(Editor's Note: This article was originally published on November 10, 2008. Your comments are welcome, but please be aware that authors of previously published articles may not be able to promptly respond to new questions or comments.)
Each insect has its own particular way of dealing with cold temperatures during the long winter months. Different species of bees have different ways of coping with the cold, from hibernation to dying and putting energy into future generations. Read on for a more indepth explanation of several different species of bees' survival mechanisms.
Honeybees (Apis mellifera)
Honeybees have a very interesting method of winter survival. Honeybees stop flying when the weather drops below 50 degrees. When the temperature drops below that, the bees all crowd into the lower central area of the hive and form a "winter cluster." The worker bees huddle around the queen bee at the center of the cluster, shivering in order to keep the center around 80 degrees. The worker bees rotate through the cluster from the outside to the inside so that no bee gets too cold. The outside edges of the cluster stay at about 46-48 degrees. The colder the weather is outside, the more compact the cluster becomes .
Hibernating honeybees have been studied and shown to consume up to 30 pounds of stored honey during the winter months, which helps the bees produce body heat. Heat energy is produced by the oxidation of the honey, and circulated throughout the hive by the wing-fanning of worker bees . Note the diagram at right.
On warmer days, bees will venture out for short flights to eliminate body waste. The flights do not last long nor do the bees travel very far because if their body gets too cold they might not be able to return to the hive .
Hornfaced Bees (Osmia cornifrons)
Hornfaced bees are a species of mason bees and are closely related to blue orchard bees. They are native to Japan and were introduced to the United States in 1960. Their distribution in the US includes the East Coast and the Midwest.
Adults live only for about 6 weeks, unlike honeybees. Hornfaced bees, like carpenter bees are solitary bees, which means each female bee makes her own nest and there is no designation between queen and worker bees. Inside the nest, eggs hatch into larvae and feed on pollen provisions left by the mother bee. Each larvae has its own cell and food supply, which are divided by mud partitions. After a larvae finishes feeding on the pollen, it spins a cocoon in which it remains inactive throughout the whole summer. In the fall, the larvae molt into pupae and then into adults. They spend the winter as adults in the cocoon and then emerge in early spring to start another generation .
Carpenter Bees (Xylocopa violacea)
Carpenter bees are named for their nesting technique of drilling tunnels into old wood. During the cold winter months, carpenter bees will find an old nest tunnel in which to hibernate through the winter. In the spring, carpenter bees will emerge and mate.
Once mated, the female bee will find a new suitable spot for a nest and drill into the wood in order to make a nest. She will then excavate a tunnel, which can run up to a couple inches long, and lay her eggs. In the summer, the next generation of carpenter bees will emerge as adults .
Blue Banded Bees (Amegilla sp.)
During fall, blue banded bee adults all die as temperatures cool within their nests. Before they die however, the female bees lay eggs within the nests which become immature bees called prepupae. They remain dormant, burrowed in the nest inside cell sacs throughout the winter months and do not emerge until spring brings warmer weather. Then they finish their development into adults and emerge into the warmth of spring and begin a new season of life .
Bees are very interesting creatures that have individual and specialized systems for surviving naturally through harsh winters.
If you want to read up more on the bugs you see around your area, be sure to check out the BugFiles here at Dave's Garden. You can also visit the Beekeeping Forum here at Dave's with all your questions about beekeeping.
Special thanks to: Melody-thumbnail image of Honeybees; Floridian- Honeybees in hive; begoniacrazii- Honeybee; Philomel- Carpenter Bee; Dinu- Blue Banded Bee on waterlily; UniveralGarden-2 Honeybees