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The World’s Deepest Flying Insect Lives in Complete Darkness with No Food or Sex

Troglocladius hajdi, a blind non-biting midge that lives underground. Photo by Martina Pavlek.

Deep below the Velebit mountains of Southern Croatia, 1,431 meters under ground, lies the Lukina Jama cave system, the 14th deepest cave in the world.

In the last decade, this cave has received much attention by cave scientists for its comparatively rich fauna of strictly subterranean animals, including subterranean leeches and a translucent snail species that does not occur anywhere else in the world. The most recent addition to the list is a small insect that has the distinction to be the world’s only blind cave insect that flies.

In a recent article published in the journal PLOS ONE, a team of scientists from Norway, Germany, and Croatia described and named a new species of non-biting midge that is new to science. The scientific name Troglocladius hajdi refers to both its subterranean habits and the local folklore from its area of origin. Troglocladius loosely translates as “cave midge,” and hajdi refers to a race of winged, underground fairies from Slavic mythology.

Its many cave-associated features include a nearly complete lack of eyes, elongated legs for feeling its way around, and the lack of pigment in the body. However, unlike all other known strictly subterranean insects, it has retained large wings that appear to be functional.

Specimens of the new species were first found in 2010, and took a long time to describe because of the insect’s curious adaptation to cave life.

Non-biting midges are in general very difficult to work with, and it is often necessary to examine both male genitalia and DNA sequences to even identify the species. In the case of Troglocladius hajdi, the situation was particularly difficult because only female specimens have been found, and the researchers who described it suggest that this is because the species has no males and only reproduces asexually. The DNA studies confirm these sexless, blind flyers as evolutionarily distinct from all other known non-biting midges that have undergone DNA sequencing.

Exactly what the tiny insect does in the cave, besides flying, is still unclear. The researchers found no larvae or pupae, but suggested that these probably either dwell in small vertical streams on the cave walls or in underground ponds. The adults probably do not feed at all. Further expeditions to the cave are currently being planned in order to learn about the larvae and to get material for more detailed DNA studies.

Read more at:

Blind Flight? A New Troglobiotic Orthoclad (Diptera, Chironomidae) from the Lukina Jama – Trojama Cave in Croatia

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