Holy Frijoles!

I know that Mexican jumping beans jump because of worms or larvae inside, but what kind of beans are they, and what kind of worms? What happens to the worm? Does it hatch out as a bug or moth or something, or what?

You’re thinking: Boy, really working hard today, aren’t you? Come on, you never heard of the lazy days of summer? Here’s the sum total of what I know about Mexican jumping beans:

1) As a kid I was completely creeped out by the thought of a bean being eaten from the inside by a hungry bug that might break through at any moment and start in on my hand. It was no comfort to come back the next day and find that the bug had escaped from the bean by means of a perfectly circular hole and was now on the loose in the house.

2) Actually, there was one thing worse: the scene in Pinocchio where Pinocchio and his buddies smoke, drink, engage in wanton destruction, and then turn into donkeys. Saw it again a few years back, and it still made my skin crawl.

3) OK, the science. The bug inside the bean is a small gray critter known as the jumping bean moth, Cydia saltitans. The bean is not a bean but a section of a seed capsule from the jumping bean shrub, Sebastiana pavoniana. (Some say Sebastiana palmieri. Whatever.) The mama moth deposits its eggs on the ovaries of this shrub, which grows on hillsides in the Mexican states of Sonora and Chihuahua and in Baja California. The eggs hatch and the larvae bore into the seedlets and consume the seed inside. According to the natural-history page “Wayne’s Word” ( waynesword.palomar.edu/plaug97.htm ) , “the robust, yellowish-white larva” indulges in “the peculiar habit of throwing itself forcibly from one wall to the other, thereby causing the jumping movements of the capsule.” One explanation is that this helps scare away birds, but we might just as well credit the dawning realization on the part of the larva: “What the f—?! I’m inside a bean!”

4) Just so we’re clear on this, the larva doesn’t exit the unbean until it has metamorphosed into a moth. Doesn’t it seem like a waste that it should go to the trouble of transforming its entire body, only to turn into a stupid moth? Now you know how the ‘rents felt after spending all that money to send you to art school, only to have you wind up a CPA.

5) Mexican jumping beans are rarely sold as novelties in Mexico.

6) A substantial portion of the world’s Mexican jumping beans emanates from one Mexican town, Alamos. (Alamo means cottonwood, by the way. Haven’t you always wondered?) The locals supplement their income by harvesting the seed capsules from the surrounding slopes and listening for the rustling noise they make. The hills are alive, one enthusiast gushes, with the sound of brincadores (jumpers). Dunno about you, but I say: bleagh.

Related Posts

Leave a Reply