Journal archives for June 2019

18 June, 2019

Leafcutter ants: An ally against glossy privet

I have known for some time that leafcutter ants will attack glossy privet. I had even noticed that they seem to do so preferentially. In Austin's Walnut Creek Metropolitan Park, a couple of large colonies seem to be eating nothing else.

I had not realized that leafcutter ants could kill ligustrums. They certainly strip the leaves, but they don't seem to be able to keep up with the plant's growth.

All around this huge leafcutter ant mound we can find dead ligustrums. Volunteers working with me have girdled many in the area—but not these. We meant to get to these glossy privets eventually, but the leafcutters beat us to it.

Perhaps if left to their own devices these ants would never have killed the ligustrums. Perhaps it is that we removed so many seedlings, saplings, and mature trees that the ants overwhelmed whatever remained behind. But they also seem not to have cultivated a taste for other plants in the area.

If only I could convince them to try Chinese pistache, chinaberry, and giant reed…

Posted on 18 June, 2019 02:48 by baldeagle baldeagle | 1 observation | 2 comments | Leave a comment

Diary of the Glossy Privet's Grim Reaper

Several years ago, I took on the task of eradicating Ligustrum lucidum, also called glossy privet, and other invasive plants rom Austin's Walnut Creek Metropolitan Park. The idea that we could eradicate them is ambitiously optimistic, but I have a feeling we will do far better than just to manage them. Besides, with that goal in mind, I am inspired to keep trying new twists on my techniques for reducing their numbers.

In this series of posts, I plan to share my observations of the impact of glossy privet on the plant communities in this park and the results—successful and otherwise—of our attempts to bring them under control. Follow me and you will find facts worth discussing, with details to back them up:

  • Glossy privet is so beautiful every spring, and it's a bulletproof evergreen. What makes it the most perniciously invasive woody plant in Central Texas?
  • Not all tree extractors are alike—and it isn't just the trade name that makes the difference. When you put them in the hands of volunteers, which ones work best? Why?
  • How does girdling work? If you have tried and failed, I can show you the way to succeed—and it's probably easier than whatever you've done before.
  • Nature abhors a vacuum. If we can get rid of the ligustrum, what will we put in its place?
  • What other invasive plants are making inroads in the park—and how can we show them the way out?

One thing you won't hear me discuss is herbicide. At least three friends of mine have died from cancers linked to herbicides. It's better for us and our planet if we don't use them. And even if that weren't my position, I would still have to figure out how to get the job done without them. In Austin's parks, greenbelts, and preserves, volunteers are not allowed to use power tools or herbicides.

As a teaser, the photo associated with this post shows 55 glossy privets uprooted in 90 minutes by one of my volunteers last weekend. In the background, you can see larger glossy privets that we girdled in the same project. In my posts, I'll follow this and other areas as the ligustrums decline and the new habitat emerges.

And your comments will always be welcome.

Posted on 18 June, 2019 03:39 by baldeagle baldeagle | 1 observation | 5 comments | Leave a comment

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