Several years ago, the local nature center had bulbs in their light fixtures that attracted a large variety of insects to the area. But only on nights when the moon either was not present, or was, at most, half full when observed. On waxing/waning gibbous to full moon nights, though, the number and variety of insects in the area was significantly lower. So much lower that I just stopped visiting the place during bright moonlit nights and focused my attention on moonless to half moon nights for greater success.
Do other light trappers have similar experiences?
Btw, the lights have since been replaced with bulbs that clearly put off far less UV light, so the place is all but a complete dead zone for attracting insects nowadays, but I still make nightly excursions from time to time.
It is said by some people that moonlight attracts insects, they even dive into puddles where they see its reflection, so probably it is right if you experience the same.
I was told by a moth expert that that is the case since during new/near new moons your trapping light essentially becomes the birghtest object in their vicinity. If it were a full moon then your trapping lights would have some contest.
It is possible that certain insects that are attracted to light navigate using the moon and the moon will influence the insects. Scientists aren’t sure about this though.
It’s been my experience too… and I’ll add that it can be used in your favour… On full moon nights, place your moth trap/sheet at the top of a hill or bank, and the tendency to be drawn to the moon will have insects congregate more near the higher parts of the canopy, ie the top of the hill!