Monday, October 17, 2011

A return to blogging -or- interesting bug of the week!

As it turns out, moving to the other side of America and starting your PhD program has a negative correlation with posting on your blog.

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But! No longer will this little corner of the internet languish in a state of shameful neglect! I mean, come on I spent like a whole hour making that banner image at the top of the page!

So, without further ado, I resume posting starting now.

For those that didn't know, I moved across the country to begin a PhD in Entomology, with a focus in evolution and development. I previously had a lot of experience with invertebrate zoology, worms in particular, and so I had to start at the very beginning in a few places. In short, to paraphrase my department chair, WSU entomology needed to "make me into an entomologist".

A visual representation of my current state as an entomologist. Image copyright Paul  Franklin

Thanks to this period of intensive learning about insects, I am finding lots of really cool insects that I didn't know existed until now! Thus, this post shall serve as an inaugural voyage of a (hopefully) weekly feature where I write a little bit about whatever insect I am currently obsessed with this week. My friends in the department should chuckle at that line, because I usually subject them to unceasing rants about how TOTALLY RAD  this new insect is....and most of them already knew about it so they just roll their eyes and give me a pat on the head...


This week's insect obsession is the Blister Beetle. Thanks to an offhand comment during my ecology class about their defense capabilities coupled with my obsession with beetles in general, I took a look at what the google machine had to say about them.

As it turns out, completely by chance, the last few weeks have been "blister beetle" days from a few other science-bloggers.

Ted MacRae over at Beetles in the Bush posted two gorgeous pictures of Meloidid beetles from Idaho, along with a brief bit about identification.

Copyright Ted MacRae, 2011
Additionally, one of the many people I follow on my personal Tumblr posted this video today, which highlights  the amazing ecological interactions between a certain species of blister beetle and digger bees. This behavior can also be seen in the David Attenborough series Life in the Undergrowth, in the episode "Intimate Relations".

So, now I have mentioned two things that interest me about this beetle family- their defensive ability and their reproductive interactions with other insects.

The first one is probably my favorite, simply because I am really obsessed with the Alien franchise. Blister beetles contain in their hemolymph (essentially their "blood") a chemical called cantharidin.This chemical is extremely toxic and is caustic enough to cause the skin to blister (hence the name of the beetle family).

Yeah, it essentially has acid for blood

Meloidid beetles excrete this chemical when agitated through a defensive mechanism known as "reflex bleeding", in which the insect secretes some of the toxic blood through membranes in their leg joints, or between cuticular plates.

It looks something like this! Copyright Alex Wild
That's right-when stressed out, blister beetles will release a bright yellow, caustic chemical. And you thought the Xenomorphs were imaginary.

Truth is apparently sometimes the same as fiction
The other cool thing about blister beetles is how some of them trick bees into providing them with a free place to live, and all the food they can eat.

Holy shit, it even looks like the thing from Alien
What you see above is Meloe proscarabaeus. It typically lives in warm meadows in Europe, and is the classical definition of "freeloader". The female beetle will lay an enormous amount of eggs in a shallow burrow near stalks of grass. When her numerous larvae emerge, they will clamber up the nearest stalk and form into a dense mass of writhing larvae.

Kinda like this, yeah
So here is where it gets even more interesting! This mass of baby beetles exudes a pheromone that male digger bees just can't get enough of. It drives them crazy-crazy, and they fly up to this squirming mass and try and mate with it. Obviously this doesn't accomplish anything...except that the larvae swarm all over the poor bee and hang on tight. When the male digger bee eventually DOES find a real female bee and starts getting busy, the larvae make their second to last voyage. The little guys jump ship from the male to the female and then wait for her to fly back to her burrow, where she has supplied her own future young with a large supply of pollen. When she gets home the beetle larvae disembark and hide amongst the bee eggs, where they feast not only on the stored pollen, but also on the baby digger bees.

And you think you had a rough childhood!

TL;DR- Blister beetles have caustic blood and their larvae will eat your babies*
*if you are a digger bee

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