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Female Sumac Gall Aphids Leaving Galls To Colonize Moss

The sac-like galls, often referred to as “Red Pouch Galls,” found on Staghorn and Smooth Sumac are anywhere from marble to ping pong ball-size, and usually become obvious in late summer and early fall when they often acquire a rosy pink blush. Inside the thin walls of these galls is one big hollow cavity, teeming with tiny orange woolly aphids (Melaphis rhois) referred to as Sumac Gall Aphids.

In the spring, female aphids lay an egg on the underside of a sumac leaf, causing the plant to form an abnormal growth, or gall, around the egg.   The egg hatches and the aphid reproduces asexually within the gall. Thus, all the aphids inside the gall are identical clones of one another. In late summer or early fall, the winged females fly to patches of moss, where they establish asexually reproducing colonies. At some point these clonal colonies produce males and females which mate and it’s these mated females that fly off to lay eggs on sumac leaves in the spring.

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8 responses

  1. Nature is so complicated!!

    September 30, 2022 at 8:31 am

  2. Karen Burns

    Their reproductive routine is rather complex!


    September 30, 2022 at 9:05 am

  3. Alice

    Mary: you sure know how to find everything in nature! Lovely colors.

    September 30, 2022 at 9:35 am

  4. Mary, this is fascinating. Any observations on the species of moss?
    Any chance the yellow donate button might reappear?

    September 30, 2022 at 10:23 am

    • Hi Micki,
      I wish I knew the species of moss, but I don’t! I didn’t know the donate button wasn’t there…but haven’t received any donations in quite a while. Will see if I can do something about that – thank you for alerting me!

      October 1, 2022 at 12:34 pm

      • You are welcome. The easier it is to donate, the more will do it.
        Love your work and hope all is well over there in the West.

        October 1, 2022 at 12:58 pm

  5. Our downy woodpeckers have been feasting on these galls for weeks. Lots of galls this year.

    September 30, 2022 at 7:58 pm

    • Fascinating, Eliza. I haven’t observed woodpeckers at them, but have seen holes made by some kind of predator!

      October 1, 2022 at 12:33 pm

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