NATURAL PERSPECTIVES:

Honeybees have been declining for years, in part due to infestations of tracheal mites, which cause a dysentery-like disease in bees, and Varroa mites, which are external parasites.

Late in 2006, beekeepers noticed bees were leaving the hive and not returning. Larvae were present in the hives, but there were no adult worker bees to care for them. In all other bee disorders, there are dead bees in the hive that can be used to help determine the cause. Not with this new disease, called Colony Collapse Disorder. The bees simply disappear, as though they had lost their way and couldn’t find their way back to the hive.

Scientists have made only slight progress in determining the cause of Colony Collapse Disorder. Researchers at Penn State University have linked the disorder to the presence of Israeli acute paralysis virus. This new pathogen is a prime suspect in the disorder. However, it is not by itself the cause. Other factors, such as exposure of the bees to pesticides in the fields or treatment for mites, may make them more susceptible to infection with the virus. Unfortunately, U.S. beekeepers reported losses of 36% of their hives over the past winter. About a third of those losses were due to Colony Collapse Disorder.

This crisis is making many people more conscious of the importance of honeybees. One out of every three bites of food that we put in our mouths depends upon pollination by bees. Hard-working commercial honeybees are trucked all over the country to pollinate one crop after another. Beekeepers who rent out their hives start with California almonds in February, and move on to grapes, apples, cherries and melons, finishing with New England’s cranberry crop in the fall. The stress of being trucked may be another contributing factor in Colony Collapse Disorder.

In our garden, we have seen very few honeybees so far this year and precious few bumblebees. Squash and pumpkins depend upon bees for pollination. If the bees don’t buzz around the squash blossoms, then pollen isn’t transferred from the male blossoms to the female blossoms. If the female flower isn’t pollinated, it just withers and falls off the vine. That’s what has been happening in my garden.

Apples need bees, too. Although multiple stamens (the male flower part that produces pollen) and a pistil (the female part that accepts the pollen) are present in each apple blossom, a bee is needed to transfer the pollen from stamen to pistil. My Granny Smith apple tree was covered with blossoms this spring, but only about a dozen apples set fruit — a third of what I got last year.

There didn’t seem to be enough local bees to pollinate my garden, so I took matters into my own hand. I decided to try hand-pollination. Now I go into my garden in the morning armed with a Q-tip. I swirl it around the male squash blossoms to pick up pollen, then dab it onto the stigma in the female flowers. Since I began this routine, I’ve been getting much better fruit set. I have done the same thing with my Fuji apple tree, which bloomed later than the Granny Smith and Gala apple trees. The clusters of flowers I hand-pollinated had four and five apples set fruit per cluster, but the clusters I didn’t hand-pollinate had zero to one apples.

I thought it was time for me to read “The Forgotten Pollinators,” a 1996 environmental classic book by Stephen L. Buchmann and Gary Paul Nabhan. This book is the “Silent Spring” of pollination. In it, the authors decry the loss of wild pollinators, which can range from bees to bats to butterflies to hummingbirds. I recommend it highly.

From this book, I learned that tomatoes are pollinated best by bumblebees. Bumblebees perform an active form of pollination called buzz pollination. They grab a tomato flower and vibrate the heck out of it. Honeybees don’t do this. Commercial growers of hot-house tomatoes import bumblebees from the Netherlands to pollinate their tomatoes. At first, they had field workers hand-pollinate the tomatoes using battery-operated vibrators, but they found the bumblebees were more efficient and resulted in greater fruit set at a lower cost.

We have very few carpenter bees and no bumblebees in our yard, so I asked Vic if he would buy me a battery-powered vibrator. I carefully explained to him why I needed it, but he just glowered at me.

Since neither of us wanted to shop for a vibrator, I now give each tomato blossom a flick with my finger as I walk through my garden. It seems to be working because now my tomatoes are setting fruit.

Buchmann and Nabhan offer some solutions for a lack of pollinators in the home garden.

One is planting a flower garden that will attract more pollinators, but we already have many flowers attractive to pollinators.

Another suggestion is eliminating the use of pesticides, but our garden is already organic.

The third suggestion is getting some orchard mason bees, a native wild bee. They can be ordered from Knox Cellars by calling (206) 849-5065 or by visiting www.knoxcellars.com.

I plan to get some orchard mason bees next spring, because I don’t think I’m going to want to play bumblebee and honeybee for much longer.

VIC LEIPZIG and LOU MURRAY are Huntington Beach residents and environmentalists. They can be reached at vicleipzig@aol.com.