1966 - 1969. PhD Scholar, Brunel University, UK.

Funded by the Medical Research Council and ODA.

As the first internal postgraduate research scholar in the Department of Biology of the new University, carried out an internationally recognised bench-mark study of circadian rhythms of flight activity in mosquitoes (cited in many major text-books and in more than 30 research papers).

Research on Circadian Rhythms of Flight Activity in Mosquitoes.

The experimental work was all done between 1966 and 1969, at Brunel University, with much of the analysis and interpretation of results being presented in my doctoral thesis. Flight activity, under controlled temperature and light conditions, was recorded automatically using an acoustic technique. I constructed almost all the special, sound-proof recording chambers and the electronic circuitry for recording the activity of up to 36 individual mosquitoes. Previous studies of mosquito activity had indicated that the sole phase-setting influence of the natural 24h light-dark cycle activity rhythms was light-off (or sunset). The main work, on the day-active Yellow Fever Mosquito, Aedes aegypti, led to the unexpected conclusion that both light-on and light-off have phase-setting effects, and that these effects appeared to reinforce each other in a range of photoperiods coinciding with that of the natural geographical range of the species. In addition to my thesis, this work was published in some detail (Taylor & Jones 1969).

The main Ae. aegypti work was on a long-established laboratory strain of the subspecies aegypti (originally from West Africa some 40 years previously) and confirmatory studies were made on three other strains from Africa (two of which were of the subspecies formosus). The concept was then further investigated by studying fourteen other mosquito species (Ae. punctor, Ae. cinereus, Ae. detritus, Ae. geniculatus, Ae. impiger, Ae. nigripes, Anopheles plumbeus, An. atroparvus, An. farauti, An. stephensi, Culex pipiens pipiens, Cx. p. quinquefasciatus, Cx. torrentium and Coquillettidia richiardii), obtained either from collaborating laboratories (in the UK and Canada), or by making field collections in southern England. The coincidence was found to appear to hold true whatever the origin of the species, and irrespective of whether the species were day-active or night-active. The results were included in my thesis in somewhat of a summary form, and some are given in outline papers (Taylor 1969, 1977a).

Now, 1998, a much fuller analysis has been possible and a summary paper has been submitted for publication (Taylor 1998). The whole work includes what I believe to be a major step forward in the interpretation of the circadian system. This involves a multiclock mechanism, with the difference in circadian periodicity above and below a light threshold being of central importance in time measurement.

PUBLICATIONS -

Taylor, B. (1969a) Circadian rhythms of flight activity in mosquitos (a detailed study of Aedes aegypti and a comparative study of some other species in relation to range). Ph.D. Thesis, Brunel University, 269 pp.
Taylor, B. (1969b) Geographical range and circadian rhythms. Nature, 222, 296-297.
Taylor, B. & Jones, M.D.R. (1969) The circadian rhythm of flight activity in the mosquito Aedes aegypti (L.): The phase-setting effects of light-on and light-off. Journal of Experimental Biology, 51, 59-70.
Taylor, B. (1972a) Laboratory observations on the timing of flight activity in mosquitoes. Paper presented at the 14th International Congress of Entomology, Canberra, 1p (abstract).
Taylor, B. (1977a) Control of flight activity in mosquitoes. Nature, 265, 762.
Taylor, B. (1998) Biological Clocks in Mosquitoes. Website publication opened April 1998.

INTERNATIONAL RECOGNITION
The 1969 paper (Taylor & Jones) has become an international bench-mark study of circadian rhythms of flight activity in mosquitoes, cited in seven major textbooks and review articles (see Citations below). Despite the apparent acceptance of the concept of light-on and light-off entrainment, there have been few other studies using a range of light-dark regimes within the normal 24h framework of the solar day. However, Chiba & Tomioka (1992, cited below) have recently studied Culex pipiens molestus and described their findings of a critical light-to-dark ratio.

Citations
Taylor & Jones 1969
Nayar, J.K 1971. J. Experimental Biology, 54, 745.
Brady, J.S. 1972. J. Insect Physiology, 18, 471
Bregazzi, P.K. 1972. J. Experimental Biology, 57, 375.
Dumortie, B. 1972. J. Comparative Physiology, 77, 80.
Harker, J.E. 1973. In. Biological Aspects of Circadian Rhythms. Ed. J.N. Mills, Plenum, London.
Mattingly, P.F. 1973. In. Insects & other Arthropods of Medical Importance. Ed. K.G.V. Smith, British Museum, London.
Aschoff, J. 1975. Chronobiology, 2, 23.
Saunders, D.S. 1976. Insect Clocks; and 1982, 2nd Edition, Pergamon Press.
Wainhouse, D. 1977. Physiological Entomology, 2, 323.
Carroll, M.K. 1977. Mosquito News, 37, 661.
Saunders, D.S. 1977. An Introduction to Biological Rhythms. Blackie, London.
Engelmann, W. 1978. J. Comparative Physiology, 77, 80.
Aschoff, J. 1979. Z. Tierpsych., 49, 225.
Beeston, D.C. 1979. Animal Behaviour, 27, 292.
Clopton, J.R. 1979. Physiological Entomology, 4, 201.
Beck, S.D. 1980. Insect Photoperiodism. Academic Press.
Cloudsley-Thompson, J.L. 1980. Biological Clocks. Weidenfeld & Nicholson.
Peterson, E.L. 1980. Behaviour. 72, 1.
Peterson, E.L. 1980. J. Theoretical Biology. 84, 281.
Panadian, R.S. 1980. Oecologia. 47, 89.
Bainbridge, C.A. 1982. Pesticide Science. 13, 92.
Chiba, Y. 1982. J. Interdisciplinary Cycle Research. 13, 55.
Smith, P.H. 1983. Physiological Entomology. 8, 73.
Page, T.L. 1985. In. Comprehensive Insect Physiology. Vol.6. Pergamon Press, Oxford.
Sutcliff, J.F. 1986. Canadian J. Zoology. 64, 1041.
Rowland, M.W. 1986. Physiological Entomology. 11, 325.
Tomioka, K. 1987. Zoological Science,Tokyo. 4, 35.
Klowden, M.J. 1990. Experientia. 46, 669.
Eiras, A.E. 1991. Bulletin of Entomological Research. 81, 151.
Chiba, Y. 1992. Zoological Science, Tokyo. 9, 185.
Yee, W.L. 1992. J. Medical Entomology, 29, 784.
Hong, S.F. 1994. Physiological Entomology, 19, 319.

Taylor 1969a
Saunders, D.S. 1982. Insect Clocks. 2nd Edition, Pergamon Press.
Ramsdale, C.D. 1985. Ecological Entomology, 10, 449.

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1998 - Brian Taylor CBiol FSBiol FRES
11, Grazingfield, Wilford, Nottingham, NG11 7FN, U.K.

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