More than 450 species of insects can be found in cattle dung in North America. Some of these species (e.g., stable fly, horn fly, face fly) are important pests of livestock and have received a great deal of attention. 

However, the vast majority of insects in dung are beneficial and have received much less attention. For example,
Sphaeridium scarabaeoides (Hydrophilidae) (left) is a beetle common in cattle dung and feeds on the eggs of pestiferous flies. Unfortunately, these beneficial species have received little attention. 

The information presented here is to increase reader awareness of these many beneficial species.


"Dirty deeds done dirt cheap"

In a paper titled "The potential value of dung beetles in pasture ecosystems", Fincher (1981) identified four main ways in which dung beetles (Scarabaeidae) benefit mankind.  With consideration to the published literature, he calculated the potential annual value of these four services in the United States as follows:

1)  Increased grazing.   By accelerating the degradation of dung, dung beetles return areas of pasture to grazing that would otherwise have been covered by dung.  For beef cattle - $603,196,580.

2)  Nitrogen recycling.  By incorporating the dung back into the soil, dung beetles return tons of nitrogen to the pasture ecosystem that otherwise would have been lost into the atmosphere.  For beef cattle -  $208,164,384.

3)  Reduced parasitism.  By feeding in the dung pat and causing it to dry out more quickly, dung beetles disrupt the lifecycle of helminth parasites hatching in the pat, and thereby reduce the incidence of parasites in cattle.  For beef cattle - $428,061,500, for dairy cattle - $163,937,690), for other livestock - $150,000,000.

4)  Reduced pest flies.  By drying out the dung pat, dung beetles also reduce its suitability as a breeding site for pestiferous flies.  For beef cattle - $515,000,000.

Combined for these four services, the potential benefits provided annually by dung beetles to the United States totals $2,068,360,154 (in 1981 $).

Additional benefits

* Other benefits identified by Fincher (1981), but not included in his calculations included:  i) increased forage yields arising from the incorporation of organic matter into the soil, and a resulting increase in water retention, aeration, and soil friability;  ii) reduction of other livestock pests breeding in cattle dung;  iii) reduction of animal diseases by removing contaminated dung from the surface of the pasture;  iv) return of nutrients other than nitrogen to the pasture ecosystem, and  v) increased aesthetic value of the countryside.

Regardless of whether one agrees with the above calculations, they do serve to illustrate the many ways in which insects in dung benefit mankind.

Click here for a list of species associated with cattle dung in Alberta.




____________

References

Fincher, G.T. 1981. The potential value of dung beetles in pasture ecosystems. Journal of the Georgia Entomological Society 16: 301-316.