Monday, April 23, 2012

Week Eight: Invasives and entomology

Dr. Ray Buchanan holds up Invaders of Texas: Volunteer Handbook, used as part of a citizen science program to detect and report invasive species in Texas.

Every Thursday, my 19 fellow classmates and I travel to unique and special sites in Central Texas, like Westcave Preserve and Inks Lake State Park. For our naturalist training, I’ve driven as far as 80 miles to Doeskin Ranch in Travis County.

Not this week. Lucky me–I had just a mile commute to the Blanco United Methodist Church for classroom instruction. The day also included a hike and lunch at Blanco State Park.

Week eight of our Texas Master Naturalist training with the Highland Lakes chapter covered invasive plants and entomology.

Dr. Ray Buchanan, a past president and Highland Lakes chapter member, presented our first class on invasives, which was held in the church’s fellowship hall.

“What are the various ways we identify plants?” he began. “By scientific name. What they are when they mature–shrub, tree, vine. How long they live–perennial or annual. We identify them by their leaves–deciduous or evergreen. We group them by vegetative zones. Are they deer resistant? Do they attract hummingbirds or butterflies?”

“But invasive…what does that term exactly mean?” Buchanan asked. His question got us to thinking.

Various Texas gardening and field-guide books published from 1987 up to 2006 don’t directly address invasives, he continued, holding up some examples. “So they don’t give us a lot of help,” he said. “Are corn, oat and tomato plants invasives?”


If a plant’s invasive, that seems to imply that it’s bad in some way. “The seeds of mountain laurels are toxic. Does that make the mountain laurel invasive?”


According to Buchanan, the definition of an invasive means that the species:

·      Does economic harm (destroys crops)
·      Harms the environment (destroys wildlife habitat and creates monocultures)
·      Harms human health and productive land management

“But how do invasives do all that–that’s my question,” Buchanan said. “They’re fast growing and fast spreading. They have if, if any, insect predators or diseases. So they survive, and they survive well. They smother new shoots of native plants and may exude toxic ‘allelopathic’ chemicals that can harm livestock or humans. Their structure helps them survive and thrive. They spread by seeds, runners and rhizomes. They may have extended growing seasons and climb on other plants.

“The key to a healthy ecosystem is biodiversity,” Buchanan said. “Our native plants have adapted to our soils and climate. We need our natives for biodiversity.”

What can we do as Master Naturalists?

“First, we must recognize that there’s a problem,” Buchanan said. “Secondly, because invasives don’t have boundaries, we must talk to our neighbors and our community. We’ve got to start at our borderlands and work inwardly. We must be persistent in the fight and focus on our own properties.”

After Buchanan finished his presentation, he talked about specific invasive species that threaten the Texas Hill Country.  

Janis examines a chinaberry branch.

Connie, a Master Naturalist with our Highland Lakes chapter, showed us a Johnson grass stem. The huge white stripe down the stem characterizes Johnson grass.  

Connie shows Ed some nandina foliage.
 After Buchanan’s presentation, we drove to Blanco State Park, where we met at the head of the Ira Caswell Nature Trail. Our mission on our 3/4-mile loop hike: find red yarn tags on invasive plant species that inhabit the park. 

We split into four teams and headed out. Judy, Joy, Ed and Kevin found our first: wax-leaf ligustrum.

M.J. kept track of our finds.

Judy and Ed found another species: Japanese honeysuckle.

Ed found the chinaberry tree.

Judy examined the chinaberry while M.J. noted the find.

The hike along the Ira Caswell Nature trail parallels the Blanco River part of the way.

After our hike, we enjoy picnic lunches at the Big Table (built by the Civilian Conservation Corps in the 1930s) that overlook the river.

After lunch, Kim Bacon–also a member of our Highland Lakes chapter–spoke on entomology, which is the study of insects. “As a Master Naturalist, you need to be curious and look into things,” she started. “Ask what’s that and what’s it doing?”

During her hour-long presentation, she next gave a brief overview of taxonomy, basic insect anatomy, and metamorphosis (complete versus incomplete).

"Being a naturalist is about getting OUT THERE," Bacon said. "Get a bucket, turn it upside down, sit on it, and watch a bug. You'll learn more about that bug than someone just sitting in a classroom, reading a book."

Bacon showed us the tools she uses in the field, like a camera, magnifying glasses, collection containers and this device, which sucks up insect specimens like a vacuum cleaner.

More than 40 years later, she still uses a press she made as a kid for preserving plant specimens.

Tom examines a beetle collection pinned and documented by Bacon.

[After class, Bacon told me that she recognized me…because she runs the Texas Bee Watchers website, and in February 2011, she bee-certified our Wildscape (#12). Among the photos of our Wildscape was one of me, which is how she recognized me. (Great memory, Kim!)]

 Master Naturalist Billy Hutson smiles for the camera with his beekeeper's suit. 

After Bacon talked, Master Naturalist Billy Hutson spoke on beekeeping, a hobby he got into back in the 1970s. "Bees are not native, but they fill a niche," he told us.

In a nutshell, we learned that: Queen bees live solely on royal jelly, produced by worker bees. Her only job is to lay 2,000 or so eggs a day. "So that's all she does: eat, poop and lay eggs," Hutson said. As a whole, a bee colony, which consists of a queen, many workers and a few drones (males), operates as one super organism. Anywhere from two to seven years of age, a queen bee gives off certain pheromones that tell workers that she's nearing death so they must nurture new queen bees. Out of five to 10 new queens, one will emerge first and then destroy the other queens. She will serve as the colony’s new queen until her life ends. 

Hutson passed around frames from his bee hives, which intrigued Janis and Kay.

After finishing his talk, Hutson sliced up bite-sized pieces of cornbread and topped them with his honey so we could taste it. Hmm, delicious!


Our class curriculum takes us to Pedernales Falls State Park, where we'll have a session on bird watching at the park's bird blind. We'll also learn about the birds and herps that live in the Texas Hill Country. 

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