The oldest mosquito fossil comes with a bloodsucking surprise. Each year, malaria and other diseases that are transmitted through the bite of mosquitoes, which are insects that date back to the time of dinosaurs, are responsible for the deaths of hundreds of thousands of people all over the world. Females, who have a more specialized oral structure than their male counterparts, carry out each of these bites.
Nevertheless, things have not always been like that. The two male insects found in fragments of amber going back to 130 million years ago during the Cretaceous Period, located close to the town of Hammana in Lebanon, were the earliest known fossils of mosquitoes, according to the researchers who made the discovery. They were taken aback when they discovered that male mosquitoes had extended, piercing-sucking mouthparts, which are today exclusively found in female mosquitoes.
“Clearly they were hematophagous,” which means they consumed blood, said geologist Dany Azar of the Nanjing Institute of Geology and Paleontology at the Chinese Academy of Sciences and Lebanese University. Azar was the study’s primary author, published in the journal Current Biology this week. “So this discovery is a major one in the evolutionary history of mosquitoes.”
The two fossilized insects, representing the same ancient species, are comparable to current mosquitoes in size and appearance. However, the mouthparts that are used for acquiring blood are shorter than those that are used by female mosquitoes in the present day.
“Mosquitoes are the most notorious blood-feeders on humans and most terrestrial vertebrates, and they transmit a certain number of parasites and diseases to their hosts,” according to Azar.
Because they require proteins to generate their eggs, only female mosquitoes fertilized will consume blood. Nectar from plants that have not yet been fertilized is consumed by men and females. A few of the men, Azar said, do not consume any food at all.
Some flying insects, such as tsetse flies, have males that consume blood instead of blood. However, contemporary mosquitoes are not the same.
According to André Nel, a paleontologist and co-author of the study at the National Museum of Natural History in Paris, “Finding this behavior in the Cretaceous is quite surprising.”
The two insects’ delicate anatomy was exquisitely preserved in the fossils found in the rainforest. In addition to having an extended structure with tooth-like projections, both had jaw architecture that was extraordinarily sharp and formed like a triangle.
According to the experts, they strongly suspect mosquitoes originated from insects that did not feed on their blood. They postulate that the mouthparts that eventually evolved into those utilized for collecting blood meals were initially employed for piercing plants to gain access to nutrient-rich fluids.
The disparity in eating habits between male and female mosquitoes might be attributed to developments in plant evolution. When these two insects were entangled in tree sap that would later turn into amber, blooming plants were beginning to grow for the first time in the landscape of the Cretaceous period.
“In all hematophagous insects, we believe that hematophagy was a shift from plant liquid sucking to bloodsucking,” according to Azar.
In addition, Azar stated that the fact that these earliest-known mosquitoes are males that feed on blood indicates that the first mosquitoes were all hematophagous, regardless of whether they were males or females. However, hematophagy was later lost in males, possibly due to the appearance of flowering plants, which occurred at the same time as the formation of Lebanese amber.
Many creatures, including dinosaurs, flying reptiles known as pterosaurs, other reptiles, birds, and mammals, appeared to be present to offer blood feasts.
Even though these fossils are the oldest known, the experts indicated mosquitoes most likely began millions of years earlier. During the Jurassic Period, which lasted from around 200 million to 145 million years ago, they observed that molecular evidence implies that mosquitoes originated during that time.
Except in Antarctica, over a thousand five hundred different kinds of mosquitoes may be found globally. Malaria, yellow fever, Zika fever, dengue fever, and other illnesses can be transmitted by some individuals who evolve into disease vectors. Malaria, a parasite illness, is responsible for the deaths of more than 400,000 people every year, the majority of whom are children under the age of five, as stated by the World Health Organization.
“On the other side, mosquitoes help to purify the water in ponds, lakes and rivers,” according to Nel. “In general, an animal can be a problem but also can be helpful.”
