Tag Archives: Hemidactylus turcicus

Mornings at the Triffid Ranch

In most locales in the US, the Fourth of July holiday week involves chilled watermelon, grilled bratwurst, or trying to put significant portions of our landmass into low-Earth orbit. Around here, it’s best recognized by the visitors. Alarm clock goes off, stumble to the shower, get out, start to dress, and find this little guy in my pants pocket:

Baby gecko

For those not familiar with herpetology, this is a baby Mediterranean gecko, Hemidactylus turcicus. Earlier in spring, the females of the local H. turcicus population laid their eggs in protected spots in houses in the Dallas area, gluing the eggs onto the undersides of aluminum siding or the insides of bricks. Right about now, the hatchlings emerge, trying to stake out new territories, and that usually involves their climbing through doorways and cracks in windowframes. This little guy probably climbed down the bathroom vent pipe before dropping onto the carpet and hiding out in my pocket.

Baby gecko 2

And before anyone asks, he was promptly released after a couple of photos. Between normal dry conditions in North Texas this time of the year and the further dehydration from air conditioning, these geckos are best kept outside. It’s all for the best, really, seeing as how someone needs to help keep the mosquito and whitefly population under control, right?

“I Can’t Believe I Ate The Whole Thing.”

The weather has been strange in North Texas, but not as strange as it was last year. That said, we’ve had odd fluctuations in both temperature and humidity, with mixed results among the carnivores. The flytraps and butterworts love the available prey, and they can’t complain about surprisingly cool mornings. The Sarracenia, though, are having a few problems, and it’s because they’re a little too good at their jobs.

One of the last things a wasp ever sees

For the uninitiated, this is the throat of a North American pitcher plant hybrid, Sarracenia spp.. For a lot of insects, this is one of the last things they’ll ever see. The hood on top secretes nectar that attracts everything from gnats to wasps, and the throat of the pitcher produces even more. On good days, you can actually see wasps hanging on with their rearmost pair of legs, desperately trying to keep their balance and not fall in. If they do, well, they aren’t getting out. The nectar contains a drug called coniine, getting the bug drunk in small doses and becoming lethal in large ones, so that only improves the odds that they’ll slip.

Unlike the other plants worldwide that garner the name “pitcher plant”, Sarracenia are a bit more aggressive in retaining prey. Sarracenia shares with its distant cousins a wide throat area lined with wax, so dislodged insects that lose their grips slide inside. Like their cousins, the throat is shaped so that any bug that tries to fly out finds that it’s actually pulled deeper into the plant’s trap. (This isn’t completely true, as some insects and their larvae regularly feed on larger relations that can’t escape. However, we’re talking about the majority.) About a third of the way down, though, the inside of the pitcher is lined with sharp and strong downward-pointing hairs, and I can attest from bloody experience as to their strength and sharpness. (Let’s just say that cutting a damaged pitcher in half lengthwise and running your finger the wrong way up the pitcher interior isn’t exactly like running your finger up a bandsaw blade, but the effect is much the same.) Trapped bugs get a choice: fight the flow of the hairs and get punctured, or keep going down. Ultimately, the bugs run out of “down”, and that’s when the plant secretes digestive enzymes and breaks down the doomed critter. The plant absorbs needed nitrogen and phosphorus, and the vermin census in the immediate vicinity is down by one.

Sarracenia heartburn

As just about everyone who ever keeps Sarracenia is concerned, the plants are absolute pigs. In particularly lively periods for bugs, the pitchers can literally fill to the rim, with insects falling in and then crawling right out over the corpses of their brethren. In more insidious cases, though, one can see these strange burn spots on the pitcher sides, looking as if someone took a lighter to the trap. Beginners understandably panic about a blight or other disease and start spraying, but the real reason is a bit more insidious.

Let's take a look inside, shall we?

To find out more, you have to give whole new meaning to “peeking under the hood”. With a gentle touch, it’s possible to bend the hood back and take a look inside. (Afterwards, wash your hands, and make sure that you don’t put your fingers in your eyes or mouth before doing so. I’ve never had a problem with coniine toxicity, but that’s probably because I don’t take risks with the same active ingredient that makes hemlock-cooked hot dogs so tasty.)

Sarracenia interior

And here’s the problem. The previous few days saw two major factors that affected this Sarracenia: ridiculously dry days and ridiculously moth-filled nights. The relative humidity outdoors reached as low as 15 percent, meaning that the plant couldn’t produce its digestive fluids as quickly as it would have liked. Since Sarracenia don’t have teeth or other structures to increase the surface area exposed to enzymes, the trapped moths, and there are a lot of moths down there, started to rot before the plant could digest them. If the rot is bad enough, it burns the inside of the leaf, working its way out, leading to those scars on the outside of the trap.

Now, this can happen in different circumstances, usually involving extremely low temperatures or lack of sunlight. In this case, it was caused purely by low humidity combined with especially intense sun due to that lack of humidity. (The sun was intense enough to give some of my cactus sunburn, and it helped keep me inside until dark.) Either way, the affected pitchers themselves will die, ultimately, but the portions that didn’t burn will continue to take advantage of the nitrogen bounty and pass that to the rest of the plant. By September or October, this will be a very, very happy pitcher plant.

As an aside, when watching Sarracenia in the wild or in collections, keep an eye open for other interlopers. When I was first exposed to Sarracenia when living in Tallahassee a decade ago, I noted the number of green tree frogs that camped out in the pitchers. It’s a very handy relationship for both plant and frog. The frog has a place to hide from predators, and prey comes to it instead of the other way around. The plant effectively gets a set of teeth, as the frog snatches prey too large for the plant to digest effectively and then uses the pitcher as a toilet afterwards. The plant certainly isn’t complaining about getting its nitrogen pre-chewed, and if the frog dies of natural causes, then the plant gets a bit more. Other animals will take advantage of the situation, particularly spiders, but you’d be amazed at the variety. I regularly get baby Hemidactylus turcicus geckos that stalk both Sarracenia and Nepenthes pitchers in search of an easy meal, and they also don’t complain about having a good hiding locale in the middle of the day. I’ll just start worrying when I find fence swifts and other lizards in there, too.

Introducing Hemidactylus turcicus

As mentioned for a while, we have a lot of Mediterranean geckos (Hemidactylus turcicus) in the Dallas area. As can be told by the name, they’re not native in the slightest: they apparently arrived in the US in Florida on potted plant shipments, and they’ve been steadily moving west since the 1950s. The first time I ever noticed them was in 1990, where large adults were taking advantage of porch lights on an old apartment of mine to snag insects. Today, they’re all over Dallas, where they’re usually only noticed when they wriggle away from approaching humans on brickwork and stucco walls.

For the ophidiophobes out there, the Medgecko is a much better neighbor than the Tokay gecko (Gekko gekko), which has tried and failed many times to become acclimated to the Dallas area. (Back in the Eighties, a popular suggestion for dealing with cockroach problems in apartment buildings was to buy Tokays and then let them loose in the apartment. Not only did this do nothing to the roach population, but those happy new Tokay landlords discovered that they had a beast that bit and bit hard when approached. Tokays also have the charming habit of getting directly over a person on a ceiling or wall, barking loudly, and then crapping on the eager upturned face trying to identify the noise. I’ve heard of Tokays becoming dog-tame, but I’ll believe it when I see it: I’ve had too many encounters with them.) H. turcicus is very skittish around humans, and most encounters with one consists of hatchlings getting into a house in search of new territory. A Medgecko may spend its entire life in a territory about three meters from where it was born, and most of its species’ prodigious migration is due to females laying their eggs on moving trucks and shipping containers (the eggs actually glue themselves to the chosen surface), where the hatchlings emerge hundreds or thousands of kilometers away from the place of their laying. In Dallas at least, they don’t compete with indigenous geckos, and they do keep the bugs down a bit.

However, there’s always the joy of finding one inside, such as when the Czarina found a big adult in her bathtub a while back.

Hemidactylus turcicus

See the little dark patch in his abdomen? That’s his liver. H. turcicus is translucent enough that it’s possible to make out internal organs and stomach contents, and if you should be in front of a pane of glass on which one is resting, it’s actually possible to see its little heart beating. The translucency gives an idea of how delicate they are: many people come across them after they’d been captured by the local cat, usually with a leg or two broken and the tail removed. (The tail isn’t a big deal, as it auto-sheds at the slightest touch. It’s very rare to find a large one like this with a complete tail with proper markings, and most have tails the color of stale egg nog.)

Hemidactylus turcicus (closeup)

And before you ask, this little guy went back outside where he belonged. He couldn’t escape the bathtub, and now he’s ensconced in the greenhouse with others of his kind. Let them fight their war with the orbweaver spiders with one additional warrior.