Researchers at the University of California, Riverside, have discovered that volatile repellents might be used to control insects on surfaces such as windowsills, eaves of huts, home entryways, backyards, outside food storage spaces, entryways of animal shelters, and adjacent to crops in a field.
Mosquitoes transmit various illnesses, including malaria and dengue. In 2020, around 241 million cases of malaria were reported globally, with a few million additional cases reported in 2021.
Almost half of the world's population lives in areas where the dengue virus is a concern. Insects also annihilate one-third of farmland.
Studies identify new strategies for insect control
The researchers concentrated on ammonia, a common volatile chemical found in insect habitats.
Ammonia attracts mosquitoes and other insects in low amounts, such as in human perspiration, as per ScienceDaily.
However, at high amounts, such as those found in household cleaners, ammonia is no longer appealing to insects.
The researchers wanted to know what happens to the olfactory (smell) and gustatory (taste) systems of fruit flies and mosquitos when they are exposed to ammonia.
"We discovered that the olfactory neurons have a burst of activity and then go silent for a time," said Anandasankar Ray, a professor of molecular, cell, and systems biology who led the study, which was published in the journal iScience.
Most insects use their taste system after locating a suitable landing site using their scent system.
Mosquitoes taste food via the labella, which are sensory probes on their legs that help them find a good area to bite. Fine hairs on the labella of fruit flies, known as sensilla, allow the flies to taste possible meals without swallowing them.
Ray believes that the discovery might be exploited to develop effective insect repellents in the future. While substances with a high pH that is basic cannot be utilized on the skin due to their corrosive qualities, he claims they can be employed in other ways.
Many biting insects enter dwellings from the outside. In most regions of the world, insects attack people and dogs indoors, especially at night.
Mosquitoes, for example, would be harmed if the walls where insects settle and wait included a high pH substance.
Similarly, if a high pH substance, such as an amine, was sprayed around the entrances to dwellings and livestock shelters, it may deter mosquitoes.
Read more: Mosquito Swarm Strikes Farmer's Home After Heavy Rainfall Events in Australia [Video]
It's due to the humidity
Ray's group explored humidity-induced behavior alteration in the Asian citrus psyllid, or ACP, which transmits citrus greening disease, and mosquitoes in a separate research published in the journal Scientific Reports.
Although insects can detect humidity, there has been minimal investigation into altering their humidity-sensing neurons, as per Phys.org.
The researchers subsequently investigated humidity sensing in gravid mosquitos (Aedes aegypti and Anopheles coluzzi), which are drawn to bodies of water to lay eggs. Blood-fed mosquitos that were ready to lay eggs were given two cups of water in the lab.
One cup included a little vial of odor that prevented humidity detection. The mosquitoes avoided depositing eggs in the untreated cup, according to the researchers.
He also stated that ACPs appear to avoid high humidity levels. His lab employed a Y-shaped tube with high humidity in both arms to test their humidity sensitivity. Initially, neither arm was chosen by the ACPs.
However, when the researchers applied a humidity-inhibiting odorant to one arm, the ACPs began to prefer it since they could no longer detect the dampness.
"This implies that by employing a volatile odorant to limit the insects' capacity to smell water, we may influence their humidity sensing route and affect their behavior predictably," Ray explained.
It may be conceivable in the future to create amines to inhibit insect egg-laying in certain regions.
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