Just like the peanut is not really a nut and the pineapple is not an apple, not all ‘beans’ are beans. Perhaps the most remarkable of all the beans-that-are-not-really-beans are Mexican jumping beans which are actually seeds from a deciduous desert-loving shrub (Sebastiana pavoniana) that only grow in some Mexican states (e.g. Sonora and Chihuahua).
Each spring, female moths (Laspeyresia saltitans) deposit their eggs in the shrub’s flowers. Soon, tiny insect larvae hatch from the eggs and burrow into the young flower capsules. There they chomp away inside the developing seed, leaving the undamaged seed wall as their protective fortress.
Once the invader has carved out a comfortable living space, it begins to construct a web along the inner wall of the seed.
Before long, each ‘bean’ comes to life as the plucky little yellowish-white larva throws itself violently against the walls of its chamber, producing the erratic movements that are characteristic of the jumping bean.
If you have never seen them, the good news is you don’t have to risk life and limb traveling to Mexico and fight the jumping bean-collecting gang lords to gather your own. Fortunately, it’s jumping bean season again and they can be acquired from several Internet sources.
One is Mark Harzdorf who has been importing and selling jumping beans since 2007.
As pets go, jumping beans aren’t exactly affectionate or trainable, but they won’t soil the carpet or require feeding. And no expensive vet bills, either. They may, however, demand your attention as the brownish-colored, rock-like objects convulse at random intervals producing an erratic clicking sound in their plastic prisons.
Today’s tech-savvy kids unfamiliar with these little marvels of nature may suspect strange electronic contrivance is behind the beans’ movements. They are usually surprised to learn that not only are they witnessing nature at its most mysterious, but that a little fun can still be had even without battery-operated devices.