Natures wonders: red light stimulates moth sex (Introduction)

by David Turell , Wednesday, February 24, 2021, 18:48 (1366 days ago) @ David Turell

No explanation of why it is important:

https://www.newscientist.com/article/2268874-moth-species-becomes-more-sexually-active-...

"An Asian-Australian moth becomes more sexually active under red light than under another colour of light or in the dark.

"Dim red light appears to stimulate chemical changes in the antennae of male yellow peach moths (Conogethes punctiferalis), making them more sensitive to the smells emitted by nearby females. This increases their copulation rates, says Wei Xiao at Southwest University in Chongqing, China.

"Xiao and his colleagues made the accidental discovery while studying the general behaviour of the moths, which invade orchards and spice farms across Asia and Australia.

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"his team realised that every time the red lights were on, the moths responded by laying more eggs. So the researchers decided to test the effects of red light on mating.

"They set up four cages, three of which were dimly lit by either red, white or blue light. The last was in complete darkness. Then they placed 30 male and 30 female moths in each cage.

"They found that the moths in the cage exposed to red light mated significantly more frequently and laid more eggs than the moths in the other cages, says Xiao.

"To understand why, the scientists analysed the antennae of male moths that they had raised in conditions with 15 hours of normal light and 9 hours of dim red light. They found that these moths had more odorant binding proteins (OBPs) in the smell receptors of antenna neurons, apparently making them hypersensitive to female sex pheromone odours.

"It is possible that this occurs because red light has a long wavelength that can pass through animal tissue and stimulate cellular activity, the researchers speculate."

Comment: an oddball finding. Does this phenomenon have any real purpose? Real light has a red band, and moths aren't normally bathed only in red light.