Thepanorpoid Orders

is seen. In primitive Nematocera three thoracic and seven abdominal ganglia occur, but 245

all intermediate conditions are found between this arrangement and the situation in the more advanced Muscomorpha where a composite thoracoabdominal ganglion exists. In females the paired ovaries comprise a varied number of polytrophic ovarioles. In viviparous species there may be only one or two, but in the majority of oviparous flies there may be more than 100. In viviparous forms the common oviduct is dilated to form a uterus, and the accessory ("milk") glands produce a nutritive secretion. One to four spermathecae are always present. In males the testes are generally small, ovoid, and pigmented. The short, paired vasa deferentia lead into a muscular ejaculatory sac. Paired accessory glands may occur.

Larva and Pupa. Larvae are usually elongate and cylindrical. Body segmentation is usually distinct, but in a few groups the true number of segments is masked as a result of secondary division or fusion of the original segments. True thoracic legs are always absent, though prolegs may occasionally be present on the thorax and/or abdomen. In primitive Diptera the head capsule is distinct and sclerotized (the eucephalous condition). In most species, however, it is much reduced (hemicephalous) or entirely vestigial (acephalous) (Figure 3.13). The antennae and chewing mouthparts, including horizontally moving mandibles, are well developed in Nematocera. In orthorrhaphous species antennae and maxillae may be well developed, but the mandibles are sickle-shaped and move in a vertical plane. In Muscomorpha the antennae are in the form of minute papillae and the mouthparts are reduced to a pair of curved hooks (the original mandibles). The internal structure of larvae generally resembles that of adults. Dipteran pupae are always adecticous. Pupae of nematocerous and orthorrhaphous species are obtect, whereas those of Musco-morpha are secondarily exarate and coarctate, being enclosed in a puparium, the hardened cuticle of the third larval instar.

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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