31.01.2018 change 31.01.2018

A curious shiny blue moth species rediscovered after 130 years

Heterosphecia tawonoides. Photo by Marta Skowron-Volponi Heterosphecia tawonoides. Photo by Marta Skowron-Volponi

It is an oriental blue moth, but its appearance, behaviour and sounds mimic blue bees found in Malaysia. 130 years after its last observation, the oriental blue clearwing (Heterosphecia tawonoides) was spotted by a doctoral student from the University of Gdańsk.

Heterosphecia tawonoides belongs to the clearwing moths family. Its appearance, behaviour, as well as the sounds it makes mimic blue bees found in Malaysia. The only previously known individual of the species was discovered 130 years ago - and the moth has not been seen since.

Marta Skowron Volponi, a PhD student at the Faculty of Biology of the University of Gdańsk, recently spotted this species - reports the university's spokesperson in a release. The researcher described her find in Tropical Conservation Science.

"This moth has a mere two-centimetre wingspan, but it hides so many fascinating things that we have already discovered, and we still hope to discover more" - says Marta Skowron Volponi, vice president of the ClearWing Foundation for Biodiversity.

The biologist from the University of Gdańsk notes that the name of the family (clearwing moths) is quite descriptive, as the moths in this family have transparent wings. "But the term +moth+ is inaccurate and misleading. When thinking about moths, people imagine grey, hairy insects attracted by light. This species is strikingly different: beautiful, with a blue gloss in the sunlight, active during the day, and a master of mimicry. It mimics bees on many levels, and even stays among them in their natural environment" - she says.

In terms of appearance, clearwing moths resemble wasps or bees. They have similar narrow, clear wings and bright stripes on the abdomen. These insects often also have "hairy" legs, but in the case of the H.tawonoides species, these are actually elongated scales, which have evolved to make the moths resemble bees even more. "Such adaptations make a predator think twice before attempting an attack on an insect that might pack a sting" - says Marta Skowron Volponi.

The rediscovered Heterosphecia tawonoides was previously known only as a single, damaged museum specimen collected in 1887 in Sumatra. It is currently in the collection of the Museum of Natural History in Vienna. This specimen is a holotype, based on which Dr. Axel Kallies described it as a new species only in 2003.

In their article, Marta Skowron Volponi and the second author of the publication, Paolo Volponi (nature filmmaker, president of the ClearWing Foundation, and privately the researcher's husband) for the first time described the behaviour of this species.

H.tawonoides can be found in tropical forests, among bees and wasps, where they fly along the river banks in search of naturally occurring salt. If the moth finds the right spot, then - using a long mouthpart, typical for butterflies - it drinks salt solution from the moist substrate. This behaviour is only exhibited by males of the species. They probably pass the sodium on to females in a copulation act, but this has not been verified for this species.

Marta Skowron Volponi observed clearwings flying in a zigzag pattern, just like bees. She also heard and recorded their buzz. A video showing a buzzing moth is available here: https://vimeo.com/229602724

H.tawonoides seems to be associated with a specific environment: the banks of clean rivers flowing through the original rainforest of Malaysia, home to Indian elephants, gibbons and Malay bears. Malaysia is one of the most biodiverse places on Earth, but it is also among the countries with the highest degree of deforestation in the world. Although the main place of occurrence of the moth is the Taman Negara national park, Marta Skowron, Volponi has found this species also outside the protected area, on the other side of the river, where the forests are intensively being cut.

In addition the rediscovery of Heterosphecia tawonoides, Marta Skowron Volponi has recently discovered three new species of clearwings: the bee-like Heterosphecia pahangensis - a species that even has yellow imitations of pollen on its hind legs; the narrow, wasp-like Pyilslepella ellawi with extremely fast flight, and Aschistophleps argentifasciata from Thailand, whose name comes from the silver band on the abdomen (follow the links for details about the species).

More information about the butterfly is available in the article Fri "A 130-Year-Old Specimen Brought Back to Life: A Lost Species of Bee-Mimicking Clearwing Moth, Heterosphecia tawonoides (Lepidoptera: Sesiidae: Osminiini), Rediscovered in Peninsular Malaysia's Primary Rainforest".

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