Hostname: page-component-586b7cd67f-t7fkt Total loading time: 0 Render date: 2024-11-25T21:38:48.185Z Has data issue: false hasContentIssue false

Latitudinal and seasonal changes of nocturnal illumination with a hypothesis about their effect on catches of insects in light-traps

Published online by Cambridge University Press:  10 July 2009

John Bowden
Affiliation:
Rothamsted Experimental Station, Harpenden, Herts. AL5 2JQ, UK

Abstract

An account is given of changes in nocturnal illumination at the spring and autumn equinoxes and summer and winter solstices at latitudes between 50 and 60°N. A Relative Trap Index (RTI) was devised to describe changes in light-trap effectiveness and used to adjust catches of Noctuidae and Geometridae for change in trap effectiveness caused by seasonal and latitudinal change in nocturnal illumination at latitudes between 50 and 58°N. When so adjusted, catches were frequently larger in northern than in southern latitudes, not smaller as unadjusted catches show. It is clear that unless light-trap catches are adjusted to allow for changes of illumination, comparisons over time and space, particularly those which involve assumptions about sample constancy, are suspect. Because of the large differences in RTI that may exist between northern and southern traps, particularly in summer and between the summer solstice and other times, it may be necessary to use different light sources at different times of year to maintain a consistent trap sample.

Type
Original Articles
Copyright
Copyright © Cambridge University Press 1984

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Anon. (1961). Explanatory supplement to the Astronomical Ephemeris.—London, H.M.S.O.Google Scholar
Austin, R. H., Phillips, B. F. & Webb, D. J. (1976). A method for calculating moonlight illuminance at the earth's surface.J. appl. Ecol. 13, 741748.CrossRefGoogle Scholar
Bowden, J. (1973). The influence of moonlight on catches of insects in light-traps in Africa. Part I. The moon and moonlight.—Bull. ent. Res. 63, 113128.Google Scholar
Bowden, J. (1981). The relationship between light- and suction-trap catches of Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae), and the adjustment of light-trap catches to allow for variation in moonlight.—Bull. ent. Res. 71, 621629.CrossRefGoogle Scholar
Bowden, J. (1982). An analysis of factors affecting catches of insects in light-traps.—Bull. ent. Res. 72, 535556.CrossRefGoogle Scholar
Bowden, J. & Church, B. M. (1973). The influence of moonlight on catches of insects in light-traps in Africa. Part II. The effect of moon phase on light-trap catches.Bull. ent. Res. 63, 129142.CrossRefGoogle Scholar
Bowden, J. & Morris, M. G. (1975). The influence of moonlight on catches of insects in light-traps in Africa. III. The effective radius of a mercury-vapour light-trap and the analysis of catches using effective radius.Bull. ent. Res. 65, 303348.CrossRefGoogle Scholar
Brown, D. R. E. (1952). Natural illumination charts.—R. & D. Project NS 714–100. 68 pp. Washington, D.C., Dept. of the Navy, Bureau of Ships.Google Scholar
Landolt-Bornstein, (1965). Zahlenwerte und Funktionen aus Naturwissenschaften und Technik, Neue Serie, Gruppe VI, Band I. Astronomie und Astrophysik.—Berlin, Springer-Verlag.Google Scholar
Lawis, T. & Taylor, L. R. (1965). Diurnal periodicity of flight by insects.—Trans. R. ent. Soc. Lond. 116, 393469.Google Scholar
Morrison, L. V. (1976). The movements of the sun, moon and stars in the sky.—6 pp. Hailsham, Sussex, Royal Greenwich Observatory (N.A.O. Technical Note no. 40).Google Scholar
Steck, W. F., Underhill, E. W., Bailey, B. K. & Chisholm, M. D. (1982). (Z)-7-tetradecenal, a seasonally dependent sex pheromone of the w-marked cutworm, Spaelotis clandestina (Harris) (Lepidoptera: Noctuidae).Environ. Entomol. 11, 11191122.CrossRefGoogle Scholar
Taylor, L. R. (1974). Monitoring change in the distribution and abundance of insects.Rep. Rothamsted exp. Stn 1973 (2). 202239.Google Scholar
Taylor, L. R., French, R. A. & Woiwod, I. P. (1978). The Rothamsted Insect Survey and the urbanization of land in Great Britain.—pp. 3165. in Frankie, G. W. & Koehler, C. S. (Eds). Perspectives in urban entomology.—417 pp. New York, Academic Press.Google Scholar
Taylor, L. R., French, R. A., Woiwod, I. P., Dupuch, M. J. & Nicklen, J. (1981). Synoptic monitoring for migrant insect pests in Great Britain and western Europe. I. Establishing expected values for species content, population stability and phenology of aphids and moths.—Rep. Rothamsted exp. Stn 1980 (2). 41104.Google Scholar
Williams, C. B. (1936). The influence of moonlight on the activity of certain nocturnal insects, particularly of the family Noctuidae, as indicated by a light trap.Phil. Trans. R. Soc. (B) 226 (537). 357389.Google Scholar
Williams, C. B. (1948). The Rothamsted light trap.—Proc. R. ent. Soc. Lond. (A) 23, 8085.Google Scholar