Tuesday 16 October 2018

Dung Beetles

For the general public I have no doubt that the idea of investigating dung for its insect life is rather repellent. The 'Cow-dung Community' (Ref.1) is in fact endlessly fascinating and, of course, is of vital importance for agriculture and the general well-being of our countryside. In Australia the introduction of sheep and cattle created a problem, for no dung community existed there and significant areas of land gradually became less productive as a result of ungraded dung, because of course vital soil nutrients were locked up in this material. Great efforts have been made over the last few decades to establish a bucoprophilous fauna to deal with the  situation.
The dung of carnivorous animals is often unpleasant both in terms of odour and its potential for spreading disease via insects. With herbivorous animals these problems are not entirely absent and sensible hygiene precautions need to be taken but Eau de Sheep Poo is usually very faint and the insect visitors are, in general, very unlikely to go on to visit our picnic table. Of course, when I say the odour is very faint, that is not the case for insects such as dung beetles. Often the dung has barely hit the ground before the beetles arrive and, once there, they virtually 'swim' into this rich food source. Significantly several dung beetles belong to the mainly aquatic Hydrophilidae 'water-loving' family.
Many dung beetles are quite small, tiny even, but the rather handsome Aphodius fimetarius females can reach 8 mm in length.



Aphodius fimetarius, taken in flight. Foxhill Farm, Badby.
31 May, 2018
The most interesting of the dung beetles taken so far this year has been Onthophagus  coenobita. I retrieved it, more dead than alive, from a water trough on Foxhill Farm. Its elytra (forewings) have the same red-brown coloration (dung coloured?) as Aphodius fimetarius, but is far less common and this may be the first recording of it from Northants.

My pinned specimen (9 mm) of Onthophagus coenobita from Foxhill Farm, Badby. 9 September, 2018
It may now be approaching mid-October but there are still plenty of dung beetles around. Aphodius contaminatus is particularly common and I have even found one or two on window ledges around the house, but we are only three hundred yards from the nearest sheep pasture.


Thought. In mediaeval times dung was often incorporated into daub for the construction of walls. I wonder whether dung beetles have been found entombed in this mixture? I will investigate.


Reference


Skidmore, Peter (1991) Insects of the Cow-dung Community. Field Studies Council.
This book should be in every home. It is the perfect antidote to 'Strictly Come Dancing'.





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