Summer is here, and with it comes the dung beetle. The dung beetle requires manure as a food source for their offspring. The adults bury balls of manure down in the soil for their larvae to develop on. If you ever collect manure that has had dung beetles in it, you’ll see the holes in the soil. The activity of dung beetles is very useful in the control of the free-living stages of parasitic worms. In hot, dry conditions the aeration of manure pats by beetles is enough to fully desiccate the manure which results in the death of worm eggs and larvae. Therefore, if you have dung beetles on your property in summer, you no longer have to collect manure or harrow it. In cooler times, dung beetles may still be present and can lower the number of infective larvae emerging from pats by up to 74%. In your pasture management plan, you should aim to help and encourage dung beetles as much as possible. Not only dung beetles, but all the soil invertebrates that help to degrade manure. It has been found that over 200 different insect species call manure home, all which play an important role in manure degradation. One thing to avoid in summer is worming your animals. All classes of worming-drugs have a mode of action that means they are also toxic to a range of other organisms. Wormers are designed to kill nematodes (roundworms), and so drugs that pass out in the manure can have a toxic effect on free-living soil worms (such as earthworms). The mectin drugs (abamectin, ivermectin, moxidectin) are also toxic to insects, and so manure of treated animals can be toxic to a range of insects, including dung beetles. Different species of insect and nematode are affected in different ways. For example, dung beetles may still feed/aerate a manure pat of a treated animal however the beetle larvae die or undergo abnormal development. Overall, the presence of wormers in manure has a negative effect on the rate of degradation of manure. Therefore over summer, avoid worming your horses/livestock unless faced with a case of clinical disease. If you get FEC performed, it may be wise to increase the EPG cut off to 500EPG compared to the normal 200EPG. If worming is required, ensure that you collect the manure for the first week after worming to prevent ill effects from the high concentrations of drug in the faeces. This summer have a think about the humble dung beetle and the wonderful work they do. The world is full of species that thrive in what we consider waste – these small but mighty creatures play some of the most important roles in ecosystems. Additionally, if you don’t have dung beetles, there are places online where you can order them as well. A box of dung beetles in the post seems like such a nicer thing to receive in the mail than a bag of, well, dung.
Photo credit to University of Western Australia:
Bryan, R. P. (1976). The effect of the dung beetle, Onthophagus gazella, on the ecology of the infective larvae of gastrointestinal nematodes of cattle. Australian Journal of Agricultural Research, 27(4), 567-574.
Bryan, R. P. (1973). The effects of dung beetle activity on the numbers of parasitic gastrointestinal helminth larvae recovered from pasture samples. Australian Journal of Agricultural Research, 24(1), 161-168.
Errouissi, F., Alvinerie, M., Galtier, P., Kerboeuf, D., & Lumaret, J. P. (2001). The negative effects of the residues of ivermectin in cattle dung using a sustained-release bolus on Aphodius constans (Duft.)(Coleoptera: Aphodiidae). Veterinary Research, 32(5), 421-427.
Strong, L. (1993). Overview: the impact of avermectins on pastureland ecology. Veterinary parasitology, 48(1-4), 3-17.
Strong, L., Wall, R., Woolford, A., & Djeddour, D. (1996). The effect of faecally excreted ivermectin and fenbendazole on the insect colonisation of cattle dung following the oral administration of sustained-release boluses. Veterinary parasitology, 62(3-4), 253-266.
Photo credit to University of Western Australia: