University of California - Santa Barbara (UCSB) researchers have discovered a way mosquitoes home in on humans for their blood feast — infrared (IR) from body heat. IR radiation combined with carbon dioxide from human exhalation and body odour, doubled their host-seeking capability. The mosquitoes navigated toward IR sources while homing in to humans. The finding provides a solution to avoid mosquito bites or significantly reduce chances of getting bitten by them, keeping mosquito-induced diseases like dengue, chikungunya, malaria, among others at bay.
The team studied female mosquitoes in a cage, measuring their host-seeking activity in two zones, each exposed to human odours and CO2 at the same concentration that we exhale. But one zone had IR from a source at skin temperature. They then counted how many mosquitoes began probing as if they were searching for a vein. Adding thermal IR from a 34º Celcius source doubled the insects’ host-seeking activity. The team documented IR as a newly discovered sense that mosquitoes use to locate humans up to 2.5 feet from the body. They found the IR-seeking ability came from the tips of their antennas which have heat-sensing neurons.
They found that the temperature-sensitive protein, TRPA1, at the end of the antenna helped them to detect IR. The team’s discovery allows improving methods for suppressing mosquito populations. Thermal IR from sources with temperatures equal to skin temperature could make mosquito traps more effective. The findings also explain why loose-fitting clothing is particularly good at preventing mosquito bites. It blocks mosquitoes from reaching our skin, and allows IR to dissipate between our skin and the clothing so the mosquitoes cannot detect it.
Science is a world in itself. Here are some interesting facts that connect with you
Nirad Mudur