View All Aug 2, 2016

Found on the Greenway: Sumac

By: Jim Bogenschneider, Catawba Master Naturalist

Sumac is a very common plant on the Greenway and is considered to be a shrub or a small tree. There are about thirty five species of Sumac, with the winged and smooth being the most common and the stage horn being less common in our area. To the south of us, in the sand hills, you will find the poison sumac. In this article I would like to explore the smooth sumac and a very unusual relationship it has with an aphid.

JimB_Pic1_SumacAphid.jpg JimB_Pic2_SumacGall.jpg

                         Melaphis rhois                                                              Sumac Gall

The Rhois aphid is the only species in the genus Melaphis. When female aphids lay a single egg on the underside of the sumac leaf this forces the sumac to form a sac over the egg forming a gall. In late summer female aphids leave the gall and seek out a certain moss to continue their life cycle. This use of the moss as a food source produces males and females that will return to the sumac and start the cycle over again. In 1989 paleo botanical evidence suggested that this aphid has been associating with this sumac host plant since the early Eocene, 48 million years ago. I have only found the smooth sumac at two locations on the Greenway, one at Lake Crandall just to the right of the pier and the other on the north shore of Lake Haigler. I have been observing these aphids for a couple of years now and haven't found the moss that they feed on yet, but I will continue to look. The closer I get to nature the more amazed I become, to think that an animal and a plant can be so intricately involved for 48 million years is astounding. As always I can’t wait to see what else nature is up to and what can be found on the Greenway.

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