dung beetles – Page 2 – More Than A Dodo

Why the world needs Dung Beetles

To celebrate National Insect Week 2016 we thought we would introduce you to the custodians of the Hope Entomology Collection here at the Museum. Our insect collection is made up of a whopping 6 million specimens, so our resident entomologists definitely have their work cut out. However, they have taken a little time out to tell us all about their specialisms and why their favourite insects are the best.

Darren Mann – Head of Life Collections

Darren out in the field collecting Dung Beetles

Dung beetles have been my passion since my late teens. I started with British species and then gradually broadened my interests to encompass the world fauna. But why dung beetles?

Well, they are beautiful insects, exhibiting an array of shapes and colours; they have been around since the dinosaurs, and have interesting biologies and behaviours, from nest-building and parental care, to stargazing. As a group, dung beetles are also very important in the ecosystem, removing dung and recycling nutrients.

Not only that, but dung removal and relocation offers additional ‘ecosystem services’ of fly control, livestock parasite suppression, plant growth enhancement, improved soil structure, reduction of greenhouse gas emissions, seed dispersal, and pollination. Inevitably, they are a source of food for other animals too.

Darren takes a closer look at a collected specimen

Dung beetles are found in all regions of the world, and consist of three main groups: the dor or earth-boring beetles (Family Geotrupidae) of around 600 species; the ‘lesser’ dung beetles (Family Scarabaeidae, subfamily Aphodiinae) of around 3,500 species; and the ‘true’ dung beetles (Family Scarabaeidae, Subfamily Scarabaeinae) of around 6,000 species.

With just over 10,000 species in total you’d think we have found all the dung beetles out there, but not so: it’s estimated that 40 per cent of species new to science are still to be discovered. In the UK we have just 60 species and over half of these are in decline due to agricultural intensification, pollution, use of veterinary drugs, and changes in livestock farming practises. The Dung Beetle Mapping UK Project (DUMP) aims to highlight the importance of this group and promote research and conservation in this area.

Despite their name, not all dung beetles eat dung, with some species preferring fallen fruit, fungi, or even dead animals. The South American roller (Deltochilum valgum) is an avid predator of millipedes and another South American species (Zonocopris gibbicollis) feeds on snail mucus!

So with their high diversity, fascinating ecology, and great economic benefit, perhaps the question really should be ‘why not study dung beetles?’.

Nature’s Waste Management Team

A Spotlight Specimens special for Oxford Festival of Nature

By Darren Mann, Head of Life Collections

One cow can produce over nine tonnes of dung per year. With a population of about 3.4 million cows in the UK alone, that’s a heck of a lot of dung deposited on our grasslands. Just imagine how much dung is produced every year if we include the output of horses, sheep, pigs, and all the wild animals out there.

Dor Beetle – Geotrupes mutator

All of this dung is broken down by a multitude of invertebrates, including flies, worms, and beetles, as well as bacteria, fungi, and weathering. One of the key groups involved in the removal and degradation process is the aptly named ‘dung beetles’.

In the UK there are 61 species of dung beetle, though sadly just over half of these are now in decline and some have already become regionally extinct. UK dung beetles vary in size from just 3 mm to over 25 mm and occur wherever dung is found, though some prefer sandy soils and others like to live in woodlands.

Dung beetle larvae (Aphodius fossor)

As adults, dung beetles feed on the liquid part of dung. The larvae of most of our species live inside the dung pile and are called the dwellers. These munch their way through the solid matter of the dung pile, gradually breaking it down over a few months. Other species such as Geotrupes mutator, pictured above, excavate a tunnel and bury the dung below ground. These tunnellers construct a brood chamber in which their young develop.

Aphodius fossor

Through their actions, dung beetles perform a number of valuable ecosystem services. The most obvious is dung removal and degradation which leads to improved soil health by nutrient cycling and soil movement. By burying the dung they reduce the amount of available breeding habitat for pest flies and livestock parasites too.

All of these important services have been estimated to save the UK cattle industry £367 million per year. The value of dung beetles doesn’t end there as they also provide an important source of food for farmland mammals and birds. So next time you see a pile of dung in a field, just think of all the hard working beetles within…

Staff and associates of the Museum also run the Dung beetle UK Mapping Project – affectionately abbreviated to DUMP!