MAY
2007

 

 

 

By
Tom Turpin
 
Professor of
Entomology
Purdue University

 

 

 

 

 

5-24-07

Most Bees Not Social Insects

Mention bees and most people think of honey bees or bumble bees. Or both. That's because these insects are large bees and easy to see. They are also social insects that develop high population numbers during the summer growing season. So we see these bees often.

In addition, the honey bee earns its name by producing honey that humans consume. Honey bees are also one of the primary pollinators of many of our crops, including orchard fruits, berries and many vegetables. Add the fact that females of both honey bees and bumble bees are armed with a stinger, which they will use to defend themselves or their nests and "what we have here" are insects that everyone knows.

Bees are classified in the insect order Hymenoptera, which also includes ants, wasps and sawflies. While bees and wasps both sting, and in some instances look much alike, the two groups differ in one important biological aspect. In general, wasps feed their young animal food while bees feed honey and pollen to their young. As a general rule, bees tend to have more hair on their bodies than do wasps. That is because the bees use the hair to collect pollen when they visit flowers.

Humans are aware of the honey bees and bumble, bees but there are lots of other kinds of bees. There are plasterer bees that line their home, a burrow in the soil, with a translucent substance. There are mining bees that also nest in the ground. Some of these brightly colored blue-and-green bees are attracted to people who are perspiring and are called "sweat bees." Leaf-cutting bees earn their name because they line their nests with cut pieces of plant leaves. Cuckoo bees are parasites of other bees. Carpenter bees chew holes in wood for their nests.

All bees, except honey bees and bumble bees, are what are known as solitary bees. That means they do not live in a colony and are not social bees. The female solitary bee establishes her own nest, either by digging a burrow in the soil or moving into a preexisting hole of the appropriate size. She then brings in pollen to provision a cell in the burrow and lays an egg on the food before closing the cell. She, like the "Little Red Hen," does all the work herself.

The honey bee is the best known of the bees and probably gets more credit for pollination of home garden plants and fruit trees than is deserved. In my experience, most of the early-flowering fruit trees near my home are frequented by several types of solitary bees but seldom by honey bees. I have hives of honey bees within 100 yards of the trees. It seems my honey bees are more interested in dandelion blossoms than the flowers on my peach and plum trees!

So, if the honey bee doesn't pollinate our tree and garden fruits, what does? The solitary bees are doing the job -- for instance, the orchard mason bee. This bee is slightly smaller than a honey bee and is a shiny dark blue in color. This insect makes a nest in existing holes in wood. It uses mud to plug the hole at the bottom and cover the hole. The bee provisions the nest with loads of nectar and pollen to feed the developing bee. You can make homes for orchard bees by drilling one-quarter- to three-eights-inch-diameter holes in wood 4x4s. Or you can buy orchard mason bee houses.

Another bee that is a great pollinator is the leaf-cutter bee. These bees are so effective at pollination that alfalfa seed producers buy masses of bee pupae so that adults are available to pollinate the alfalfa crop. Unlike the orchard mason bee, the leaf-cutter bees cut circles out of plant leaves to partition their nests into individual cells. But just like the mason bee, the leaf-cutter bees fill the cells with pollen before depositing an egg.

Unlike honey bees and bumble bees, solitary bees aren't working as a group to provide food for the kids. The solitary bees do the child rearing as a single parent. But they get the job done and, in the process, contribute to fruit and berry production in many home gardens. So next time you are eating strawberries or apple pie, remember to thank the solitary bees for helping supply the raw ingredients.

 

Writer: Tom Turpin
Editor: Olivia Maddox