NOVEMBER
1995

 

 

 

By
Tom Turpin
 
Professor of
Entomology
Purdue University

 

 

 

 

 

11-23-95

Bumble Bees Must Meet Bottom Line

Insects, it seems, have managed to worm their way into almost every kind of habitat on the earth. They show up in our art, prose and music. Even economic theory is not immune to an insect infestation.

In his 1990 book "Bionomics — Economy as Ecosystem," Michael Rothschild uses bumble bee biology to support economic theory. Rothschild didn't spend long hours observing the behavior of bumble bees, but entomologist Bernd Heinrich did. Heinrich's research focused on how bumble bees gather and use energy.

Bumble bees are social insects that live in colonies ranging in numbers of individuals from dozens to hundreds. The colony members, like in human societies, work together to survive. Over the millions of years that bumble bees have been doing their thing on earth, they have developed a rather special relationship with flowering plants.

A relationship that scientists call co-evolution and Rothschild describes as mutual exploitation. Plants produce flowers that need an insect to transmit pollen from one posy to another, and bees need nectar as a food resource. So in one of nature's little "you scratch my back and I'll scratch yours" schemes, the flower uses a bribe of nectar to entice the bee. The bee carries the pollen in exchange for a sip of nectar. The bottom line, to borrow a budget term, is that bumble bee workers must collect more nectar than they need to survive in order to meet the needs of the colony.

Rothschild states that the life cycle of the bumble bee hinges on a single economic fact. Each worker must gather more energy on each trip to the flowers than it burns in the process. In other words the individual must make a "profit" on each trip. It does this by drinking more nectar than it burns for energy. This means that on some days, when the temperature is cold, bees don't forage because they would burn more energy in the process than they would gain. In other words, they would lose money at that time.

Heinrich found that individual bees become more efficient as they gain experience with certain flowers. So economist Rothschild says bumble bees maximize colony profit by individual specialization — the equivalent of humans becoming butchers, bakers and candlestick makers.

Rothschild even develops a bumble bee hive income statement, something that would warm the cockles of every bumble bee CPA. In the income statement, we find categories such as gross profit per foraging minute, total revenue to the hive, and total gross profit to the hive, all of which is reported in calories. Of course there are overhead costs. Such things as feeding the queen, incubating worker larvae, and disposing of dead workers.

The difference between the gross profits and the overhead costs is available for reinvestment, in this case feeding new queens and drones that will continue the species next year. Of course, if there is any sugar left over when winter hits, this is classified as profit not reinvested. I suppose this profit could be divided among the shareholders, but bumble bees haven't carried economics to this level. So do the profits just go to waste? No, in nature nothing is wasted, so some skunk or raccoon comes along and devours the profits. In terms of business corporations and buyouts and such, could this be called a hostile takeover?

 

Writer: Tom Turpin
Editor: Andrea McCann