Jumping Beans

Staff at the Queensland Museum’s Inquiry Centre were horrified to receive two postcards recently. The pictures were innocent enough - cartoon beans playing leapfrog. The problem was the contents; sealed plastic bubbles containing live Mexican 'Jumping Beans'. Fascinated staff watched as they flipped and twitched.

A Mexican 'jumping bean' postcard

The ‘bean’ is the seed capsule of a tree, Sebastiana pavloviana, a member of the family Euphorbiacae growing in Mexico and southern United States. Each capsule contains the caterpillar of a moth (Cydia deshaisiana), which grows by eating the contents. Every time the caterpillar wriggles the ‘bean’ moves too. When replete the caterpillar pupates inside and emerges as an adult moth.

The caterpillar is a fussy eater. Like most caterpillars, it feeds on only one kind of plant or a very narrow range of closely related species, and may not pose a threat to Australian native plants. However this has not been tested so who can be certain? And what hitch-hikers could be travelling with the caterpillar?

The recent discovery of Red Fire Ants in Queensland highlights the potential threats from importing live organisms.

It is important to note that it is illegal to import such material into Australia. Each year the Australian Quarantine Inspection Service (AQIS) intercepts many thousands of items. The AQIS site has details about Austrlia's laws and procedures as they relate to international travellers and users of the postal system.

It is of concern that live insects are packaged in postcards and distributed globally at the whim of the sender. The cards were colourful and the ‘beans’ were fun, but Museum staff froze theirs at the first opportunity. There are enough problem exotics without another newcomer to keep us on the hop!