Parasitic Insects, Mites and Ticks: Genera of Medical and Veterinary Importance/Introduction

Introduction
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 * The largest blood-sucking parasite of this book, an Assassin-bug; they infest houses and when feeding on people transmit to them the protozoan Trypanosoma cruzi, the causative agent of Chaga's disease. There are schemes to eradicate these insects to improve the welfare of humans.

Purpose
The purpose of this book is to provide an overview of insects, mites and ticks that directly cause diseases of humans and domestic animals, and that transmit organisms causing disease. This book is aimed at those students and practitioners in medical and veterinary health services, and associated biologists and researchers, who need to know about parasites. This information is provided to supplement current text-books of medical and veterinary parasitology. These textbooks typically provide information in chapters on physiology, reproduction, ecology, taxononomy, and so on. In contrast this book provides information mainly by detailed illustrations. These are provided for important genera, across the range of those important to health of humans and domestic animals.

The illustrations can be used as aids for identification to genus level. Examples are also given in the text of species, but care should be taken not to use this to over identify to species level using this book. The criteria for inclusion in this book are those organisms usually taught in courses of medical and veterinary parasitology and dermatology, and of biological parasitology. The laboratory and clinical sessions of such courses may find this book of particular use.

This book is structured to serve as a framework on which further content and edits can easily be contributed. The building block of a genus of parasites should provide the flexibility needed to improve and update this book as an ongoing laboratory manual. Please feel free to contribute to this Wikibook.

Format
Each representative genus is illustrated by a line drawing, with labelled features that are characteristic. All line drawings were made through direct observation of representative specimens from institutional collections and national museums. Also textbook illustrations were used to inform drawing. Supporting contextual information is briefly provided on hosts, disease associations, and also geographical distribution where a useful statement can be made about a restricted range. Glossaries are provided by chapters. They provide information in a progression through the book, so readers will need to do some cross-referencing; also there is deliberate repetition of some key words and concepts in various glossaries.

The emphasis of this book is necessarily at the level of genera of parasites so that a flexible overview of the whole subject can be provided. The number of species within these genera is much too large to cover in any single book. General information is presented to assist readers in understanding how these parasites live, consisting of diagrams of life-cycles and of the relation of these parasites to skin of their hosts.

Supporting information
More detailed information about the biology and relationships to direct parasitic disease or to transmission of pathogenic organisms should be sought in the textbooks in the References for each chapter, also in Wikipedia articles about individual species, or types of disease. Full definition files for all images used in this book can be downloaded from Wiki Commons.

All of the genera described are within the phylum Arthropoda. That is: bilaterally symmetrical invertebrate animals with an external skeleton, numerous limbs with many joints, and with either a clearly segmented body, or with evidence of segmentation during evolutionary history. The genera of relevance to medical and veterinary research and clinical care are the parasitic (or allergenic) forms. They divide into two major groups: the insects (lice, fleas, flies, and blood-sucking bugs) and the acarines (mites, soft ticks, and hard ticks). The important anatomical and physiological differences between insects and acarines are emphasized. Arthropods that are important because of their venom are covered elsewhere by specialist publications. The naming of parasites in this book follows published listings.

The forms of parasitism described are mostly by feeding on blood or other body liquids taken in by the arthropod through the host's skin. This is called ectoparasitism: the parasite feeds at the surface of its host. Some of the parasites burrow within the skin or deeper tissues, and some inhabit organs such as air-sacs or lungs. This is a form of endoparasitism, but note that this term used in the field of parasitology usually implies the helminth worms (nematodes, tapeworms and flukes). Also included in this book are those mites that cause allergies in humans and domestic animals whilst not being parasitic on them.

Classification of these parasites
The list below is a simplified overview of the relationships between the groups of arthropods with genera and species of importance to medical and veterinary parasitology. The taxonomy of these arthropods has areas of continuing variation and controversy; no definitive statement of arthropod taxonomy is intended by this list. This book is an aid to clinical work, not a textbook of taxonomy. The hierarchy of classification of animals goes: Phylum; Class; Order; Family; Genus; and finally the name of a physical living organism given as the unique combination of the genus to which it belongs and its own species name. For example: Haematopinus suis (or Hog-louse, in English language), with the formal Latin name conventionally written in italic script.

Insecta (Class)

.Phthiraptera (Order)

..Anoplura (sub-Order) Sucking lice

..Ischnocera (sub-Order) Chewing lice

..Amblycera (sub-Order) Chewing lice

.Siphonaptera (Order)

...Pulicidae (Family) Cat fleas

...Ceratophyllidae (Family) Chicken-fleas

.Diptera (Order)

..Nematocera (sub-Order)

...Culicidae (Family) Mosquitoes

...Ceratopogonidae (Family) Midges

...Psychodidae (Family) Sandflies

...Simuliidae (Family) Blackflies

..Brachycera (sub-Order)

...Tabanidae (Family) Horse-flies

...Muscidae (Family) House-flies, etc.

...Calliphoridae (family) Blowflies

...Glossinidae (Family) Tsetse-flies

...Oestridae (Family) Bot-flies

...Hippoboscidae (Family) Louse-flies

.Hemiptera (Order)

...Reduviidae (Family) Assassin-bugs

...Cimicidae (Family) Bed-bugs

Arachnida (Class)

.Acarina (or Acari) (Order)

..Astigmata (sub-Order)

...Sarcoptidae (Family) Sarcoptic mites

...Psoroptidae (Family) Psoroptic mites

...Cytoditidae (Family) Air-sac mites

...Laminosioptes (Family) Cyst-mites

...Analgidae (Family) Feather-mites

...Acaridae (Family) Grain-mites

..Prostigmata (sub-Order)

...Demodicidae (Family) Hair-follicle mites

...Cheyletiellidae (Family) Fur-mites

...Trombiculidae (Family) Trombiculids

..Mesostigmata (sub-Order)

...Dermanyssidae (Family) Bird mites

...Macronyssidae (Family) Bird mites

..Ixodida (sub-Order)

...Argasidae (Family) Soft-ticks

...Ixodidae (Family) Hard-ticks

About this book
This book has depended on loans of specimens to draw and photograph, on help of colleagues, and on the accumulated knowledge written in textbooks and research papers, as seen in the reference lists here. Those people within the fields of medical and veterinary entomology are thanked and acknowledged.

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