General Structure

The more anterior (pregenital) segments are little different from the typical secondary segment described in Section 2. In the first segment, however, the antecosta of the tergum bears internally a pair of phragmata to which the metathoracic dorsal longitudinal muscles are attached. Furthermore, the acrotergite of this segment forms the postnotal plate of the metathorax. Frequently the antecostal region and acrotergite are clearly separated from the rest of the tergum and form part of the metanotum. In the higher Hymenoptera the entire first segment, the propodeum, is fused with the metathorax and the conspicuous "waist" of these insects occurs between the first and second abdominal segments.

The genital opening (gonopore) is located, in the majority of Pterygota, on or behind the eighth or ninth sternum in the female, and behind the ninth sternum in the male. In Ephemeroptera and most male Dermaptera paired gonopores occur. The genital segments are modified in various ways for oviposition or sperm transfer. In female Diptera, Lepidoptera, and Coleoptera the posterior segments lack appendages and form smooth cuticular cylinders often telescoped into the anterior part of the abdomen. When extended (Figure 3.29) they form along narrow tube that facilitates egg laying in inaccessible places. Sometimes the tip of the abdomen is sclerotized for piercing tissues. In other orders the tergum and sternum

FIGURE 3.29. Abdomen of the house fly extended. The segments are numbered. [From L. S. West, 1951, The Housefly, Comstock Publishing Co., Inc.]

of the genital segments remain as distinct cuticular plates. In the female the sternum of the eighth segment is sometimes enlarged to form the subgenital plate, in which case the sternum of the ninth segment is reduced to a membranous sheet. In the male the tergum and sternum of the ninth segment are distinct but may be greatly modified. The genital segments retain their appendages, which are modified to serve in the reproductive process. In the female they form the ovipositor, and in the male, clasping and intromittent organs.

The postgenital segments include the 10th and, when present, the 11th abdominal segments. In the lower orders where both postgenital segments are present, the 10th segment is usually united with the 9th or 11th segments and it never bears appendages. The 11th segment comprises a somewhat triangular tergal plate, the epiproct, and a pair of ventrolateral plates, the paraprocts. It bears appendages, the cerci, inserted in the membranous area between the 10th and 11th segments on each side of the body (Figure 3.30).

In the majority of endopterygotes there is only one postgenital segment, the 10th abdominal segment. It is usually much modified and has no true appendages. When appendiculate structures are present, they are secondary developments.

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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