know about these cool creatures to folks on nature tours, they are just part of the natural world around us. Nothing really bad about them, as this plant and insect relationship is likely very old. As for using Red Bay leaves in your recipes, don’t worry about having a small gall or two on the leaves you put in your pot. The added protein can’t hurt.
Hope to see you in our great outdoors!