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Tuesday, July 24, 2012

Are you Ready for the ZomBee Apocalypse?

Today, we launched our latest Citizen Science project, ZomBee Watch, in partnership with San Francisco State University. Yes, that's right folks, we want you to become a real life ZomBee Hunter! To inspire you to do so, sit back and relax while I tell you this epic story of zombification!

Dead honey bee parasitized by the Zombie Fly.
Can you see the white maggot emerging from the neck region?

In the darkness of night zombified honey bees (ZomBees) abandon their hives and embark upon a flight of the living dead! These honey bees, Apis mellifera, have been infected by the Zombie Fly, Apocephalus borealis, brethren of the nefarious ant-decapitating flies. 

Female Zombie Fly, Apocephalus borealis, 2.5 mm long
Photo courtesy of Brian Brown

It all starts when a Zombie Fly finds her way into a bee hive and lays her eggs inside of an unsuspecting bee. After a few days, the eggs hatch and the maggots slowly eat the bee from the inside out. Sensing something is amiss (really, really amiss), the ZomBee abandons its hive under the cover of darkness and "drunkenly" flies towards the light (no pun intended). The zombified bee, like real-life zombies, show symptoms of disorientation (not surprising, since the maggots may well have eaten one, if not all of their brains), such as walking in circles, the inability to stand on their legs, and a fair bit of staggering about. Check out this video:


Zombie-like staggering behavior of honey bees

After the sun rises, the stranded ZomBee slowly dies. Left undisturbed, about seven days later up to 13 maggots emerge, alien-like, from the ZomBee and pupate away from the now lifeless body.

ZomBeee with pupa
Photo thanks to John Hafernik, the scientist who discovered
that Zombie Flies are parasitzing honey bees

Zombie Fly parasitism is not new to science. We've known for a long time that these flies parasitize some of our native bumble bees and paper wasps. But now that Zombie Flies have been discovered "infecting" honey bees, scientists and beekeepers alike concerned. How will this affect the honey bee? They have already been contending with such difficulties as Colony Collapse Disorder, Varroa mites, and a plethora of other diseases and infections. Right now, we are waiting to see what the research shows us. How will this new threat affect the beekeepers’ livelihoods and our bee-dependent dinner plates?

Now that you’ve heard my gruesome tale, I am sure you are compelled, by all that is right and good, to become a ZomBee Hunter. For instructions on how to participate, check out our ZomBee Watch website.

Check out the discovery paper co-authored by Museum Curator of Entomology, Brian Brown
A New Threat to Honey Bees, the Parasitic Phorid Fly Apocephalus borealis 

Friday, July 20, 2012

Do Wasps Have Free Will?

We found a new wasp species in the North Campus. The Great Golden Digger Wasp, Sphex ichneumoneous, is an impressively large (approximately one inch long), and active solitary wasp. Although many see a wasp this large and brightly coloredthe orange and black combo usually tells us to "stay away"this wasp is not aggressive and is very rarely observed stinging. Solitary Hymenopterous insects (those in the order Hymenoptera, aka bees and wasps) are not prone to stinging the same way social species are. This is because they don't have a hive to protect.  

Great Golden Digger Wasp feeding on milkweed nectar

The Great Golden Digger Wasp is actually a beneficial insect in our gardens. Here's how: 
  • They are great hunters. Their scientific name ichneumoneous, is Greek for tracker.
  • Adults feed on nectar and are often seen foraging on flowers.
  • When a female is ready to lay eggs, she digs up to six nests in exposed soil.
  • When she is ready, she captures a cricket, grasshopper, or katydid (yay, pest control)! She paralyzes the insect by stinging it, and then takes it to the nest. 
  • When she gets back to the nest, she goes in to check that everything is okay. She then emerges and drags the paralyzed insect into the hole. There she lays one egg on each paralyzed insect.
  • The eggs hatch after two to three days and begin to feed on the paralyzed insect.
  • After a few weeks to many months (depending on the time of year the egg was laid and the weather) the larvae metamorphose into adults and carry on the life cycle.
Free Will Hunting
In the 1980s, cognitive scientists, Daniel Dennett and Douglas Hofstadter, used these wasps' unthinking deterministic (aka pre-programmed) behaviors to illustrate the meaning of free will. As described above, female S. ichneumoneus, check their holes before dragging the paralyzed prey item into it. Scientists tested this behavior in a controlled environment by moving the prey item while the wasp was inside the nest. When the wasp emerged, she would relocate the prey, drag it back to the nest, and then check the nest again (even though she had already done it very recently). The experiment was repeated up to 40 times, and each time the wasp would re-check the nest. 

In Dennett's 1984 book, Elbow Room, he used this behavioral study as an analogy to the opposite of free will (coined sphexish by Hofstadter), i.e. futily repeating the same actions over and over again in a pre-programmed manner. In contrast, we humans have the ability to recognize futile behavior, exercise our free will to change something, and hopefully disontinue futile activities. YAY! He even coined the term antisphexishness, the state of free will.  Try dropping that one in your next conversation with an intellectual and see what happens!






Thursday, July 12, 2012

Bird's Nest Fungi, Exploding Eggs, and Mushroom Soup

Yay! Today I documented the first bird's nest fungus, Cyathus sp., in the North Campus. For months, I have been looking forward to finding these fascinating, weird, and wonderful fungi. When North Campus Director Carol Bornstein told me she had found some, I immediately knew I had to blog about them.

Bird's Nest Fungi with my finger for scale.

As you can see, this fungus looks like a miniature bird's nest with oddly flattened eggs in it. Mycologists refer to them fondly as BNFs, bird's nest fungi. The "eggs" (periodoles to be geeky and precise) are actually packages containing thousands and thousands of spores. When a raindrop, or some other drop of water, hits the periodole it causes a miniature explosion. The spores are released and propelled out of the cup (some spores can be projected over six feet in this manner), and attach to a suitable substrate by means of a special sticky base.  

How'd they get here? Very likely, they hitched a ride in with a potted plant, or on the mulch we spread to suppress weeds and help keep the soil moist.

Look at those lovely periodoles!

BNF and their closely related kin puffballs, earthstars, and stinkhorns all belong to the group of fungi that produce their spores inside of the fruitbody. In contrast, the white button or portobello mushroom, Agaricus bisporus, that you would buy at the grocery store, produces spores on the fruitbody. Next time you are the grocery store, pick up one of these mushrooms and look underneath the cap. If the cap has opened, you will see hundreds of gills. Each of these gills is a place for hundreds of spore producing structures. Unlike BNF, these mushrooms do not need rain for their spores to spread. Instead, when the spores are ripe, they are shot into the small space between gills. Gravity then takes hold and the spore falls down towards the earth. As the spore comes into contact with the air, it is gently carried away, hopefully in the direction of a suitable susbtrate it can attach to and continue the cycle.

Woah, I can't wait to contemplate the spore's amazing journey over my next bowl of mushroom soup!

Thursday, July 5, 2012

What Do Animals Think About Fireworks?

Last night many of us were enjoying the Fourth of July firework displays. Many of our pets were closed up indoors cowering under blankets, hiding under beds, or being generously shut up in bathrooms or garages. But what about the wild animals?

Up to this point in my life, I had never paused to consider how wildlife might react to fireworks. Maybe this is just me, but until I got into work this morning and saw some footage and stills from our camera traps, I had never even stopped to think about it.

Here are the images Sam Easterson sent me:

Did the opossums feel like they were under attack?

video
Or were they going out to enjoy the show?

Sam said, "The Opossums got really agitated by the sound of the fireworks last night. There were a lot of trips in and out of the den around dusk. Then, a little later in the evening, one of the Opossums exited the den with what looks to be 4 or 5 babies on her/his back. They must have gone out to see the show. Or, they were trying to get away from it!"

Did you witness any interesting wildlife behaviors last night, during our explosive celebrations? Drop me a line and let me know what you saw or heard!