June 2013 in our Wildscape

A chapter closes

Today a chapter in my mother's family closes. Actually, it's more like a book. Today, the San Marcos home that her parents had built in 1938 and where she and her two brothers grew up will change owners. This special place has been in our family for nearly 75 years. Today, someone else will begin a new chapter within its rooms and hallways. 

As a little girl myself, I spent many a summer day there, sitting in the grass beneath the sycamore trees. Balancing on the metal bars where visitors once tied their horses. Imitating the call of mourning doves perched among the pecan leaves. Playing a board game with my sweet (and patient) Uncle Jim. Digging through my fancy play purse, a hand-me-down filled with goodies by my grandmother, Debbie. Eating vanilla ice cream (topped with cherry juice) with Daddy D, my grandfather. "Tastes like more, eh?" he'd grin at me. Oh, yes!

That's life. A series of endings. And beginnings. I wish much happiness to the new owner. I really do! And I hope to nurture a little piece of my family's San Marcos home in our own yard...a small yet unidentified plant that was growing like a weed near the street. I'm guessing it's a species in the mint family, but I'm not sure yet.   

Get that grass!

For a long while, I'd been eyeing this colony of invasive Johnsongrass (Sorghum halepense) that's growing in a field across the street. According to the Texas Invasives database, "Johnsongrass is considered one of the 10 most noxious weeds in the world." So while I was over there in the field, photographing invasive nandina, I pulled on my green gloves and then pulled out that nasty bunch of Johnsongrass. It's gone now.  

Last spring, I learned in my Texas Master Naturalist classes to look for a tell-tale marking. Johnsongrass always has a distinctive white line up the leaf.

The species, which was brought to the States as a forage crop in the early 1800s from the Mediterranean region, has vigorous rhizomes. And that's no lie! Just look at this one!

I didn't pull up all the Johnsongrass. There's more. And only one of me. Plus, I decided that maybe I'd better ask the owner first.....

Tricked...or not?

A native flameleaf sumac? Or...HORRORS...a nandina?

Last fall, James spotted what he thought might be a flameleaf sumac growing at the edge of our front cement porch. So he dug it up, and I've been nurturing the mystery sapling in a plastic pot. Here lately, I've been suspecting that maybe it's a poser. As in...an invasive nandina (Nandina domestica). Major YUCK. They grow in the neighborhood, both invited and as a volunteer. I walked across the street this evening and took some leaf close-ups on a volunteer nandina that's growing in a field. 

I've pulled up leaf images of both plants and am still scratching my head. But I'm back to thinking that I'm tending a flameleaf sumac. I SURE HOPE SO! But then I look at more leaf images and conclude NAW, IT'S NANDINA!

Guess I'll think about this dilemma another day....

Nandina branch

Sick frits

Melt and Wilt. 

Zombie disease. 

Black Death. 

NPV, short for Nulcear Polyhedrosis Virus.

I've found a number of different names for what's sickening some of our Gulf fritillary caterpillars on a passionflower vine. Yes, they're dying again. I first reported on this phenomenon three summers ago ("I feel like a murderer," June 14, 2010) and again last year ("More caterpillar deaths..." March 30,2012). It's very frustrating. In 2010, I cut down the passionflower vine on which the affected cats were dying. That seemed to help. But I still see caterpillars sickening, blackening and dying. 

Last year, I also saw other caterpillar species dying to I posted a photo at Bugguide.net. That's "possibly a baculovirus, which causes caterpillars to liquefy and eventually splash new virus particles onto the leaf, which may then be consumed by more caterpillars," replied Ian Stocks. He pointed me to a 2003 academic article in the Journal of Invertebrate Pathology: "A newly discovered baculovirus induces reflex bleeding in Heliconius himera."

So what IS a baculovirus? Google the word, and Wikipedia's definition will make you yawn...The baculoviruses are a family of large rod-shaped viruses that can be divided into two genera..." (Wikipedia even has a disclaimer: "This section may be too technical for most readers to understand." AMEN!) 

Here's the rest of Wikipedia's definition: Baculoviruses have very species-specific tropisms among the invertebrates with over 600 host species having been described. Immature (larval) forms of moth species are the most common hosts, but these viruses have also been found infecting sawflies, mosquitoes, and shrimp. Although baculoviruses are capable of entering mammalian cells in culture they are not known to be capable of replication in mammalian or other vertebrate animal cells. Baculoviruses contain circular double-stranded genome ranging from 80–180 kbp."

Now THAT explanation sure helps understand what's afflicting our caterpillars....

From what I can gather (from sources like NPR, NewScientist and National Geographic), "the government" sprays a baculovirus on trees to control gypsy moth outbreaks. However, researchers involved in the project reported on in 2011 by the aforementioned sources were more interested in how the baculovirus affects caterpillar behavior.

Personally, I want to know if this so-called pathogen is spreading to other caterpillar species, namely our Gulf fritillary cats!    

I've emailed Dr. Kelli Hoover at Penn State's Entomology Department (who conducted the 2011 research) but as yet have not received a reply. I also messaged a researcher associated with the 2003 research on baculoviruses and Heliconius himera (Gulf fritillary) caterpillars. Dr. Boucias wrote me right back and asked that I send him a sample caterpillar! 

"I would agree that the images look like the insects are infected with a baculovirus," he told me. "I should be able to readily confirm if this in fact is the cause."

Stay tuned!

Time for bees

A lot of folks, if they saw me wandering through our yard as much as I do, might say I have way too much time on my hands. As for me, I say I don't have ENOUGH! Because sometimes, waiting for nature to unfold requires a LOT of time...and patience. Take yesterday afternoon, for instance. I happened to be in the back yard with my camera, looking at plants, when I saw a bee dart into a hole. If you're the size of a bee, then this hole might be cave size. From this perspective, her hole looked like a cavern entrance on the side of a hill.

 See the hole? In the photo above, it's on the far right side, middle of the image. So I decided I'd wait and see if I could catch a picture of her. While I crouched on my haunches, I took some pictures of the...

...volunteer vine, likely in the morning glory family...

...the volunteer black-eyed susan, likely planted by a bird...

...and the healthy prairie verbena (I think that's right).

Meanwhile, I heard and barely saw a bee circle me at least twice. Then she landed on the dirt mound just out a bit from my elbow. "C'mon, you lost?" I said, "don't you know where your nest is?" Finally, I stood up to take a break, and she made a bee-line for a different hole! She'd been politely waiting for ME to move out of her way. In the photo above, her hole is just beneath the little white pebble. She's likely a different bee mom.

Here's another shot of her nest entrance. Alas, some rain started so I headed for the house. No more waiting on bee appearances the rest of the day.

 

This morning, I got a shot of her entrance. But no bee mom. (Yesterday heavy rains really brightened up our small crop of moss!)

Just awhile ago, I went back out with my camera and got a few shots of her working on her nest. I've seen her abdomen and her green eyes so I'm pretty sure she's a digger bee species of Anthophora. Nearly three years ago, I blogged about the same species–"Acrobatic bee!"–when I found one roosting in our globe mallow. They're cool.

Time permitting, I'll keep trying to get a better photo of her. Wish me luck!

Passionflowers

Passionflower blooms are just gorgeous. I was out photographing sick Gulf fritillary caterpillars (separate post) when I had to stop and snap some flower pics. The bees love passionflowers, too.

Yesterday, I finally planted two yellow passionflowers (Passiflora lutea) that I potted up from the adjoining neighbor's yard. Here's hoping they take!