The reason behind the high numbers of insect deaths might be artificial lightning and the subsequent pollution caused by it. A new research done to find the cause of decline in insect population in Germany claims that climate change and pesticides might not be the only reason behind the ever declining insect population in Germany. The research was published recently in the journal Annals of Applied Biology and shows that regions which have a high amount of light pollution, had a very small population of flying insects. Research teams from the Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB) reported that the biomass of flying insects has seen a decline of about 75% . Several studies previously tried to find out the reason behind the drastic disappearance of insects from Germany but were perplexed because climate change and disturbances caused to the habitat could not explain the high number of insect deaths.
The recent study chose to analyse the effect of artificial lighting on the insects. Maja Grubisic, lead author of the study said, “Half of all insect species are nocturnal. As such, they depend on darkness and natural light from the moon and stars for orientation and movement or to escape from predators, and to go about their nightly tasks of seeking food and reproducing. An artificially lit night disturbs this natural behaviour — and has a negative impact on their chances of survival”. Artificial lights attract the insects and causes them to separate from their natural ecosystems which further causes the insects to die from either exhaustion or because they become easy prey. Light pollution also inhibits the development of resistant genes that could potentially prevent them from negative environmental impact.
So we must not only take climate change and other similar factors into consideration but also take light pollution into account for preventing insect deaths. Such excessive decline in the population of insects would not only mean a considerable loss of species diversity but would also affect agricultural processes and major ecosystem services. Less number of beetles, flies, moths and bees would mean less pollination. Changes in population of spiders and aphids will also disturb the interactions between the insects and thus their whole ecosystem. Dr. Franz Hoelker, Head of Light Pollution and Ecophysiology at IGB explains, “Our overview study shows that artificial light at night is widely present and can have complex impacts in agricultural areas, with unknown consequences for biodiversity and crop production. Thus, light pollution should be generally considered as a potential ecosystem disturbance in future studies to identify ways in which practical steps can be taken to reduce environmental concerns.”