Summary

All insect muscles are striated, though their structural details vary according to their function. Skeletal muscles can be categorized as tubular (leg and body segment muscles, and wing muscles of Odonata and Dictyoptera), close-packed (wing muscles of Orthoptera and Lepidoptera), and fibrillar (flight muscles of most insects). All skeletal and many visceral muscles are innervated. Each muscle fiber may receive one to three functionally distinct axons, one of which is always excitatory. Excitatory axons may be subdivided into "fast" axons, whose impulses each initiate strong, rapid contractions, and "slow" axons, whose impulses individually cause a weak contraction but are additive in effect, facilitating a graded response in the muscle. Some fibers also receive an inhibitory axon. Most muscles operate in pairs, with one antagonistic to the other so that as one is stimulated to contract the other is passively stretched. Where there is no antagonistic partner, a muscle may be stretched because of the elasticity of the cuticle to which it is attached.

Most insects use six legs during walking (hexapodal gait). Others use only two pairs of legs (quadrupedal gait) but may use the tip of the abdomen as a point of support. On all occasions, however, there are at least three points of contact with the substrate, forming a triangle of support. Stepping movements are coordinated endogenously, though external stimuli clearly can affect the basic rhythm. Jumping, in most insects that use it, is a function of the hindlegs, which are elongate, muscular, and capable of great extension because of the wide angle that can be developed between femur and tibia. In order to obtain sufficient power

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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