Response of Some Night-Flying Insects to Polarized Light
The possibility that night-flying insects may use naturally polarized light as a cue for flight, dispersal, migratory activities and for orientation during movements (at night) has rarely been considered. The reason for this neglect may well be the belief that the amounts of polarized light that are available to insects at night are too small to influence them. During recent investigations on the flight activity of the mosquito Culex pipiens australicus (Dobrotworsky and Drummond) and the moths Plutella xylostella (L.) and Epiphyas postvittana (Walk.), it was found that there are three peaks of flight activity during the lunar cycle (Danthanarayana 1976, this volume; Goodwin and Danthanarayana 1984). Two of these peaks correlated with the degree of polarization of moon light (which increases at the first and last quarters) and the third occurred at the time of full moon when moonlight is more intense, but less polarized. It is not known, however, whether the correlation between the degree of polarization of moonlight and the amount of flight activity is a cause-and-effect relationship. As a preliminary step towards resolving this problem, the response of night-flying insects to polarized light was examined with the aid of light traps, activity-meter studies and by histological determination of the pigment position of superposition eyes of moths. Moths were selected for laboratory experiments because there is much published work in the eyepigment movements of this group (see below); in previous studies more Lepidoptera have been trapped under polarized light than under nonpolarized light (Kovrov and Monchadskiy 1963) and observations on the light-brown apple moth, Epiphyas postvittana, suggested the existence of profound restlessness (Zugunruhe) during the above phases of the moon (unpublished information). Results obtained during these studies, as reported below, confirm that some night-flying insects respond to dimpolarized light to a greater extent than to nonpolarized light of the same intensity.
KeywordsLight Trap Flight Activity Retinular Cell Plutella Xylostella Flight Chamber
Unable to display preview. Download preview PDF.
- Batiste WC, Olson WH, Berlowitz A (1973) Codling moth: influence of temperature and daylight intensity on periodicity of daily flight in the field. J Econ Entomol 66:883–888.Google Scholar
- Chapman RF (1969) The insects, structure and function. The English Universities Press, London.Google Scholar
- Godsmith TH, Bernard GD (1974) The visual system of insects. In: Rockstein M (ed) The physiology of insecta, 2nd edn. Academic Press, New York.Google Scholar
- Kennedy JS, Booth CO (1963) Free flight of aphids in the laboratory. J Exp Biol 40:67–85.Google Scholar
- Kovorov BG, Monchadskiy AS (1963) The possibility of using polarized light to attract insects. Entomol Rev 42:25–28.Google Scholar
- Mazohkin-Porshnyakov GA (1969) Insect vision. Plenum, New York.Google Scholar
- Mani E, Riggenbach W, Mendick M (1974) Tagesrhythmus des Falterfangs und Beobachtungen über die Flugaktivität beim Apfelwickler (Laspeyresiea pomonella L.). Mitt Schweiz Entomol 47: 39–49.Google Scholar
- Pristavko VP, Cherni AM (1974) Effect of air temperature on diurnal rhythm and activity of the lesser apple worm moth. Ekologiya 5:63–66.Google Scholar
- Siegel S (1956) Non-parametric statistics for behaviour sciences. McGraw-Hill, New York.Google Scholar
- Southwood TRE (1966) Ecological methods. Methuen, London.Google Scholar
- Wigglesworth VB (1972) The principles of insect physiology, 7th edn. Chapman and Hall, London.Google Scholar