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| Libanoculex intermedius Azar, Nel, Huang & Engel, 2023 |
Highlights:
• Earliest-diverging lineage and oldest occurrence of mosquitoes
• Male mosquito with well-developed, denticulate, and hematophagous-type mouthparts
• New extinct subfamily of mosquitoes
Summary:
Female mosquitoes are among the most notorious blood-feeding insects, sometimes causing severe allergic responses or vectoring a variety of microbial pathogens. Hematophagy in insects is likely a feeding shift from plant fluids, with the piercing-sucking mouthparts serving as suitable exaptation for piercing vertebrates’ skin. The origins of these habits are mired in an often-poor fossil record for many hematophagous lineages, particularly those of sufficient age, as to give insights into the paleoecological context in which blood feeding first appeared or even to arrive at gross estimates as to when such shifts have occurred. This is certainly the case for mosquitoes, a clade estimated molecularly to date back to the Jurassic. The known Mesozoic Culicidae are Late Cretaceous, assigned to the modern Anophelinae or to the extinct Burmaculicinae, sister to other Culicidae, all with mouthparts of a modern type. Here, we report the discovery, in Lower Cretaceous amber from Lebanon, of two conspecific male mosquitoes unexpectedly with piercing mouthparts, armed with denticulate sharp mandibles and laciniae. These male fossils were likely hematophagous. They represent a lineage that diverged earlier than Burmaculicinae, extending the definitive occurrence of the family into the Early Cretaceous and serving to narrow the ghost-lineage gap for mosquitoes.
Keywords: Culicidae, Lower Cretaceous, Lebanese amber, male hematophagy, new family, developed mouthparts
Systematic paleontology
Order Diptera Linnaeus, 1758
Family Culicidae Billberg, 1820
Libanoculicinae subfam. nov.
Libanoculex gen. nov.
Etymology: The generic name is a combination of the Latin Libanus, meaning “Lebanon,” and the generic name Culex L. (Latin, meaning “gnat” or “mosquito”). Gender of the name is masculine.
Libanoculex intermedius sp. nov.
Etymology: The specific epithet is the Latin adjective intermedius, meaning “intermediate” or “between,” and refers to the early diverging position of the fossil relative to other Culicidae and its unique combination of culicid apomorphies and symplesiomorphies with Chaoboridae.
Outcrop and horizon: Mdeirij-Hammana outcrop, Caza (= District) Baabda, Central Lebanon, lower Barremian.
Dany Azar, André Nel, Diying Huang and Michael S. Engel. 2023. The Earliest Fossil Mosquito. Current Biology. DOI: 10.1016/j.cub.2023.10.047
https://phys.org/news/2023-12-earliest-known-fossil-mosquito-males-bloodsuckers.html
