Out of the Blū

Saturday, December 8, 2012

I have poked these guys in the butt before with grass...

I have poked these guys in the butt before with grass. Mostly being clumsy trying to get them back into their holes. They do flip around all crazy! I had no idea that was why, though. COOL!

From the Evolution Facebook page:

Tiger Beetles: Part 2

Previously we covered how tiger beetle larvae live in burrows, waiting for prey to come by. But what if they need to quickly escape? Being in a hole in the ground is suddenly not such a good move - so they turn to wind and wheels.

The larvae of the Southeastern Beach Tiger Beetle (Cicindela dorsalis media), like all Tiger Beetle grubs, are not built for speed. If a threat approaches their head, they duck down or move their jaws, but when their back half is stimulated they call upon a different strategy - they leap into the air, coil themselves up and spin away to safety. Slow-motion videos showed that the larvae actually co-ordinate their jumps with a gust of wind so they can roll - the first example of wind-powered wheel locomotion.

This wind-powered movement is very effective. In some cases grubs could roll more than 60 metres, at speeds of 3 metres per second - the fastest recorded movement for an insect on the ground. In strong winds, they could roll faster than the research team could run. Wind-powered wheel locomotion avoids the pitfalls standard wheel-locomotion has - other animals that turn themselves into wheels (such as the wheel spider) rely on gravity. Using wind power gives a tiger beetle larva the ability to roll uphill.

It's thought this escape tactic developed to escape parasitic wasps like Methoca, which can slip out of the grub's jaws and dive into the burrow. Rolling is confounded by rough beaches, rocks and ridges, and foot traffic appears to have an disastrous effect on Tiger Beetle populations.

To read the paper on this unique behaviour: http://bit.ly/ev3YeN

Photo credit: Harvey & Zukoff, 2011.

https://phys.org/news/2011-03-scientists-wind-powered-wheel-locomotion-tiger.html

http://blogs.discovermagazine.com/notrocketscience/2011/03/25/beetle-turns-itself-into-a-wheel

Friday, December 7, 2012

My MaMaw called them "Chicken Chokers"

These look like the little guys my grandmother taught me how to pull out of the ground with a piece of grass. 🙂 We used to do that for fun. But then we'd put them back so they would be ok. ❤

From the Evolution Facebook page:

Tiger Beetles: Part 1

Picture this: you're a caterpillar, looking for new vegetation to eat. You spy some leaves just past a hole in the ground and make your way over to them. Next thing you know you're being eaten by something so fast you didn't even see it strike.

Tiger beetle larvae have an intimidating appearance, particularly due to their powerful sickle-shape mandibles. After eggs are buried by the female Tiger beetle, the newly-hatched larva begins to extend and improve its burrow. It digs towards the surface, using its mandibles to loosen the soil and its flat head to push soil out of the burrow when it reaches the surface. Each larval stage the larva goes through (3 in total) is accompanied by increasing the burrow. Their flat armoured head helps them blend in with the soil (though they sometimes hide deep out of sight) and hooks on a dorsal hump keep them anchored in the soil. Powerful mandibular muscles give their bite its strength and their eyesight, unlike many grubs, is sharp and accurate.

When something does come near the burrow, the larva launches itself towards it at incredible speed - interestingly, usually throwing its head backwards at its victim. The sickle-shaped mandibles sink in and its prey (sometimes as big as it) is dragged down into the burrow. Larvae have a similar digestive method to spiders, secreting enzymes to break down food before actually eating it. When the liquidized prey has been consumed, any indigestible remains are ejected from the burrow.

Photo credits: Ted C. MacRae (left), Ingo Arndt/naturepl.com (right).

To see larvae attacking caterpillars, click here: http://www.youtube.com/watch?v=zMkEaIZSNDg

http://drshigley.com/lgh/netigers/tiger_biology.htm

http://insects.tamu.edu/fieldguide/bimg129.html

http://beetlesinthebush.wordpress.com/.../anatomy-of-a.../

http://www.buglife.org.uk/.../bugofthe.../Green+tiger+beetle

David Attenborough's Life in the Undergrowth, Episode 4: Intimate Relations.

Black nails!

Black nails! I don't think I've ever just worn black polish. That's a little too goth for me. This one is not plain black - it's got some silver glitter in it. This one is actually Shaun's, but like a good boyfriend he let me use it. 😃

The polish reminded me of a night sky with stars. I have these silver star studs, so I thought I'd slap one on there and call it fancy. LOL I haven't been in the mood for anything that calls for a lot of work lately. While I don't feel like shit, I'm still coughing and making snot like whoa, so I'm not fully 100% awesome at the moment. Oh well.