Salt and Water Balance

Salt and water balance involves more than simply the control of hemolymph osmotic pressure; the relative proportions of the ions that contribute to this pressure must be maintained within narrow limits. The osmotic pressure of the hemolymph is generally within the same limits as that of the blood of other organisms, but it can be increased considerably under specific conditions (by the addition, for example, of glycerol, which serves as an antifreeze during hibernation). Regulation of the salt and water content is obviously related to the nature of the external environment. Insects in different habitats face different osmotic problems. Nevertheless, these problems have been solved using the same basic mechanism, namely, the production of a "primary excretory fluid" in the Malpighian tubules followed by differential resorption from or secretion into this fluid when it reaches the rectum. For clarity the problems of insects living on land, in fresh water, or in brackish or salt water are considered separately. However, considerable similarity in the solution of these problems will be seen.

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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