Dung beetles: Masters of plant nutrient recycling are harmed by exposure to agricultural chemicals.
Dung beetles are a vital component of biological farming in that they facilitate the recycling of plant nutrients held in animal dung.
Up to 80% of the nitrogen held in dung volatilizes when cow pats are left on the ground for any length of time. Dung beetles bury the dung quickly and enable most of the nitrogen to be sequestered and available to plants. Watch dung beetles in action here. http://www.youtube.com/watch?v=I1RHmSm36aE
Agricultural chemicals harm dung beetles!
The research below shows that picloram, the active ingredient in the herbicide Tordon 101M, is harmful to dung beetles. Picloram is also the active ingredient in Tordon 50D and the brush weed herbicide Conquest.
Martinez, I. M., J. P. Lumaret, et al. (2001). "Suspected side effects of a herbicide on dung beetle populations (Coleoptera: Scarabaeidae)." Comptes Rendus de l'Academie des Sciences. Serie III, Sciences de la Vie 324(11): 989-994.
This paper addresses the association between the use of the herbicide Tordon 101M [picloram] and anecdotal reports on reduced dung degradation and dung beetle populations. From June 1998 to June 1999, dung beetles were collected monthly at two adjacent ranches in Mexico. Ranches were similar in area, elevation, exposition, soil and vegetation, but they differed in weed control.
In ranch A, weeds were controlled manually, while the unwanted vegetation in ranch B was controlled with the application of Tordon 101M. The main species recovered from each ranch (A. apicalis) was significantly more abundant at ranch A than at ranch B. Conversely, similar numbers of a second species, A. sculptor, were recovered from both ranches.
Three lines of evidence support the tentative conclusion that herbicide applications may be causing a decline in populations of A. apicalis on ranch B.
First, the greatest reduction of A. apicalis was observed during periods of herbicide application.
Second, A. sculptor, apparently less affected by the same herbicide application, is active primarily during months without herbicide applications.
Third, preliminary results of laboratory studies show that the exposure to herbicide can impair the reproductive function of the dung beetle Canthon cyanellus.