LAUSR

In nearly every ecological community, most species are represented by a few individuals, and most individuals come from a few of the most common species. Singletons (one individual sampled) and doubletons (two individuals sampled) are very common in moth community studies. In some reports, these specimens are excluded from the analysis once they are considered a consequence of under-sampling or of contamination with tourist species that are just passing through. Throughout 12 nights in 2018 and 12 nights in 2019, two Heath traps, one with an 8 W ultraviolet lamp and the other with a 15 W actinic lamp, were positioned approximately 50 m apart at nine sites of four different biotopes in a mosaic forest ecosystem in the Narew National Park (NE Poland). We were able to differentiate moth assemblages according to the forest biotopes under study and by the year of research. With our results, it becomes more evident that singletons and doubletons sampled using weak light Heath traps should be included in the ecological analysis of Macroheteroceran moth assemblages, and our research strongly suggests that they are an important and consistent element of such a sampling method. We also demonstrate that weak light Heath traps are suitable for building an inventory scheme of moth assemblages in small forest areas and that singletons and doubletons can be crucial elements in long-term monitoring systems.