Why Male Mosquitoes Once Sucked Blood but Have Now Become Vegetarians? 0 10

A group of scientists from the Nanjing Institute of Geology and Palaeontology of the Chinese Academy of Sciences and the Lebanese University made an important discovery by finding the earliest known fossil mosquitoes in Lower Cretaceous amber, which is about 100 million years old. These well-preserved insects consist of two males of the same species with a piercing mouthpart, suggesting that they may have sucked blood.

“Lebanese amber is the oldest amber with rich biological content. It is an extremely important material, as its formation coincides with the emergence and spread of flowering plants, which has significant implications for the co-evolution of pollinators and flowering plants,” notes co-author of the study Deni Azar.

The family of mosquitoes, Culicidae, includes over 3,000 different species. According to the researchers, new data suggest that in the past, male mosquitoes may also have fed on blood.

Female mosquitoes are blood-sucking insects, which have made them major carriers of infectious diseases. It is believed that hematophagy in insects arose from an evolutionary transition from a piercing-sucking mouthpart that was used to extract plant juices. For example, blood-sucking fleas likely evolved from nectar-feeding insects. However, studying the evolution of blood-feeding presents a complex challenge, partly due to the lack of data in the fossil record of insects.

In the new study, scientists describe two male mosquitoes with a piercing mouthpart that had a sharp triangular lower jaw with fine teeth.

The researchers report that the preservation of mosquitoes in amber indicates an earlier distribution of the mosquito family dating back to the early Cretaceous period. This also suggests that the evolution of hematophagy was more complex than previously thought, as there were males in the distant past that may have fed on blood.

The reasons why only blood-sucking females remain today are still unexplained by scientists.