Honeybees and native bees

This week, I am offering my annual reminder to all serious and well-meaning gardeners concerning our friend the honeybee and his cohort the native bee.

Honeybees and native bees such as bumblebees, sweat bees, orchard bees and a host of others are beneficial in that they dutifully visit our gardens, pollinating blossoms and guaranteeing a bounty of produce. Farmers and gardeners alike are truly dependent on the work that bees do. A recent Cornell University study concluded that the direct value of honeybee pollination to U.S. agriculture is more than $14.6 billion.

Our friends, however, can be greatly harmed with careless applications of pesticides. Insecticides are generally harmful to pests and beneficials alike, but there are ways to use them without harming the honeybees and other beneficials.

Using the right insecticide at the right time and place will reduce bee kills. Most bees are killed when visiting flowers that have been treated with insecticide. This type of exposure, it could be argued, is more detrimental to the bees than if the hive were sprayed directly.

Bees will visit sprayed flowers, sometimes even returning to the hive with contaminated pollen, which then enters the food supply and kills young bees for weeks. A conscientious gardener applies an insecticide so that little or no residue remains on flowers.

Not all insecticides are equally toxic to bees. For example, Rotenone, Dipel (used on cole crops to control certain worms) and Pyrethrum are relatively safe at any time or place. On the other hand, Dursban, Diazinon, Malathion and Cygon, to name just a few, are very toxic to bees.

Formulation is important, too. When possible, choose a granular or soluble insecticide (these are mixed with water) since they are generally safer than wet table powders and dusts.

The time of application is very important when using any chemical. Many chemicals are deadly when first applied, but degrade after a few hours to a safe level. Since bees forage only during the daylight hours, insecticides should be applied in the early evening so that by morning the residues are low enough that risk to bees is low.

Some reasonably safe ones to use in this manner are Carbaryl (Sevin), Endosulfan (Thiogard or Thiodan) and Methoxychlor. Others which have long residuals are Cygon, Dursban, Diazinon and Malathion and should not be used at all on blooming plants.

Note, too, that bees are rarely attracted to leafy plant parts; therefore, sprays on these plants are generally safe to bees, unless, of course, the spray drifts onto nearby flowering plants. Honeybees, however, aren’t the only bees that deserve credit for the useful work of pollinating our crops. This week, I would like to highlight the contributions of alternative pollinators-native bees.

Native bees, pollen bees and solitary bees are general names for a variety of bees such as alkali bees, leafcutter bees, alfalfa leafcutter bees, bumblebees, sweat bees, squash bees, digger bees, orchard mason bees, shaggy fuzzyfoot bees and hornfaced bees.

There are more than 3,500 species of solitary bees in North America. These efficient pollinators often do the lion’s share of pollinating crops. Pollen bees have a number of advantages over honeybees as pollinators. (1) Many are active early in the spring before honey bee colonies grow to large sizes; (2) pollen bees tend to stay in the same crop rather than flying between crops, providing more efficient pollination; (3) because of their faster flying ability solitary bees can pollinate more plants; (4) unlike honey bees, pollen bee males also pollinate crops and (5) pollen bees are usually gentle with only a mild sting.

With the significant decline in the number of honey bees the last few years due to mites and other factors (a 25 percent reduction in managed honey bees in the last decade), it has become more important to study and preserve wild bee populations. Although the number of pollen bees has also declined due to pesticide use and loss of habitat, pollen bees are unaffected by mites and Africanized bees. May can be managed and used in commercial agriculture.

Native bees are a very important part of our ecosystem and play a vital role in pollinating our most important crops. Be aware of them and appreciate them!

Remember, let’s protect and preserve our bee populations; they are critical to our future.

Tim Lewis is a Georgia Green Industry Association certified plant professional, gardening writer, former Perry High School horticulture instructor and former horticulturalist at Henderson Village and Houston Springs. He and his wife, Susan, own and operate Lewis Farms Nursery located on Highway 26, two miles east of Elko, where he was born and raised. He can be reached at (478) 954-1507, timlewis1@windstream.net and at LewisFarmsNursery.com.

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