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FIGURE 1 Honey bees (Apis mellifera, blue line) and yellowjacket wasps (Vespula vulgaris, red line) both maintain their nests at temperatures that fluctuate less than outside air temperatures (black line). At cool outside temperatures, as here, the nests are kept warmer than ambient. Note that the honey bee colony, with tens of thousands of workers, achieves more precise temperature homeostasis than the wasp colony, with only hundreds of workers. (Data from H. Kemper and E. Dohring, 1967, Die Sozialen Faltenwespen Mitteleuropas, Parey, Berlin.)

FIGURE 1 Honey bees (Apis mellifera, blue line) and yellowjacket wasps (Vespula vulgaris, red line) both maintain their nests at temperatures that fluctuate less than outside air temperatures (black line). At cool outside temperatures, as here, the nests are kept warmer than ambient. Note that the honey bee colony, with tens of thousands of workers, achieves more precise temperature homeostasis than the wasp colony, with only hundreds of workers. (Data from H. Kemper and E. Dohring, 1967, Die Sozialen Faltenwespen Mitteleuropas, Parey, Berlin.)

have colonized much of the temperate zone as well. These honey bees are unique among temperate insects in maintaining a high temperature in their nests throughout the winter, even when environmental temperatures are dramatically lower. For example, an A. mellifera colony can maintain a temperature in the center of its winter cluster inside the nest of 35°C, even when the temperature outside the nest is —40°C. The bees accomplish this by clustering together tightly so that the bees themselves, as well as the nest structure (often a hollow tree or wooden beehive) serve as insulation. The bees consume honey as metabolic fuel and contract their large flight muscles to create heat. Bees on the outside do get chilled, but they trade places with bees in the warm interior from time to time. Even when a bee colony is not in a nest, as when they are moving as a swarm to a new homesite, they maintain warm temperatures inside the cluster of thousands of bees.

The environment is not always cold, so temperature homeostasis for a bee colony sometimes involves cooling the nest. Honey bees fan their wings to move outside air through a colony to remove excess metabolic heat (and carbon dioxide). When this does not cool the colony enough, the bees begin to collect water and evaporate it within the nest to provide cooling. Also, when the nest becomes too warm, many bees leave the cavity and cluster outside the nest, reducing the heat input from their metabolism.

Termites

Many species of termites, like honey bees, live in large groups. Indeed, the largest colonies of social insects occur among the termites, some species of which may have several million individuals in a nest. Unlike honey bees, termite workers do not have wings, and so they cannot move air by fanning. Instead, some species of termites rely on the structure of the nest to regulate temperature and humidity. Macrotermes subhyalinus colonies, for example, construct tall "chimneys"

on their nests. These chimneys are thought to increase airflow in two ways. As the metabolic heat of the termite colony (and the fungus gardens that they cultivate in the nest) warms the air in the chimneys, it rises and is replaced by cooler air from passages near the ground. Also, when wind blows across the open tops of the chimneys, the Bernoulli effect causes lower air pressure at the chimney top and draws air upward.

The climate-control nest structure of another species of Macrotermes, M. bellicosus, was described by Martin Luscher. These termites build nests with a closed-circuit air circulation system. Air warmed by metabolic heat rises in central galleries of the nest but then enters channels on the outer ribs of the nest. Here, it loses heat to the outside through the nest material, and the denser, cooled air settles to chambers at the base of the nest, from which it is drawn to replace the rising air in the central nest, over and over again. As the air passes through the thin outer channels, carbon dioxide diffuses out and oxygen diffuses inward. This system allows gas exchange and cooling, while limiting water loss.

In Australia, Amitermes meridionalis nests are constructed as flat towers, always oriented with their long axis north and south. The result is that they are warmed by sun as it rises in the east early in the morning and strikes their broad side, but they receive relatively little sunshine at midday when the sun is in the north and strikes the nest edge on. These termites are known to sense the earth's magnetic field and use it to coordinate the nest-building activity of the colony's many workers to achieve this striking geographic orientation of the nest.

Tent Caterpillars

Although less organized in their social behavior than most social insects, tent caterpillars use some of the same thermal strategies to get a jump on the warm season. The larvae of tent caterpillars cluster together and form tents from silk that they produce. A group of caterpillars clusters together inside the tent during the night, where both the tent and the presence of many clustered insects reduce heat losses. The higher temperatures that the caterpillars experience allow them to develop more quickly than they would if they were isolated and exposed to the low temperatures that are common, especially at night, in their environment. Tent caterpillar behavior is adapted to keeping with the group. They find their way back to the tent by trails of odors and silk that are laid down as the caterpillars move from the tent to the foliage on which they feed during the day.

Beekeeping for Beginners

Beekeeping for Beginners

The information in this book is useful to anyone wanting to start beekeeping as a hobby or a business. It was written for beginners. Those who have never looked into beekeeping, may not understand the meaning of the terminology used by people in the industry. We have tried to overcome the problem by giving explanations. We want you to be able to use this book as a guide in to beekeeping.

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