Nature's Killing Machine

This is one insect that is truly scary!

The insect pictured is called Vespa mandarinia, also known as the Japanese Hornet. Colloquially, it is known as the yak-killer hornet. This killer insect is in the Order Hymenoptera, Family Vespidae.

Before getting into the scary details, let's go over the life cycle. Being a hornet, they have a holometabolous development pattern, once again developing from egg to larvae to pupae to adult. Many hornets are eusocial, meaning that they are colonial and dependent on one another to survive. The nest begins each spring by a fertile female. She builds the first 50 or so cells of the nest out of chewed wood then births an army of servants to finish her work.

She lays an egg in each of the cells and after 5-8 days, they hatch. Within the next 2 weeks, the larvae will undergo 5 larval instars, requiring a very proteinaceous diet to do so. The larvae will then spin a silken cap to their cell and metamorph into an adult. The first batch of children are all female. These ladies take over the tasks of running the colony - foraging, taking care of the young, and continued building and upkeep of the nest, and care of the queen. The colony continues to grow until it reaches a peak of about 700 inhabitants! The peak occurs late in the summer and it is at this time that the queen will start producing the reproductive individuals.




An interesting thing to note is that many times in the wasp/hornet world, the males are a result of unfertilized eggs and females from fertilized eggs. This seems like such a strange idea since we're all used to the idea that all eggs are fertilized.

The males do nothing to help with the colony - they simply wait around the colony and get fed by the worker females until mid-autumn when it is time to mate. They take off and pair with a female and then die shortly after they've fertilized a female. (Sounds a lot like women's complaints about their men!) The only purpose of the male is to supply the new queen with sperm to build her army of amazon women. Pretty sad.

The newly fertilized queen goes into hibernation for 6 months to overwinter the cold months and the rest of her forgotten colony is left to die as she begins anew in the spring.

Now let's get on to the horrors of this bug!

This is the world's largest hornet, measuring at 2 inches in body length, and up to 3 inches in wingspan. The Japanese Hornet is regional to temperate and tropical East Asia (mainly mountanous Japan), thank God! Let's pray that another grad student doesn't unleash this terror upon us!

The stinger alone of the insect is 1/4 of an inch long! The pain of this sting has been associated with a white hot nail being driven into your muscle, hitting bone! There are a number of reasons to attribute to this excrutiating pain. One reason includes that the venom has a much higher concentration of acetylcholine. Acetylcholine is a neurotransmitter that stimulates the nerve fibers responsible for pain reception. The venom also contains a neurotoxin called mandaratoxin which over stimulates and overwhelms our pain receptors. And to add the cherry on the sundae, the venom contains a cytolytic peptide. This is flesh eating activity, as in your skin can dissolve from this stuff!

LOL no pictures this time.

As if things couldn't get any worse, the venom also has an odor to it that attracts other hornets to come sting you. And did I mention that, hornets have a barbless stinger so they're able to sting you as many times as they feel like it. Joy...

What amazes me is that their venom is highly potent, but they don't rely on it. The Japanese Hornet is a killing machine in every sense. They are predaceous upon large insects such as bees and praying mantids. Their all time favorite snack is Honey Bee larvae. A handful of these terminators from hell will take on an entire Bee hive, with numbers averaging 40,000.

Any normal animal would think twice before messing with an entire hive of bees, but not the Japanese Hornet. The puny bee sting is no match for the hornet's large mandibles, allowing the hornet to quickly decapitate a honey bee in one fell swoop. This voracious hunter can kill as many as 40 bees a minute, with a handful of them wiping out an entire bee hive in a matter of hours, leaving nothing but a trail of doom and destruction in their wake. (I'll post a video of this at the end!)



Once there are no survivors left, the hornets will feed on the honey in the nest, needing the sugar to power their flight muscles for the long trek back to their nest. While the hornets love the tasty goodness of the bee larvae, they cannot digest it, so they fly the bee larvae all the way home to feed to their own larvae. The larvae digest them and then secrete a clear goey substance that the adult hornets will consume.

Humans are not usually on the menu for the Japanese hornet, but they will attack when provoked. About 40 deaths occur a year in Japan from this nasty little hornet. It would be wise not to piss these guys off as they fly 26 mph, making it impossible to outrun them! So don't do it!

There are no natural predators of the hornet, which doesn't surprise me! However, some humans are brave enough to include the hornet in their diet! Yum...hornet sashimi...I feel sorry for the poor guy assigned the job of hornet collector!

http://www.youtube.com/watch?v=JDSf3Kshq1M

The Japanese Hornet...a beast not to be messed with!