A description of measured Insect-Biomasses from samples collected in the Orbroich Bruch Nature Reserve, near Krefeld, using Malaise Insect Traps

The results show that, in the same two areas, sampled in the years 1989 and 2013, there was a dramatic fall in the number of flying insects. Using the same traps, in the same areas, significant reductions of insect populations, of more than 75%, were found. Our data confirms, that in the areas studied, less than 25% of the original number of flying insects collected in 1989, were still present in 2013.

Source:
Sorg, M.; Schwan, H.; Stenmans, W & A Müller. Proceedings of the Krefeld Entomological Society, Vol., 1 (2013), pages 1 – 5