Study claims male mosquitoes used to suck blood in past but they ‘evolved’

Years of investigation have established that exclusively female mosquitoes partake in blood-feeding, as opposed to male mosquitoes, which lack the mouthparts utilized by females to penetrate the skin.

However, in a study published on December 4, researchers examining one of the earliest-known mosquito fossils from Lower Cretaceous amber in Lebanon assert that male mosquitoes may have engaged in blood-sucking in the past.

Lebanese amber, renowned for its well-preserved fossils or inclusions, dates back to approximately 125 million years in the early Cretaceous period, as reported by the New York Times.

The discovery unfolded as Dany Azar, a palaeontologist at the Nanjing Institute of Geology and Palaeontology and Lebanese University, and the lead author of the paper, scrutinized a thin amber slice containing the fossil under a microscope. To his astonishment, he identified a mosquito. Azar remarked, “To my big surprise, I said, ‘Oh, gosh, this is a mosquito.’”

Further investigation revealed that the mosquito possessed claspers on its abdomen, leading Azar to contemplate an unprecedented possibility: male mosquitoes might have engaged in blood-sucking in the past. Azar expressed, “We think now that, originally, the mosquito could be bloodsucking. With the appearance of the flowering plant, this function could be just forgotten later on during the evolution of these insects.”

The question of why male mosquitoes relinquished blood-sucking was addressed. Typically, mosquitoes, being riskier, refrain from blood-sucking, a strategy associated with feeding on a living organism. In the present context, only female mosquitoes undertake this activity, primarily for additional energy required for reproduction. The evolution of male mosquitoes led them to abandon blood-sucking, as they don’t need to produce eggs and can sustain themselves by consuming nectar and plant juices.

While the discovery is captivating, the study acknowledges limitations, acknowledging the possibility that the fossil in question might ultimately be something other than a mosquito.