Science Friday - Flagging

Recently, we noticed a number of dead branches in what are otherwise healthy trees in our yard, particularly the weeping willows. We correctly suspected cicada damage. The female uses her oviposter like a tiny saw, making two parallel lines that split the twig and there she deposits her eggs. This causes the twig to die and hang down, which is why it is referred to as "flagging".


The above photo shows the slits in the twig. Using a compound microscope, we were able to view the little rice-like eggs that were in the holes. We put the branch back outside so that after the eggs hatch, the nymphs can burrow down into the soil and grow for the next seventeen years. By the next time we see them, William will be twenty three years old and will, like the cicada nymphs, also have transformed into a different creature altogether.