Archive for October, 2011

SEND IN THE CLONES

Monday, October 3rd, 2011

With perfect luck, one female aphid could be the ancestress of 5 billion offspring in a single summer season, but aphids never have that kind of luck. These chickens of the insect world are the most popular entree on an all-you-can-eat buffet for a wide range of other six-legged critters. Ladybugs have been known to polish off 40 in an hour. Assassin bugs and lacewings suck them dry, and braconid wasps lay eggs inside their soft and luscious bodies. Less threateningly, ants follow them around to slurp up the honeydew that leaks from their nether orifices.

It’s a bug-eat-bug world out there, with only a few ways to go, evolutionarily speaking — hide, fight back, or outbreed the level of destruction — and no other creature has perfected the breed-early-and-often formula as well as the mild-mannered, plant-sucking aphid. First of all, almost all of them are female, and, unlike honeybees, every female aphid propagates. They are, in fact, born pregnant and ready to beget another round of daughters as few as six days after they are squeezed live from their mother aphids’ loins. Each baby aphid is a clone of a clone of a clone until the community is population-stressed enough to require emmigration. Then winged aphids are miraculously produced. When the flyers are established on a fresh river of flowing sap, those brave settlers produce another round or two (or twenty or one hundred) of wingless daughters, sisters and cousins. Only when the waning autumnal light signals the approach of winter do the last of the season’s aphidoidae give birth to males. Then, for the first time in approximately twenty virginal generations, female aphids engage in sexual reproduction and lay eggs capable of over-wintering in plant litter.

Who wouldn’t love an insect with a story like that? Lots of people, it turns out, are not fans of sap-sucking insects with an almost unstoppable ability to breed. Never mind that a cluster of aphids is sure to bring a host of other interesting characters to the garden, the prospect of propagation run amok is a real and understandable fear. That’s what makes what happened to my golden glow aphids such a strange mystery. They disappeared. After years of colonizing here and there among my heliopsis plants, they were gone for no discernible reason. So, too, were the ladybugs and lacewings that frequented their Honeydew Cafes. I don’t suspect foul play. My neighbors may have looked askance at my fondness for creatures they were more inclined to call plant lice, but relatively harmless eccentricity is well-tolerated in my part of town. I suspect one tiny variable — a want of one thing or a plethora of something else — tipped a balance that sent them elsewhere, like tenants who move on with no forwarding address. The disappearance of my golden glows has joined the list of unsolved questions (What happened to Amelia Earhart? Where is Jimmy Hoffa? Was Lizzie Borden guilty?) that rattle like autumnal seed pods somewhere in the itchy background of my brain.  — Sharron Cohen