As summer draws to a close, some parts of the U.S. are seeing a steady rise in cases of mosquito-borne diseases. In others, malaria is a more constant threat, even as vaccines become more widely available. But new research into how they mate could help researchers improve techniques to control malaria-carrying mosquitoes.
To non-biting male mosquitoes, the female’s high-pitched buzzing is a siren signaling that it’s time to mate, but the signal has more meaning than scientists initially realized. Anopheles When mosquitoes detect the female’s distinctive wingbeat, their vision becomes more active. The study was published in the journal Nature on August 30th. Current Biology.
Finding Weaknesses
Mosquitoes The most dangerous animals on earthThey spread diseases such as dengue fever, West Nile virus and Eastern Equine Encephalitis (EEE). World Health Organization estimates Worldwide, 219 million people become infected each year and more than 400,000 die from the bite of infected mosquitoes.
Despite being extremely dangerous, these insects have a weakness: many mosquito species have poor eyesight. Anopheles mosquitoThis species is the main source of malaria in Africa. Anopheles mosquito.
[Related: Mosquitoes can sense our body heat.]
this New ResearchThe team found that when males hear the buzzing of a female mosquito, their eyes become “activated” and they visually locate a nearby mate. A. Coluzzi Males usually mate in busy, crowded flocks, where they can find their target by sight, then increase their flight speed and maneuver around the flock, avoiding collisions with other males.
“We found this incredibly strong connection when male mosquitoes were searching for a mate. They heard specific wing-beating sounds (like those made by females) and this stimulated their visual system,” said study co-author Saumya Gupta, a biologist at the University of Washington. It said in a statement“This indicates a complex interplay between the mosquito’s different sensory systems.”
With this new understanding of how well their sensory systems pick up the sounds and sights of their mates, scientists may be able to develop a new generation of traps tailored specifically for this species. Anopheles mosquito Malaria-transmitting mosquitoes.
“The sound is very attractive to the males, and they make their way toward what they think is the source of the sound, which could be a female or a mosquito trap,” says study co-author Jeffrey Riffel, a biologist at the University of Washington. It said in a statement.
Mosquito Flight Simulator
Some Anopheles mosquito seed Mating in large groups at sunsetMost of the insects in a swarm are male, with only a few females, and the males must use all of their senses to avoid conflict and find a mate.
To better understand how male mosquito senses work together in chaotic swarms, the University of Washington research team collaborated with scientists from Wageningen University in the Netherlands, the Institute of Health Sciences in Burkina Faso and the University of Montpellier in France.
team Built a miniature arena It uses a curved, pixelated screen to mimic the visual mayhem of a swarm and test how individual male mosquitoes fly. According to the teamThe arena was essentially a flight simulator for mosquitoes: the mosquitoes were tethered and couldn’t move freely, but they could still see, smell, and hear while flapping their wings as if they were flying. They performed their tests with dozens of male mosquitoes. Anopheles mosquito mosquito.
They found that males responded differently to objects in their field of vision depending on the sounds made in the arena.450 HertzWhen the team played a sound with the same frequency as a fellow male’s wing flapping, the male moved toward the object.700 Hertz), male mosquitoes did not move toward the object.
moreover, Mosquito Perception Distance Distance to the object also mattered: if the simulated object appeared to be more than three body lengths away, he did not head in its direction, even if it was making female-like flight sounds.
“The resolution of a mosquito’s eye is about 1,000 times lower than that of a human eye,” Riffel says, “so they tend to use their vision for more passive behaviors, like avoiding other objects and controlling their position.”
In the arena experiment, males Minor flight adjustments were madeThey changed the amplitude and frequency of their wing beats in response to objects in their field of vision, even when they couldn’t hear the wing beats. The team hypothesized that the visually driven response could be a series of preparatory movements to avoid the object. To test this, they filmed all-male flocks in the lab. Analyzing their movements, they found that males would move away when they approached other males.
“We think our findings suggest that males use close-range visual cues to avoid conflict within the flock,” Gupta says, “but their behavior appears to change dramatically when they hear the female’s flight sounds, suggesting the importance of integrating acoustic and visual information.”
A new trap that makes noise?
According to the teamThe study could demonstrate new mosquito control methods that target how mosquitoes integrate auditory and visual cues: when males hear the buzzing of a female, they are strongly and consistently attracted to the visual cue, which could be a weakness that researchers can exploit when designing new mosquito traps.
[Related: How can we control mosquitos? Deactivate their sperm.]
“Mosquito swarms are a popular target for mosquito control efforts because they result in a significant reduction in overall mosquito bites,” Riffel says, “but current measures such as insecticides are becoming less and less effective as mosquitoes develop resistance. New approaches, such as lures and traps that attract mosquitoes with high precision, are needed.”