Effects of light pollution on development rate of the painted lady butterfly (Lepidoptera: Nymphalidae)

Nov 18, 2025Environmental entomology

Light pollution linked to changes in growth speed of the painted lady butterfly

AI simplified

Circadian Biology on OpenScience ↗PubMed ↗DOI ↗OA ↗

Abstract

Butterflies exposed to 24 hours of artificial light at night emerged 1 to 3 days faster than those exposed to 9.5 hours.

Artificial light at night can disrupt caterpillar development and timing of metamorphosis.
Caterpillars exposed to longer durations of light showed accelerated emergence as butterflies.
Exposure to blue LED light may negatively impact butterfly emergence compared to orange or white LEDs.
Reduced levels of melatonin were observed in hemolymph after exposure to blue LED lights.
Orange LED light appears to be less disruptive to the metamorphosis process than blue or white light.

AI simplified

Artificial light at night (ALAN) can disrupt circadian rhythms and phenology for lepidoptera since photoperiod is a dominant cue for their life cycles. The goal of this study was to discover how ALAN exposure affects the timing of caterpillar development into chrysalis and metamorphosis into a butterfly. The painted lady butterfly (Vanessa cardui) frequents Texas from spring through fall. For this project, commercially sourced V. cardui caterpillars were used to study effects of ALAN in controlled indoor conditions, at a constant temperature of 23 °C. Throughout October 2020, April 2021, October 2021, and March 2022, caterpillars were exposed to 0, 9.5, 17.5, or 24 h of 300 lux white light emitting diode (LED) lights, and the days until chrysalis formation and butterfly emergence were observed. The 17.5 and 24 h ALAN light cycles caused butterflies to emerge 1 to 3 days faster than 9.5 h exposure. V. cardui development was expected to be faster under blue versus orange LED lights as their photoreceptors are more sensitive to blue wavelengths. This was tested in July through September of 2022 with exposure to 24 h white, blue, or orange LEDs versus no ALAN. Orange LED exposed butterflies emerged a day or 2 slower than blue or white LED exposed ones. Studies in 2023 with 12 h ALAN from white, blue, or orange LEDs yielded similar results, and hemolymph melatonin was reduced by blue LED exposures. Therefore, orange ALAN seems to be less disruptive to V. cardui metamorphosis than blue or white ALAN.

Full Text

Full text is available at the source.

View full text (PDF) ↗View full text ↗

Effects of light pollution on development rate of the painted lady butterfly (Lepidoptera: Nymphalidae)

Abstract

Full Text

You found one interesting study. We’ll send the next 7.

what lands in your inbox each week:

Recent issues from the circadian biology brief

Abstract

Full Text

Related papers

You found one interesting study. We’ll send the next 7.

what lands in your inbox each week:

Recent issues from the circadian biology brief