Insect Systematics Phylogeny And Classification

Tree showing proposed relationships between mosquitoes, midges, and their relatives. (After various sources.)

It is tempting to think that every organism in the living world is known because there are so many guides to the identity and classification of larger organisms such as birds, mammals, and flowers. However, if we compared different books, treatments will vary, perhaps concerning the taxonomic status of a geographical race of bird, or of the family to which a species of flowering plant belongs. Scientists do not change and confuse such matters perversely. Differences can reflect uncertainty concerning relationships and the most appropriate classification may be elusive. Changes arise from continuing acquisition of knowledge concerning relationships, increasingly through the addition of molecular data to previous anatomical studies. This is especially true for insects, with new data and changing ideas on evolution leading to a dynamic classification, even at the level of insect orders. Knowledge of insects is changing also because new species are being discovered continually, particularly in the tropics, leading to revised estimates of the biodiversity of our planet (see section 1.3).

The study of the kinds and diversity of organisms and their inter-relationships - systematics - encompasses two more narrowly defined but highly interdependent fields. The first is taxonomy, which is the science and practice of classification. It includes recognizing, describing, and naming species, and classifying them into a ranked and named system (e.g. of genera, families, etc.) that, in modern systematics, aims to reflect their evolutionary history. The second field is phylogenetics - the study of evolutionary related-ness of taxa (groups) - and it provides information essential for constructing a natural (evolutionary) classification of organisms. Taxonomy includes some time-consuming activities, including exhaustive library searches and specimen study, curation of collections, measurements of features from specimens, and sorting of perhaps thousands of individuals into morphologically distinctive and coherent groups (which are first approximations to species), and perhaps hundreds of species into higher groupings. These essential tasks require considerable skill and are fundamental to the wider science of systematics, which involves the investigation of the origin, diversification, and distribution (biogeography), both historical and current, of organisms. Modern systematics has become an exciting and controversial field of research, due largely to the accumulation of increasing amounts of nucleotide sequence data and the application of explicit analytical methods to both morphological and DNA data, and partly to increasing interest in the documentation and preservation of biological diversity.

Taxonomy provides the database for systematics. The collection of these data and their interpretation once was seen as a matter of personal taste, but recently has been the subject of challenging debate. Similarly, the unraveling of evolutionary history, phylogenetics, is a stimulating and contentious area of biology, particularly for the insects. Entomologists are prominent participants in the vital biological enterprise of system-atists. In this chapter the methods of systematics are reviewed briefly, followed by details of the current ideas on a classification based on the postulated evolutionary relationships within the Hexapoda, of which the Insecta forms the largest group. The topics of how entomologists recognize insect species and the relationships of hexapods to other arthropods are covered in boxes.

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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