Relationship between UV-B radiation of the Sun and the light trapping of the European corn borer (Ostrinia nubilalis Hbn.)

Biological systems are extremely sensitive to changes in ultraviolet radiation reaching the Earth's surface. Atmospheric ozone absorbs considerable part of the UV radiation coming from the Sun and harmful for biosphere so only a very small part of it can reach the Earth's surface thus organisms adapted to that intensity. The light-trap success of European corn borer (Ostrinia nubilalis Hbn.) was examined at those nights when during the previous day the UV-B radiation had different intensity. UV-B data used for examination come from measurements in the Keszthely observatory of the Hungarian Meteorological Service by Robertson-Berger UV-Biometers. The light-trap catch data of European corn borer originated from the national light-trap network between 1994-1998. Relative catch (RC) values were calculated from the daily data of UV-B radiation relating to the summer half-year. The daily data were divided with the weighted average values of previous, actual and following ten days. We calculated RC values from daily light-trap results of European corn borer for all observing stations and swarming times. The RC values were categorised into UV-B groups belonging to each day. Three points moving averages were made from average values of the 14 groups with using our own method. We made correlation calculation between the related values of UV-B and RC. Our results prove light-trap catch is low if the values of UV-B radiation are significantly lower considering to the average. Currently we can not explain how the nocturnal insects can take notice of low UV-B radiation measured during the previous day. The RC is similar to the expectable value if the value of UV-B radiation is more than the average, but the RC has a little bit decreasing tendency. These results can be well valuable for the plant protection prognostic.