Research on 'sound' in mosquito mating has important implications for the fight against malaria

The World Health Organization (WHO) estimates that in 2020 alone, an

estimated 241 million people will be infected with malaria and as many as 627,000 people will die. In January 2022, a research team led by researchers at University College London in the United Kingdom published research results on the 'sound' that is important in mosquito mating.

Hitting the right note at the right time: Circadian control of audibility in Anopheles mosquito mating swarms is mediated by flight tones

We studied the sounds of mosquitoes' mating rituals – our findings could help fight malaria

Mosquitoes carry infectious diseases such as malaria and dengue fever , so they are also called ' the creatures that kill the most humans .' Although malaria vaccines have already been developed and WHO recommends vaccination for children, the effects of mosquito-borne infections on humans are still significant.

In recent years, it has been pointed out that the mosquito habitat and population have changed due to climate change, and in order to reduce the mosquito population, we also conducted an experiment to 'release a genetically modified mosquito incorporating a gene that kills offspring.' It has been.

Large-scale experiment to release tens of millions of genetically modified mosquitoes to be conducted in the United States --GIGAZINE

Meanwhile, a research team consisting of institutions from University College London and Tanzania conducted research focusing on 'mosquito breeding behavior.' The male mosquito finds the female to mate while flying, but it seems that the clue to find the female at this time is 'female flight sound', if the male can not hear the female flight sound It is said that mating will fail.

However, with the hearing of male and female mosquitoes, the sound of each other's flight is too high in frequency to be heard. Therefore, mosquitoes use a physical phenomenon called ' distortion product ' to distinguish each other's flight sounds. Distortion component Otoacoustic emission is a phenomenon in which an additional frequency component is emitted when two sounds stimulate the auditory organ at the same time, and the newly added frequency component does not exist in the original sound. Hmm.

Mosquitoes feel that the opposite sex is flying around, relying on the frequency component generated by the combination of 'male flight sound' and 'female flight sound'. The research team points out that male mosquitoes must also fly in order to hear the flight sound of females using the distortion component otoacoustic emission, and the flight sound they produce must also have an appropriate frequency. doing.

The research team prepared multiple breeders equipped with highly sensitive microphones, and recorded the feather sounds by putting '100 males', '100 females', and '50 males and 50 females' in them. In the incubator, the lighting environment was reproduced in the same way as the natural environment, and the temperature and humidity were also controlled.

From the data measured over several days, it was found that 'males change the flight sound depending on the time zone'. Specifically, in the evening hours, male mosquitoes flapped faster than usual, flapping at '1.5 times faster than female mosquitoes'. The research team states that the sound of a male flying at this flapping speed, combined with the sound of a flying female flying nearby, produces the appropriate strain component otoacoustic emission. In addition, the males change their flapping speed in the same way even in a breeder containing only '100 males', so even if there are no females nearby, the males change their flapping speed according to the circadian rhythm. I also understand.

It seems that males change their flapping speed in the evening, which is also consistent with the evening when mosquitoes make mosquito columns for breeding. It is mainly males that form mosquito columns, and female mosquitoes sporadically enter there, and males who find females early will succeed in mating. It is believed that mosquitoes change their flapping speed only at certain times of the day because they use energy to increase their flapping speed, and if they do it all day, they will run out of energy.

Based on the results of this research, the research team is investigating whether the same phenomenon can be confirmed in wild mosquitoes living in Tanzania. Understanding the role of sound in mosquito mating is important in combating infectious diseases such as malaria, as it also increases the mating probability of 'mosquitoes genetically modified to kill offspring.' The team said.

in Science,   Creature, Posted by log1h_ik