What makes jumping beans work

Noteworthy Plants. Biology What Makes Jumping Beans Jump? Why Do Jumping Beans Jump? Will U. Border Patrol Confiscate Jumping Beans? An assortment of Mexican jumping beans.

They are actually the separate sections carpels of seed capsules from the Mexican shrub Sebastiana pavoniana. Showy red clumps of Mexican jumping bean shrubs Sebastiana pavoniana and stately fan palms Brahea brandegeei line a canyon bottom of Sierra de la Laguna in the rugged Cape region of Baja California. During June the ground beneath large jumping bean shrubs is littered with coppery-red leaves and hundreds thousands of larva-bearing carpels. The jumping carpels sound like the patter of rain drops on dry leaves.

Apparently the same species of moth larva inhabits seed-bearing carpels; however, the carpels do not separate into sections as in the true Mexican jumping bean S. Note: According to American Insects by R. Arnett , the jumping bean moth belongs to the Order Lepidoptera, Family Tortricidae, and is listed under the scientific name of Cydia saltitans.

It is listed as Cydia deshaisiana in Volume 3 of Nomina Insecta Nearctica and more recent publications in entomology. They're very real, although they're not really beans and they just roll around a bit rather than actually "jump".

It's the larvae of the jumping bean moth Laspeyresia saltitans that cause Mexican Jumping Beans to "jump". The larvae grow inside the seed capsules not beans of a Mexican desert shrub called Sebastiana Pavoniana.

The adult moth lays its eggs in the developing flower of the shrubs which grow in rugged parts of Mexico and Baja California. The eggs hatch and the larvae eat their way further into the developing flower. There, they start eating the growing seeds. The flower capsules gradually harden with the larvae trapped inside and eventually fall to the desert floor.

The capsules are dark brown and about the size of a piece of uncooked popcorn. Now the larvae have the strange habit of rolling around vigorously inside the capsule causing it to rock back and forth.

Both belong to something called the spurge family, or Euphorbiaceae. For hundreds of years, people living near tamboti trees have put the stuff on darts for hunting large game.

Even a sprinkle of crushed-up tamboti bark can make a stream full of fish go belly-up—like a chemical grenade. In Mexico, traditional hunters and fishermen employed the same strategies with the sap of Sebastiania bilocularis , a lesser-known species of tree that also produces jumping beans. According to Adrian Burton , who wrote about jumping beans for an article last year in Frontiers in Ecology and the Environment , the trees can be so toxic that locals avoid using them for firewood.

The smoke taints food and causes eye irritation. As Winterboer tells it, a friend of his once cracked a tooth while he was on an expedition. The pain was so great, and the friend so desperate, that he allowed the local guides to apply a bit of tamboti sap to the exposed cavity in his tooth.

Like liquid flame, the sap burned the nerve out, effectively achieving the same result as a root canal. How exactly moth larvae cope with such a seriously lethal habitat has not been studied.

Perhaps setting up in a tree with poison blood affords the little guys some sort of protection from predators. According to Peter Oboyski , collections manager for the Essig Museum of Entomology at the University of California—Berkeley, there are species of parasitic wasps that descend upon moth larvae in their seedpod homes, inject their spawn into the beans with alien-like ovipositors, and fly away.

The wasp eggs eventually hatch and start doing what parasitic wasp larvae do—eating their hosts alive. Oh, parasitic wasps , I love you so. Over the next months our squirmy friend lines the walls with a comfy layer of silk.

Just enough air and moisture sneak in through tiny holes in the seed walls. Except for the sweltering desert sun. That heat can dry out and kill our sweet little larva. So, of course, it starts jumping. A few hops out of the sun can mean the difference between life and death.

Inside, the larva is working hard. With its back legs, it grabs onto the silk lining and thrashes its head against the seed wall. The force topples the seed. Researchers think these headbangers aim themselves in the right direction using a finely-tuned sense of temperature.