Structure

Adult. Among the living Coleoptera are some of both the largest and smallest of recent Insecta. The scarabaeid Dynastes hercules reaches 16 cm in length, in contrast to many Ptiliidae which are 0.5 mm or less. The head, which is primitively prognathous but sometimes hypognathous, is usually heavily sclerotized and of varied shape. Compound eyes are present or absent; occasionally they are so large as to meet both dorsally and ventrally, and in some Scarabaeoidea and Gyrinidae they are divided into upper and lower regions. Ocelli (never more than two) are absent in most species. The antennae are typically 11-segmented, but their length and form are extremely varied. The mouthparts typically are of the chewing type, but their precise structure is varied. In many species the mandibles are sexually dimorphic, being enormously enlarged and frequently branched in the male. The prothorax is the largest of the thoracic segments and is usually quite mobile. The mesothorax is small and the metathorax relatively large, except in species in which the hind wings are reduced or absent. The fore wings are modified as hard elytra that meet in the midline but are not fused except in species in which the hind wings are lacking. The metathoracic wings are membranous and typically are longer than the elytra beneath which they are folded longitudinally and transversely when not in use. The legs are usually all similar, though one or more pairs may be modified for the performance of particular functions. The number of visible abdominal segments is varied. Basically there are 10 segments, though the first is much reduced, and the last two or three are reduced and/or telescoped within the more anterior ones.

In accord with their varied diet, the alimentary canal shows a range of structure. Basically, however, it comprises a short, narrow pharynx, a widened expansion, the crop, followed by a poorly developed gizzard, a midgut that is highly varied, though usually possessing a large number of ceca, and a hindgut of varied length, Typically four or six Malpighian tubules occur, and in Cucujiformia and most Bostrychoidea a cryptonephridial arrangement exists (see Chapter 18, Sections 2.1 and 4.1). The entire range of concentration of the central nervous system is found in Coleoptera, from the primitive condition in which three thoracic and seven or eight abdominal ganglia can be distinguished to that in which all of the thoracic and abdominal ganglia are fused to form a composite structure. In males the paired testes may be simple, coiled tubular structures (Adephaga) or subdivided into a number of discrete follicles (Polyphaga). Paired vasa deferentia lead to the median ejaculatory duct, into which also open accessory glands of varied number and structure. The ovarioles of females are polytrophic (Adephaga) or acrotrophic (Polyphaga), and varied in number. A single spermatheca and its associated accessory gland enter the vagina by means of a long duct.

Larva and Pupa. The general form of beetle larvae is widely varied, though in all species the head is well developed and sclerotized, and the thoracic and abdominal segments (usually 10, rarely 9 or 8) are readily distinguishable. Thoracic legs are present or absent; abdominal prolegs are absent. Four basic larval types are found, campodeiform, eruciform, scarabaeiform, and apodous (see Chapter 21, Section 3.3.1, for further details of these types). In a few families, for example, the Meloidae, hypermetamorphosis occurs when a larva passes through all four forms during its development. Pupae are always adecticous and in most species exarate, though in Coccinellidae, most Staphylinidae, and a few other groups they are obtect.

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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