WIGGLESWORTH, SIR VINCENT (BRIAN)

born April 17, 1899, Kirkham, Lancashire, Eng. died Feb. 11, 1994, Cambridge, Cambridgeshire English entomologist, noted for his contribution to the study of insect physiology. His investigations of the living insect body and its tissues and organs revealed much about the dynamic complexity of individual insects and their interactions with the environment. His Insect Physiology (1934) is often considered the foundation for this branch of entomology. After military service in France during World War I, Wigglesworth completed his education at the University of Cambridge and St. Thomas' Hospital in London. He lectured in medical entomology at the London School of Hygiene and Tropical Medicine and later was reader in entomology first at the University of London, then at Cambridge. In 1943 he was appointed director of the Agricultural Research Council Unit of Insect Physiology in Cambridge. He was knighted in 1964. Among Wigglesworth's most significant discoveries were those concerned with metamorphosis, particularly the control of form and growth. In insects such as the South American blood-sucking bug Rhodnius prolixis, Wigglesworth was able to determine that a crucial growth hormone was produced in the neurosecretory cells of its brain, the first experimental demonstration of the function of such cells. He then discovered another hormone that actually prevented the development of adult characteristics in R. prolixis until the insect had reached the appropriate larval stage. Wigglesworth found that this hormone, which he called the juvenile hormone, was produced in the region of the endocrine gland known as the corpus allatum. He found that he could radically distort the developmental phases of his insect subjects by a selective manipulation of their hormonal levels. Finally, Wigglesworth was thus able to formulate a coherent theory of insect metamorphosis involving the selective activation by hormones of the insect's genetic components, which in turn determine its morphology and developmental character. Besides making these discoveries, Wigglesworth isolated the properties of various insect enzymes and the mechanism for the hatching of insect eggs.