Physiology of tsetse flies (Glossinaspp.) (Diptera: Glossinidae): a review

Abstract

AbstractSince no major review of the literature on tsetse physiology has hitherto been undertaken, relevant papers up to the beginning of 1977 are included in the present work. The physiology of Glossina is dealt with under three major headings; reproductive, developmental and nutritional events in the life of this haematophagous and viviparous insect are discussed in relation to general principles of insect physiology gained from the study of other genera. The role of adult maturation and the possible involvement of a sex pheromone in successful mating are considered. The difficulties of studying neuroendocrine function in relation to reproductive physiology in a viviparous insect, where reproductive and developmental events are not always separated chronologically, are emphasised. Nevertheless, the role of the neuroendocrine system in the control of such events as ovarian development, ovulation, parturition, pupariation and metamorphosis is considered, and the contribution that recent work onGlossinahas made to an increased understanding of general principles in this field is discussed. Laboratory observations have demonstrated circadian components of behaviour in Glossina that can influence interpretation of field observations and likewise should influence the design of physiological experiments. Utilisation of nutritional reserves for larval growth and for flight activity has received considerable attention recently. The general pattern seems to be one of rapid mobilisation of blood-meal amino acids and the involvement of a large lipid reserve. The combined haematophagous and viviparous habit ofGlossinahas led to some interesting modifications of basic physiology particularly in regard to flight metabolism, female accessory gland function and Malpighian tubule activity. The relevance of physiological studies to current developments in the field of tsetse control is discussed and the importance of exploiting our knowledge in the quest for novel insecticidal techniques emphasised.