Insect Thermoregulation

Physiology and body temperatures of insects.

"From one man's persistent and elegant probing of the temperature biology of bees, we have been led to a deeper understanding of the whole biology of many insect taxa, and of their interactions with ecological and environmental stresses: all who work at the interfaces of physiology, ecology and behaviour have cause to be grateful, and all should certainly read this book." (Trends in Ecology & Evolution) "An outstanding source of information, and can be read with profit and satisfaction by the professional biologist and interested amateur alike." (Nature)

The study of insects at low temperature is a comparatively new field. Only recently has insect cryobiology begun to mature, as research moves from a descriptive approach to a search for underlying mechanisms at diverse levels of organization ranging from the gene and cell to ecological and evolutionary relationships. Knowledge of insect responses to low temperature is crucial for understanding the biology of insects living in seasonally varying habitats as well as in polar regions. It is not possible to precisely define low temperature. In the tropics exposure to 10-15°C may induce chill coma or death, whereas some insects in temperate and polar regions remain active and indeed even able to fly at O°C or below. In contrast, for persons interested in cryopreservation, low temperature may mean storage in liquid nitrogen at - 196°C. In the last decade, interest in adaptations of invertebrates to low temperature has risen steadily. In part, this book had its origins in a symposium on this subject that was held at the annual meeting of the Entomological Society of America in Louisville, Kentucky, USA in December, 1988. However, the emergence and growth of this area has also been strongly influenced by an informal group of investigators who met in a series of symposia held in Oslo, Norway in 1982, in Victoria, British Columbia, Canada in 1985 and in Cambridge, England in 1988. Another is scheduled for Binghamton, New York, USA (1990).

The study of thermoregulation in endotherms has contributed much to the emergence of the concept of control theory in biology. By the same token, the study of tempera ture adjustment in ectotherms is likely to have a far-reaching influence on ideas on the regulation of metabolism in general. The reason for this is that ectotherms, in adapting to the vagaries of a thermally unstable environment, deploy a range of subtle molecular and organismic strategies. Thus the experimenter, using temperature changes as a tool, is well equipped to analyze some of these strategies. This approach has enabled some important mechanisms of temperature-induced adaptation to be elucidated; the most striking of these are the effects on metabolism of changes in the conformation of enzymes and the transfer properties of membranes. Furthermore, there is a vague but persistent feeling among those working in this field that changes in the nervous system will ultimately prove to be the agency by which many of the molecular mechanisms of temperature adaptation are controlled. Should this indeed be the case, a new phase would soon begin in our understanding of the interactions between the systemic and the cellular levels of organization. However, it is not only questions about the causes of temperature adaptation that can provide answers of potential importance to the general biologist; of equal significance are questions as to the meaning of temperature adaptation in a particular organism.

Featuring completely updated chapters, additional authors, and an increased emphasis on alternatives to traditional pesticides, the second edition of Ecological Entomology is the field's leading reference on the role of insects in ecosystems. The authors cover insect growth and development, what they eat, how they reproduce, and how they move in various environments. The book also examines how insects interact with the plant community and how to control insect populations naturally.

Physiology and body temperatures of insects.

All bodily activity is the result of the interplay of vastly complex physiological processes, and all of these processes depend on temperature. For insects, the struggle to keep body temperature within a suitable range for activity and competition is often a matter of life and death. A few studies of temperature regulation in butterflies can be found dating back to the late 1800s, but only recently have scientists begun to study the phenomenon in other insects. In The Thermal Warriors Bernd Heinrich explains how, when, and in general what insects regulate their body temperature and what it means to them. As he shows us, the ingenuity of the survival strategies insects have evolved in the irreducible crucible of temperature is astonishing: from shivering and basking, the construction of turrets (certain tiger beetles), and cooling with liquid feces to stilting (some desert ants and beetles), "panting" in grasshoppers and "sweating cicada," and counter- and alternating-currents of blood flow for heat retention and heat loss. In The Thermal Warriors Heinrich distills his great reference work, The Hot-Blooded Insects, to its essence: the most significant and fascinating stories that illustrate general principles, all conveyed in the always engaging prose we have come to expect from this author.

Advances in Insect Physiology