Why are blue-green or white night lights often worse for insects than redder light?

Answer: Insect-sensor match

Higher heat output — No. Blue-looking light is not automatically hotter for an insect in the ecological sense. LEDs can be cool to the touch yet strongly disruptive because their photons match visual or photoperiodic sensors. Heat and light can interact in cities, but spectrum effects can appear even when illuminance is controlled. The clue is that red, green, and white lights at similar low lux can still produce different diapause responses.

Insect-sensor match ✓ — Correct. Many insects are especially sensitive to ultraviolet, blue, green, or broad white light, so spectrum matters as well as brightness. Experiments with 6116 moths found short-wave radiation, especially UV and blue, attracted far more individuals than longer wavelengths. Diapause studies also found red light often causes weaker disruption than white or green. Species differ, so there is no magic color, but blue-rich glare is a risky ecological default.

False nectar color — Not really. Some insects use flower color and scent when foraging, but streetlight disruption is not mainly a fake-nectar trick. Night lighting affects orientation, activity, reproduction, and seasonal clocks. A flower cue would be local and food-specific; blue-green light sensitivity is a broader sensory issue. That is why the same spectrum can affect moth flight, mosquito timing, and other insect behavior.