Light pollution has many adverse effects on nature and the animals around us. However, a new study found that it has a significant effect on many insect species. Osaka City University and Setsunan University have jointly investigated the impact of expanding urbanization on some insect species, specifically Sarcophaga similis flies. Urbanization has 2 main effects, increasing night lighting and temperature. These 2 effects cause insect hibernation to be significantly delayed.

Light pollution disrupts the hibernation of insects

“The study looks at a species of flesh fly called Sarcophaga similis, but the results could be applicable to any animal species that relies on predictable environmental signals for biological processes like growth, reproductive behavior, sleep, and migration”, said Assistant Professor Ayumu Mukai of Setsunan University and lead author of the study. In collaboration with Professor Shin Goto of Osaka City University, their findings were published in the Royal Society of Open Science.

The increase in light intensity and temperature will have a significant effect on the biological processes of insects, especially on their growth and development. Insects are very disoriented near the urban environment and do not know when to go to sleep, when to migrate and how to behave. The natural biological response to seasonal changes, which are shorter and longer days, is completely changing. This ability is called photoperiodism, and due to night lighting, this reaction is very disturbed.

“Recognizing the conditions urbanization brings upon insects where they actually live would be a great step forward in mitigating any negative effects”, Shin Goto said.

What did the experiment show?

The scientific experiment was performed in both indoor and outdoor conditions. S. similis flies go into hibernation normally during autumn. After increasing the temperature and lighting, the amount of hibernating insects decreased. While under normal conditions the flies begin to hibernate between October and November, after the temperature and light increased, they did not go into hibernation until November.

While night lighting helps people, it is very harmful to insects because it disrupts their natural biological cycles.

“Urban environments are complex, with nighttime illumination and temperatures varying within the same neighborhood and between different cities”, Ayumu Mukai pointed out, “and our work on a single flesh fly does not elucidate the photoperiodic response of other insects.

”To understand the extent to which our cultural life influences other organisms, Shin Goto continued,“ Future studies with a variety of insect species at different sites, in cities with different climatic regions would clarify what levels of light pollution and urban warming affect insect seasonal adaptation ”