The bee's knees

The bee is one of the world's busiest creatures: no wonder that in English we have expressions like “as busy as a bee” and “he's the bee's knees” (meaning “he is a very impressive person”). Bees not only collect honey, they make wax for their hives (and for us to use as furniture-polish), they also pollinate the plants they visit, and are therefore indispensable to farmers.

Now a group of scientists at Cornell University in New York State have designed a new way to use bees. The group, led by Joseph Kovach, reports in the current issue of Biological Control how it has created and patented a bee “footbath” that uses the insects for pest-control.

Strawberries, along with many other soft fruits, suffer from grey mould, a troublesome disease that causes fruit to rot. Although the fungus mainly damages the fruit, infection actually starts in the flowers. One effective treatment is to spray these flowers with another fungus, Try choderma harzanium T1295-22. This eliminates the grey mould before the berries form, but causes no harm to them.

Dr. Kovach's system works by putting the Trychoderma into a specially designed tray that is fixed to the entrance to a hive. The tray can be as easily moved and replaced as the tray of a photocopier. The bees pick up the Trychoderma on their legs as they walk out of the hive onto the tray, and deposit it on the flowers they visit as they search for honey.

The researchers say that bee-delivery is nearly twice as effective as spraying, and uses a fraction of the Trychoderma, because the insects deliver it directly to the flowers rather than wasting them on other parts of the plant. This means that bee-delivered Trychoderma offers as much protection as conventional spraying methods. An added bonus is that simply adding a beehive to a strawberry field improves yields by 20—30% because of better pollination, Dr. Kovach has high hopes of extending the use of his system to other fruit.

Bee-lovers need not worry: the actual increased pay-load carried by the bees is very small, and Trychoderma in no way damages their health. Honey lovers need not worry, either: Trychoderma is found naturally in strawberry flowers. In any case, the honey produced during strawberry bloom time is eaten by the bees themselves, the stuff harvested for human consumption is made much later in the year.

The system does have a couple of drawbacks. Bees only fly about in good weather, so if you crop blooms on a rainy day, too bad. And bees are unpredictable: although they can be trained to feed on a particular crop, if they find a sweeter, more attractive flower nearby, they may be tempted away—and your fruit may suffer. A good idea, then, but clearly not the bee all and end all.

Why are bees indispensable to farmers?

What kind of treatment strawberry farmers use to eliminates the grey mould?

What is Dr. Kovach's new system?

What benefits can farmers get from Dr. Kovach's system?

What kind of problem does the new system has not been solved?