South African dung beetles, new research


This 2007 video says about itself:

African Dung Beetle | National Geographic

Sacred to ancient Egyptians, these beetles recycle – of all things – dung.

From the University of Würzburg in Germany:

How dung beetles know where to roll their dung balls

June 25, 2019

Summary: When the South African dung beetle rolls its dung ball through the savannah, it must know the way as precisely as possible. Scientists have now discovered that it does not orient itself solely on the position of the sun.

The South African dung beetle Scarabaeus lamarcki has — to put it mildly — an interesting technique to ensure its offspring a good start in life. When the animal, which is only a few centimetres tall, encounters elephant dung, for example, it forms small balls out of it which it then rolls away in a randomly chosen direction. After a while, the beetle stuffs the dung into underground passages, which serve as its breeding chamber; where it then lays its eggs.

How the dung beetle finds its way from the elephant dung pile to the underground passages: This is what Dr. Basil el Jundi is interested in. The neurobiologist heads an Emmy Noether Junior Research Group at the Biocentre of Julius-Maximilians-Universität Würzburg (JMU) in Bavaria, Germany, and investigates the navigational ability of insects.

Together with scientists from Sweden and South Africa, he has now discovered that the dung beetle — contrary to previous assumptions — does not only orient itself on the position of the sun when navigating, but also includes information about wind direction in its route planning. The researchers have published their new findings in the current issue of the journal PNAS — Proceedings of the National Academy of Sciences.

On a straight line away from the dung heap

“South African dung beetles must roll their dung ball away from the dung pile as quickly as possible to prevent the ball from being stolen by other beetles,” explains el Jundi. To ensure that they actually get out of the dangerous area as quickly as possible, the beetles roll the ball away from the dung pile along a straight line. In order to keep their course, they use celestial cues as orientation references — for example, the position of the sun. However, it was not yet clear how the beetles find their way when the sun provides no useful information, for example when it is noon.

Basil el Jundi and his team can now answer this question: “We have discovered that dung beetles use the wind for orientation in addition to the sky.” The animals perceive the corresponding signals via their antennae. The necessary information is provided by high wind speeds, which occur in the African savannah especially around noon, when orientation by the sun becomes difficult.

The combination of the systems increases precision

However, to produce an efficient and robust “compass”, the animals must combine and harmonize the wind information with the other celestial signals. This is the only way to ensure that they find their way, even in a sudden calm, by flexibly switching back to the solar compass as the main orientation signal. As the researchers were able to show, this combination of different orientation systems not only makes it easier for the beetle to find its way, but it also increases the precision of the beetle compass.

For their study, the scientists worked within a laboratory arena in which they were able to simulate and control the position of the sun and the wind direction to precisely record their effects on beetle navigation. Their experiments not only show that the beetles set the wind directional information relative to the position of the sun. “We could also show that the beetles were able to transfer the directional information, which they have set with the sun as their only reference, to the wind compass,” says el Jundi. This shows that both the wind compass and the solar compass in the beetle brain “access” the same spatial memory network and therefore communicate with each other.

A highly plastic neuronal machinery

Thus, the recently published study shows that dung beetles use a much more dynamic compass than science has previously thought possible. The access to different sensory modalities enables the animals to navigate at any time with highest precision. Their abilities clearly exceed human abilities — even though they are equipped with a brain that is smaller than a grain of rice. In addition, the results confirm that an insect brain is not a “static substrate”, but a piece of a “highly plastic neuronal machinery that can adapt to its environment in a perfect way”, as the scientists write.

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103 new beetle species discovered in Indonesia


This 29 May 2016 video in German with English subtitles is about very big Dorcus titanus, aka giant stag beetles, from Sulawesi island in Indonesia. This male is 94 millimeter.

Now, to much smaller beetles from Sulawesi.

From ScienceDaily:

Star Wars and Asterix characters amongst 103 beetles new to science from Sulawesi, Indonesia

March 7, 2019

Summary: A total of 103 new species of weevils are added to the genus Trigonopterus from Sulawesi. Whereas prior to the study, there had only been a single species from this group documented on the Indonesian island. Having remained undercover due to their tiny size (2-3 mm) and close superficial resemblance, a team of scientists managed to identify the novel species thanks to modern DNA analyses.

The Indonesian island of Sulawesi has been long known for its enigmatic fauna, including the deer-pig (babirusa) and the midget buffalo. However, small insects inhabiting the tropical forests have remained largely unexplored.

Such is the case for the tiny weevils of the genus Trigonopterus of which only a single species had been known from the island since 1885. Nevertheless, a recent study conducted by a team of German and Indonesian scientists resulted in the discovery of a total of 103 new to science species, all identified as Trigonopterus. The beetles are described in the open-access journal ZooKeys.

“We had found hundreds of species on the neighboring islands of New Guinea, Borneo and Java — why should Sulawesi with its lush habitats remain an empty space?” asked entomologist and lead author of the study Dr Alexander Riedel, Natural History Museum Karlsruhe (Germany).

In fact, Riedel knew better. Back in 1990, during a survey of the fauna living on rainforest foliage in Central Sulawesi, he encountered the first specimens that would become the subject of the present study. Over the next years, a series of additional fieldwork, carried out in collaboration with the Indonesian Institute of Sciences (LIPI), managed to successfully complete the picture.

“Our survey is not yet complete and possibly we have just scratched the surface. Sulawesi is geologically complex and many areas have never been searched for these small beetles,” said Raden Pramesa Narakusumo, curator of beetles at the Museum Zoologicum Bogoriense (MZB), Indonesian Research Center for Biology.

Why have all these beetles remained overlooked for so long?

Unlike the all-time favourite stag beetles or jewel beetles, tiny beetles that measure no more than 2-3 millimeters seem to have been attracting little interest from entomologists. Their superficial resemblance does not help identification either.

In fact, the modern taxonomic approach of DNA sequencing seems to be the only efficient method to diagnose these beetles. However, the capacity for this kind of work in Indonesia is very limited. While substantial evidence points to thousands of undescribed species roaming the forests in the region, there is only one full-time position for a beetle researcher at the only Indonesian Zoological Museum near Jakarta. Therefore, international collaboration is crucial.

103 beetle names

Coming up with as many as 103 novel names for the newly described species was not a particularly easy task for the researchers either. While some of the weevils were best associated with their localities or characteristic morphology, others received quite curious names.

A small greenish and forest-dwelling species was aptly named after the Star Wars character Yoda, while a group of three species were named after Asterix, Obelix and Idefix — the main characters in the French comics series The Adventures of Asterix. Naturally, Trigonopterus obelix is larger and more roundish than his two ‘friends’.

Other curious names include T. artemis and T. satyrus, named after two Greek mythological characters: Artemis, the goddess of hunting and nature and Satyr, a male nature spirit inhabiting remote localities.

Additionally, the names of four of the newly described beetles pay tribute to renowned biologists, including Charles Darwin (father of the Theory of Evolution), Paul D. N. Hebert (implementer of DNA barcoding as a tool in species identification) and Francis H. C. Crick and James D. Watson (discoverers of the structure of DNA).

Six-legged déjà vu

Back in 2016, in another weevil discovery, Dr Alexander Riedel and colleagues described four new species from New Britain (Papua New Guinea), which were also placed in the genus Trigonopterus. Similarly, no weevils of the group had been known from the island prior to that study. Interestingly, one of the novel species was given the name of Star Wars’ Chewbacca in reference to the insect’s characteristically dense scales reminiscent of Chewie’s hairiness. Again, T. chewbacca and its three relatives were described in ZooKeys.

On the origin of Trigonopterus weevils

Sulawesi is at the heart of Wallacea, a biogeographic transition zone between the Australian and Asian regions. The researchers assume that Trigonopterus weevils originated in Australia and New Guinea and later reached Sulawesi. In fact, it was found that only a few populations would one day diversify into more than a hundred species. A more detailed study on the rapid evolution of Sulawesi Trigonopterus is currently in preparation.

Future research

To help future taxonomists in their work, in addition to their monograph paper in ZooKeys, the authors have uploaded high-resolution photographs of each species along with a short scientific description to the website Species ID.

“This provides a face to the species name, and this is an important prerequisite for future studies on their evolution,” explained the researchers.

“Studies investigating such evolutionary processes depend on names and clear diagnoses of the species. These are now available, at least for the fauna of Sulawesi.”

African dung beetle rolls big ball


This 20 February 2019 video from South Africa says about itself:

Dung Beetle Rolls Enormous Dung Ball with Difficulty (4K)

The Addo flightless dung beetle isn’t one to give up – even when the ball of dung he’s pushing is easily 20 times his size. He’ll roll it all the way home for as long as it takes.

How click beetles move, new study


This 2013 video from the USA says about itself:

Eyed click beetle (Alaus oculatus) – This beetle belongs in the circus

My friend Bill and I were out looking for invertebrates and we found this guy under a log. It is a very large click beetle. The time of year is mid May. This is shot with my brand new sony cybershot DSC-wx150 so I finally got to try some test footage shooting in MP4.

From the University of Illinois College of Engineering in the USA:

Hinge morphology of click beetles‘ latch mechanism

February 18, 2019

Aimy Wissa, assistant professor of mechanical science and engineering (MechSE) at Illinois, leads an interdisciplinary research team to study click beetles to inspire more agile robots. The team, which includes MechSE Assistant Professor Alison Dunn and Dr. Marianne Alleyne, a research scientist in the Department of Entomology, recently presented their ongoing and novel work on the quick release mechanism of click beetles at the 2019 Society for Integrative and Comparative Biology (SICB) Annual Meeting.

Ophelia Bolmin, a graduate student in Wissa’s Bio-inspired Adaptive Morphology (BAM) Lab, presented novel synchrotron X-ray footage that showed the internal latch mechanism of the click beetle, and demonstrated for the first time to the scientific community how the hinge morphology and mechanics enable this unique clicking mechanism. The presentation, “The click beetle latch mechanism: An in-vivo study using synchrotron X-rays,” was part of an invited symposium on mechanisms of energy flow in organismal movement.

This work builds on research that was initiated by the Illinois team nearly two years ago, detailing the click beetles’ legless self-righting jumping mechanism. The team already built prototypes of a hinge-like spring-loaded device that are being incorporated into a robot.

Rather minimal research had been performed on the click beetle’s click mechanism in the past, and the Illinois team is the first to explore the insect within the field of bio-inspiration — using inspiration from nature for innovative engineered designs. They continue to be at the forefront of this research, and further studies are scheduled to be published in coming months.

Dung beetles fight about dung, video


This 25 January 2019 video says about itself:

Dung Beetles Battle for a Ball of Poop | National Geographic Wild

There can only be one winner in this fight for a smelly prize.

Of all nocturnal animals, only dung beetles can hold their course using polarized moonlight. Researchers at Lund University in Sweden have now shown that the beetles can use polarized light when its signal strength is weak,which may allow them to find their bearings when artificial light from cities swamp natural moonlight: here.