Segmentation and tagmosis

Fig. 2.8 The major body axes and the relationship of parts of the appendages to the body, shown for a sepsid fly. (After McAlpine 1987.)

For appendages, such as legs or wings, proximal or basal refers to near the body, whereas distal or apical means distant from the body. In addition, structures are mesal, or medial, if they are nearer to the midline (median line), or lateral if closer to the body margin, relative to other structures.

Four principal regions of the body surface can be recognized: the dorsum or upper surface; the venter or lower surface; and the two lateral pleura (singular: pleuron), separating the dorsum from the venter and bearing limb bases, if these are present. Sclerotization that takes place in defined areas gives rise to plates called sclerites. The major segmental sclerites are the tergum (the dorsal plate; plural: terga), the sternum (the ventral plate; plural: sterna), and the pleuron (the side plate). If a sclerite is a subdivision of the tergum, sternum, or pleuron, the diminutive terms tergite, sternite, and pleurite may be applied.

The abdominal pleura are often at least partly membranous, but on the thorax they are sclerotized and usually linked to the tergum and sternum of each segment. This fusion forms a box, which contains the leg muscle insertions and, in winged insects, the flight muscles. With the exception of some larvae, the head sclerites are fused into a rigid capsule. In larvae (but not nymphs) the thorax and abdomen may remain membranous and tagmosis may be less apparent (such as in most wasp larvae and fly maggots) and the terga, sterna, and pleura are rarely distinct.

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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