Hackberry "nipplegall" on the underside of a leaf. |
I know many people consider them ugly, especially given their prevalence on an infected tree... but I really like Hackberry Galls. This time of year, just before the adult insects emerge from the galls sometime in September, there are these tiny yellow insects inside. They're not really viable yet but they're big enough to walk around, and they're kind of cute. (Yes, I recognize that I've essentially killed the one pictured here to photograph it, but they seem like a pretty renewable resource, so to speak.)
These insects have a fascinating life cycle (similar to many gall-creating critters). When they come out in a month or so as adults, they will still be small, less than 1/4 inch long. They look like mini versions of their close relatives, cicadas and leaf hoppers. They will seek a relatively protected place to overwinter, such as inside cracks in bark, where they will hibernate. In the spring, they will awaken and lay their eggs on the underside of the new leaves of a hackberry tree. The baby bug causes the tree to start growing around it -- I believe because of an enzyme they secrete when they eat. The result is a gall, a growth made of plant material that houses the little insect. In this protected environment, the insects spend the summer sucking on sap until they are full grown and ready to come out and start this process over. The hackberry trees aren't harmed by the galls, other than in the aesthetic sense. (I don't think the trees actually care how they look).
I bit open the gall to study this fellow who was living inside! |
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