22 May 2013
– Phyllis Montelese
What do Fluvanna Master Gardeners and cicadas have in common? They were both at Fluvanna’s Farmers Market at Pleasant Grove Tuesday. A red-eyed, clear-winged adult periodical cicada was discovered inside the Master Gardeners’ tent where they were set up to answer gardening questions. A small crowd gathered to see the docile stingerless cicada being gently handled by a Master Gardener. It was the first live adult cicada most had seen this year although some spoke of seeing several cicada “shells” (exoskeletons) around. Central Virginia is expecting an onslaught of these 13- and 17-year periodical cicadas this month with their numbers peaking in early June and gone by July.
The immature cicada nymph develops underground and feeds on sap from plant roots. After 13 or 17 years, the nymphs come out of the ground, climb onto nearby vegetation or any vertical surfaces, shed their exoskeletons, emerge as winged adults, and live for two to four weeks. Most annoying is the constant and loud singing of thousands of males as they woo females. Females lay their eggs inside small twigs by slicing into the wood. As the nymphs hatch, they fall to the ground, burrow underground and the cycle begins again.
Should we be worried about these periodical cicadas in the garden? Yes, if you have young trees, especially newly planted fruit and ornamental trees such as apple and dogwood. Tree branches split and die after the female cicada lays her eggs. You can spot what is called “flagging” when you look up into trees and see dead split twigs among healthy green foliage. While mature, larger trees (they like oak) can usually tolerate flagging, severe damage can occur in young and small trees because they are not as hardy with most of their small pencil-like branches as perfect candidates for egg laying.
What can we do to prevent damage? Wrap fine netting around the trunks of newly planted trees to stop the cicadas from climbing up the tree in the first place. This works because they don’t fly onto trees – they climb up from the ground. Be sure to remove the netting when the cicadas are gone. To reduce the cicada population the next time, every couple of days check your trees, promptly remove flagging damage that you can safely reach, and destroy the egg-laden clippings.
Go to the Virginia Cooperative Extension website http://pubs.ext.vt.edu/ and search publications and educational resources for more information. Check out the Fluvanna Master Gardeners website http://www.fluvannamg.org/ for more gardening tips and events in the area.