Tuesday, 9 October 2012

And Bugs By Night

The last post was diurnal invertebrates so I figured I should feature the nocturnal ones now. In general they tend to be predominantly predators that gather around the exterior lights hoping for an easy meal. We have the regular 'fluffies', beautiful Arizona Blond Tarantulas. This one was a little shy. Tarantulas are nocturnal predators that never venture far from their burrows unless it is mating season. In winter they plug their burrows with soil, rocks, and silk and survive in a relatively inactive state. During this time the animals live off stored fat reserves.

A little later she came out of her burrow and showed off her full magnificence. Tarantulas have an interesting defencive capability in addition to venom. Some of the hairs on the top of the abdomen are specialised for defence. These hairs, are tipped with backward pointing barbs. If a tarantula is threatened in any way, it brushes these hairs into the face, paw or other body part of its attacker. Once these hairs are embedded, they are irritating and very difficult to remove because of the barbs.

  A slightly more intimidating predator is the Desert Bark Scorpion, smaller, easier to miss but significantly more venomous. The range of the scorpion is the Sonoran Desert, an adult male can reach just over three inches in length, while a female is slightly smaller, with a maximum length of 2.75 inches. The bark scorpion is particularly well adapted to the desert: layers of fat on its exoskeleton make it resistant to water loss. Nevertheless, bark scorpions hide during the heat of the day, typically under rocks, wood piles, or tree bark. Bark scorpions do not burrow, and are commonly found in homes, requiring only 1/16 of an inch for entry! And it gets better - the bark scorpion is the most venomous scorpion in North America, and its venom can cause severe pain coupled with numbness and tingling in adult humans, typically lasting between 24 to 72 hours. Temporary dysfunction in the area stung is common; e.g. a hand or possibly arm can be immobilised or experience convulsions. It also may cause the loss of breath for a short period of time. Due to the extreme pain induced, many victims describe sensations of electrical jolts after envenomation. Needless to say I took this photo on full zoom :)

  Another scary looking predator that is no where near as dangerous, despite it's name is the Tailless Whip Scorpion. Not actually a scorpion, to many it is still the stuff of nightmares and was featured in one of the Harry Potter movies! They possess medium to poor eyesight, however their pedipalps are modified and inward-adapted for grabbing and retaining prey, much like those of a praying mantis. The first pair of legs are also modified and act as sensory organs, while the animal uses the other six legs for walking. The sensory legs (whips) are very thin, have numerous sensory receptors, and can extend several times the length of body. Typically, the animal holds one of these legs out in front of it as it moves, and uses the other to probe the terrain to the side. But fear not, they possess no venomous fangs and they rarely bite if threatened. Don't be tempted to poke them though as they can grab fingers with their pedipalps, resulting in a thorn-like puncture injury.

And to end with, something less fearsome! This is a Mesquite Twig Girdler and it might not be scary to humans but you can be sure that Mesquite Trees are not keen on this little character! The adults emerge in August as the monsoon season is winding down, mate and then select a mesquite, or sometimes an acacia, as home base. The female then proceeds to chew a ring around a twig, stopping the flow of sap and eventually causing that part of the twig to die. She has prepared a nursery for her offspring, allowing her to lay eggs in the dead part.

Sweet dreams everyone :)

Nature Notes hosted by Michelle from Rambling Woods.


bettyl said...

Eeew! Creepy crawlies are quite beautiful if you don't imagine them crawling on you! Your photos are really great!

Celeste said...

Thanks Bettyl, glad you liked the photos, if not the subject matter! :)

Gaelyn said...

I've seen all but the last at my winter home in Yarnell. Not keen on the bark scorpions. My neighbor has been stung several times with the last incident taking her to the hospital.

Great shots and info.

Loredana Donovan said...

You sure do have and know about a great variety of bugs. Thank you for visiting my blog :)

Rambling Woods said...

Oh great post Celeste and I am happy that I don't have some of these insects here..but am happy to learn more about them from you..Michelle

Celeste said...

Hi Gaelyn,
Yes my neighbour has been stung three times by Bark Scorpions too, not good. Have to be very observant as they are so tiny they get in everywhere. The nearest I got was one just next to my pillow in bed!

Celeste said...

We do Loredana, not everyones favourite I know but I thought it would make a change to write about them :)

Celeste said...

Thanks Michelle, they are a mixed blessing indeed :)

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