Data from: when night becomes day: artificial light at night alters insect behavior under semi-natural conditions

Light is the most important Zeitgeber for temporal
synchronization in nature. Artificial light at night (ALAN) disrupts the
natural light-dark rhythmicity and thus negatively affects animal
behavior. However, to date, ALAN research has been mostly conducted under
laboratory conditions in this context. Here, we used the field
cricket, Gryllus bimaculatus, to investigate the effect of ALAN
on insect behavior under semi-natural conditions, i.e., under shaded
natural lighting conditions, natural temperature and soundscape. Male
crickets were placed individually in outdoor enclosures and exposed to
ALAN conditions ranging from <0.01 to 1500 lx intensity. The
crickets' stridulation behavior was recorded for 14 consecutive days
and nights and their daily activity patterns were analysed. ALAN impaired
the crickets' stridulation rhythm, evoking a change in the
crickets' naturally synchronized daily activity period. This was
manifested by a light-intensity-dependent increase in the proportion of
insects demonstrating an intrinsic circadian rhythm (free-run behavior).
This also resulted in a change in the population's median activity
cycle period. These ALAN-induced effects occurred despite the
crickets' exposure to almost natural conditions. Our findings provide
further validity to our previous studies on ALAN conducted under lab
conditions and establish the deleterious impacts of ALAN on animal
behavioral patterns.