Yellow Blog, Up High in Banana Tree

I love the beautiful world at night.

Tuesday, May 03, 2005

The Clone Wars.

Yesterday, I took Beanie to Bothell Landing Park and watched the mini-Serengeti predator-prey drama going on in the rose bushes by the playground.

Lots of plant-eating bugs like to eat roses. There were a few hard-to-catch blue leafhoppers on these particular bushes, but aphids were by far the most common herbivores present.

I've always found aphids sort of gross -- I favor their other name, "plant lice". They hurt or kill many plants, little plant-sucking vampires that they are. All the same, they're fascinating little beasties. A fellow named Shawn Olson takes great photos of them; behold the aphid ballet! Olsen captures a grace and beauty that I never thought aphids had.

There's several neat things about aphids. First, there's their life cycle. After hatching from eggs in the spring, female aphids start prolifically giving live birth to baby clones. Not just baby clones, mind you, but baby clones who are already pregnant with more clones. You can see how quickly aphid populations can take off:

The French naturalist Reaumur during the late eighteenth century calculated that if all the descendants of a single aphid survived during the summer and were arranged into a French military formation, four abreast, their line would extend for 27,950 miles, which exceeds the circumference of the earth at the equator!

One week, you see a couple of innocuous little bugs here and there on your plants; come back in a week, and the stems are covered with them.

Another cool thing about aphids is their symbiotic relationship with ants. Many species of ants have a special arrangement with aphids: the ants protect the aphids and help distribute them on plants, and in return, the aphids secrete sweet, sticky poop for the ants to eat. The ants tickle the aphids in order to produce drops of this secretion, called "honeydew". (Though it is, in fact, aphid poop. It's very hard to get this nasty, sticky stuff off your car, as I discovered last summer when I parked under an aphid-infested tree). Their relationship with ants is why some people call aphids "ant cows".

A third cool thing about aphids is that lots of insects like to eat them, so you can watch all sorts of little dramas play out in the rose bushes. Beanie and I found a few aphids (more coming soon!) and their protective ants, but we also found two gorgeous varieties of ladybug, including one spotless dark red variety that looked for all the world like a tiny droplet of fresh blood against the bright green leaf. When I saw these blood-colored ladybugs, I wished that I could take photos like Forrest Cook or Shawn Olsen. Lots of ladybugs were preparing for the upcoming aphid explosion by having sex. I had to explain to Beanie why so many ladybugs were playing piggyback! ("That's how they make more ladybugs," was all I disclosed, for now.)

There were lots of other predators hanging out, too. We found jumping spiders and crab spiders, who both do not make webs, but instead actively hunt (or ambush) their prey. There were maggoty-looking wasp larvae present. I found a lacewing, too. (Cool close-up of lacewing here.)

But the most common predators were ladybugs. Beanie caught one in the act of eating an aphid. I've heard they can eat up to fifty aphids per day. That's not fast enough to keep up with aphid parthenogenesis, but it's pretty respectable. Hooray for ladybugs! I expect that the next time I look at those rosebushes, they'll be covered with little yellow ladybug eggs.


  • At 12:44 AM, Blogger Forrest Cook said…

    The aphid ballet reminds me of a certain species of firefly that all blink in unison... It's pretty cool to see an entire field of the things blinking in a seemingly random pattern but all simultaneously. I'm too tired to google for the name though.. might be interesting to look into.

    Forrest Cook

  • At 8:26 PM, Blogger Jaded said…

    so, i hate science. have always hated science. but you make it so damn interesting that i can't hate it. so be prepared to start getting sciencey questions because now that i'm interested, there's a lot of stuff i want to know!

  • At 3:34 PM, Blogger Kate said…

    Yeah, Forrest, I've seen those fireflies on nature shows! They're amazing.

    Ask away, jaded! I'm terribly pedantic, if you give me an opening. :-) I'm glad you like my nature ramblings; thanks for reading.


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