Four new bee species - three of which have narrow heads and unusually long mouth parts - have just been discovered in Australia.
The bees, spotted during the nature discovery project called Bush Blitz, evolved their unique features to feed on a particular native plant.
"Three of the species belong to the group of bees that feed on the flowers of emu bushes," Katja Hogendoorn of the University of Adelaide explained in a press release. "The way they have adapted to be able to feed on these flowers is a great example of co-evolution."
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She continued: "These bees have narrow faces and very long mouth parts to collect the nectar through a narrow constriction at the base of the emu bush flowers. The fourth species belongs to a different group within this large genus and has a normally round-shaped head."
The genus, Euhesma, was determined based on evaluation of DNA "barcoding" and a detailed comparison of the bees with museum specimens.
The bees were found as the researchers explored Bon Bon Station Reserve, south of Coober Pedy in South Australia, and Cane River Conservation Park in the Pilbara region of Western Australia.
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Hogendoorn and colleagues believe that only two-thirds of Australian bee species are now known to science, so many more such discoveries are expected in future, if the bees do not become extinct beforehand.
"Habitat loss and pesticides are the main cause of native bee declines in Europe and the United States, but the conservation status of native Australian bees is largely unknown," Hogendoorn said.
"This lack of information," she added, "is largely because we have a very limited knowledge of the taxonomy, distribution and population dynamics of our invertebrates."
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"It would be a sad case if species became extinct before they were recognized."
The report on the new bees was published in the journal ZooKeys.