Insect of the Year
Since the "Insect of the Year" board of trustees was established in 1999 – primarily by the then director of the German Entomological Institute, Prof. Dr. Holger Dathe – this commission selects each year an insect species that should enjoy greater fame because of its special importance for the ecosystem, its particular rarity, its aesthetic value or even its "ordinariness".
The Insect of the Year is intended to bring an exemplary species (and insects in general) closer to people. Well-known entomologists, representatives of research institutions and nature conservation organisations from Germany, Austria and Switzerland together make an important and difficult decision, the choice among about one million described insect species (even if "only" about 35,000 of them occur in Germany) and select the species that is to represent the inconspicuous and yet so important "creepy-crawlies" among humans for a whole year.
Insect of the year 2024: The Minotaur Beetle
The minotaur beetle (Typhaeus typhoeus), which is between 14 and 20 millimetres in size, is not a monster, even though it owes its scientific name to Typhon, a giant with a hundred dragon heads from Greek mythology. The German trivial name is more appropriate and refers to the three 'horns' of the male beetle in the front area of the neck shield, of which the two outer ones–as in the bull–are directed forwards. These horn-like extensions are used by the insects in fights with rivals and to protect their nesting sites. The coprophagous animals are extremely important for our ecosystems, as they ensure that the droppings of herbivorous animals are disposed of quickly and that no parasites can colonise them.
The minotaur beetle, which is widespread from North Africa to Western Europe and Eastern Central Europe, is the most powerful of its kind: The dung beetle species can pull more than 1,000 times its own body weight. The beetles use this strength to push faeces from rabbits, deer, cattle, sheep or horses in the form of a ball into the narrow passages of their breeding chambers as food for their offspring. After mating, bull beetles dig a shaft about one to two centimetres wide and up to 1.5 metres deep into the loose soil. The side passages each end in a chamber where the faeces are formed into a pill next to which the female lays the egg. The minotaur beetle larva hatches from the egg, crawls to the brood pill and feeds there. After about a year, the development of the beetles is complete.
Almost 10,000 species of coprophagous beetles are known worldwide, with around 130 species in Central Europe. Twelve of these–like the bull beetle–belong to the dung beetle family. Coprophagous beetles ensure that fresh faeces, especially from mammals, disappear from the soil surface relatively quickly–usually within a few days in our case. This closes the nutrient cycle in favour of plant growth. The beetles also regulate the development of parasitic worms and flies in mammal faeces, promote the transport of plant seeds and reduce the emission of greenhouse gases, particularly from cow dung. In the UK alone, the free services provided by faeces–eating beetles have been calculated at over 400 million euros per year. However, these ecosystem services are only provided if the faeces come from grazing livestock. Slurry and manure from livestock kept indoors cannot be utilised by the nocturnal beetles, which tend to live in hiding.
Since the mid-1980s, entomologists and ecologists have recorded a sharp decline in the populations of many dung beetles and dung beetles worldwide. The trigger: owners of grazing animals and other large livestock began to treat their animals with medication not only for acute diseases and parasite infestations. Anti-worm medication in particular is still regularly administered prophylactically worldwide. As the active ingredients are excreted by the treated animals, they have an effect beyond the actual target organisms–with consequences for all insects living in or feeding on the faeces. As a result, coprophagous beetles die or reproduce only to a limited extent.
Dung beetles and dung beetles are among the most endangered groups of insects. The decline in beetles is categorised by scientists as a significant part of the dramatic global loss of insect fauna. In Central Europe, several measures are required to maintain or restore a near-natural and effective coprophagous fauna. These include reducing the use of antiparasitic drugs in pets and livestock–above all, these drugs should no longer be administered purely prophylactically. Farm animals should also be allowed to graze again wherever possible. Keeping animals indoors must be the exception, not the rule. Let's hope that the minotaur beetle becomes a good ambassador for the important role of faecal beetles.