Blood-sucking insects are the vectors of many of the most debilitating parasites of man and his domesticated animals. In addition they are of considerable direct cost to the agricultural industry through losses in milk and meat yields, and through damage to hides and wool, etc. So, not surprisingly, many books of medical and veterinary entomology have been written. Most of these texts are organized taxonomically giving the details of the life-cycles, bionomics, relationship to disease and economic importance of each of the insect groups in turn. I have taken a different approach. This book is topic led and aims to discuss the biological themes which are common in the lives of blood-sucking insects. To do this I have concentrated on those aspects of the biology of these fascinating insects which have been clearly modified in some way to suit the blood-sucking habit. For example, I have discussed feeding and digestion in some detail because feeding on blood presents insects with special problems, but I have not discussed respiration because it is not affected in any particular way by haematophagy. Naturally there is a subjective element in the choice of topics for discussion and the weight given to each. I hope that I have not let my enthusiasm for particular subjects get the better of me on too many occasions and that the subject material achieves an overall balance.

In the last few decades there has been an ever-increasing component in most BSc Zoology degree courses of cell biology, physiology and genetics, for spectacular developments have taken place in these fields. Some aspects of biotechnology are now also being included. In order to accommodate the new material, the old zoology courses were altered and the traditional two-year basis of systematics of the animal kingdom, comparative anatomy (and physiology) and evolution, was either severely trimmed or reduced and presented in an abridged form under another title. Soon after these course alterations came the swing to modular teaching in the form of a series of shorter, separate courses, some of which were optional. The entire BSc degree course took on a different appearance and several different basic themes became possible. One major result was that in the great majority of cases taxonomy and systematics were no longer taught and biology students graduated without this basic training. We field biologists did appreciate the rising interest in ecology and environ mental studies, but at the same time lamented the shortage of taxonomic skills, so that often field work was based on incorrect identifications. For years many of us with taxonomic inclinations have been bedevilled by the problem of teaching systematics to undergraduates. At a guess, maybe only 5% of students find systematics interesting. It is, however, the very basis of all studies in biology - the correct identification of the organism concerned and its relationships to others in the community.

Medical Parasitology is primarily intended to be an illustrated textbook which provides a review ofthe most important species ofparasite which occur in man; their areas ofdistribution, morphology and development, the typical disease symptoms resulting from infection, epidemiology and also methods of detection and indications for therapy. The main emphasis is on the protozoan and helmin thic diseases; medical entomology has only been covered in connection with the epidemiology of the diseases described here. Parasites sometimes occur exclusively in man (anthropoparasites) and sometimes also in animals (anthropozoonotic parasites). The monoxenous species complete theirdevelopmentinmanorinoneanimalalone (Scheme I). Heteroxenousspecies, which include most of the medically important parasites, develop partly in man and partly in animals in the course of their life cycle. They may even be forced to infect different species so that they can continue their development. This may sometimes be associated with a digenesis, the larval development taking place in one intermediate (Scheme II ®) or in two different intermediate hosts (Scheme III ®, ©), andthesexuallymaturestagedevelopinginanotherhost, the so-called definitive host (Scheme III ®). The importance of the intermediate hosts can vary considerably (see below).

Forensic Entomology deals with the use of insects and other arthropods in medico legal investigations. We are sure that many people know this or a similar definition, maybe even already read a scientific or popular book dealing with this topic. So, do we really need another book on Forensic Entomology? The answer is 13, 29, 31, 38, and 61. These are not some golden bingo numbers, but an excerpt of the increasing amount of annual publications in the current decade dealing with Forensic Entomology. Comparing them with 89 articles which were published d- ing the 1990s it illustrates the growing interest in this very special intersection of Forensic Science and Entomology and clearly underlines the statement: Yes, we need this book because Forensic Entomology is on the move with so many new things happening every year. One of the most attractive features of Forensic Entomology is that it is multid- ciplinary. There is almost no branch in natural science which cannot find its field of activity here. The chapters included in this book highlight this variety of researches and would like to give the impetus for future work, improving the dev- opment of Forensic Entomology, which is clearly needed by the scientific com- nity. On its way to the courtrooms of the world this discipline needs a sound and serious scientific background to receive the acceptance it deserves.