Summary

The nervous system of insects, like that of other animals, comprises neurons (sensory, internuncial, and motor), synapses, and protective glial cells that wrap around neurons to effectively isolate them from the hemolymph. Neurons are aggregated to form nerves and a series of segmental ganglia. In some cases the ganglia fuse to form a composite structure. The central nervous system includes the brain, subesophageal ganglion, and a varied number of thoracic and abdominal ganglia. The visceral nervous system includes the stomatogastric system, unpaired ventral nerves, and caudal sympathetic system. Impulse transmission along an axon and across a synapse is essentially like that of other animals. Individual reflex responses are segmental, though the overall coordination of motor responses is achieved largely within the brain and/or subesophageal ganglion. Insects are able both to learn and to memorize, and, though the physiological/molecular bases for these abilities are not known, it is likely that they occur within the mushroom bodies of the brain.

The endocrine system comprises neurosecretory cells, found in most ganglia, corpora cardiaca, which both store neurosecretion and synthesize intrinsic hormones, corpora allata, molt glands, and, in some insects, the gonads. Neurosecretory hormones, which are polypep-tidic, either act directly on target tissues or exert a tropic effect on other endocrine glands. In other words, the neurosecretory system "translates" neural information derived from environmental stimuli into hormonal messages that regulate a variety of physiological processes. Juvenile (gonadotropic) hormone, for which six naturally occurring forms are known, is a terpenoid compound produced by the corpora allata. Molting hormone (ecdysone) is a steroid resembling cholesterol from which it is biosynthesized.

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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