Tuesday, February 2, 2010

Amazing Nature: Ladybug Weathermen

Here's one for Groundhog Day: In England, scientists have discovered that a particular variety of ladybug is actually really really good at long-term predictions of winter weather. When they hibernate for the winter, they choose their location based on how severe the weather is going to be. If it is going to be a mild winter, they pick a relatively unprotected location. If it is going to be a harsh winter, they pick a secure location deep in some sort of protective structure. Since scientists have noticed this behavior, the little beetles have never been wrong. If we can just figure out how they are doing it, maybe it will give us a few hints on how to improve our long term forecasting techniques.

Monday, February 1, 2010

Amazing Nature: Defending Against the Japanese Giant Hornet

The Japanese giant hornet is a fearsome predator. At nearly 2 inches long and built like an insect body builder, it is a force to be reckoned with. Let's put it this way: yellow jacket:Japanese giant hornet::Hugh Jackman:Andre the Giant. It is also a picky eater and will kill thousands of bees just so it can eat the tastiest bits of each bee. In fact, it is the bane of beekeepers in Japan. A coordinated attack of 2 dozen or so hornets will descend on a hive of European honey bees and destroy it in a matter of hours. The bee stings can't penetrate the hornet's armor and the hornets are quite capable of simply biting the bees in half. When the battle is over, the hornets take some of the honey and whatever tasty bits they feel like and go home. The hive usually doesn't recover.

For some reason, though, this isn't really a problem for the native honey bees. This is because the native honey bees have evolved an ingenious defense. They know two crucial facts about how the hornets opperate: 1) the raiding party is always preceeded by a scout that returns to the hornet colony with information about the location of the hive and 2) the hornets die of thermal death at 115 degrees F, while honey bees can survive to 118 degrees. So when the scout shows up looking for a likely target, hundreds of bees pounce on the intruder and hold it down. While they are doing this, they frantically vibrate their wings, generating heat. The heat in the pile builds up to 117 degrees or so, killing the hornet. The bees then stumble off to cool down, having saved the colony.