September 2012
For What It's Worth

A Healthy Pasture Ecosystem:

 


                      Close-up of a dung beetle.

Dung Beetles Provide Free Fertilizer and Reduce Parasite

As farmers, we must be well-diversified managers of our farms; we manage our livestock, facilities, animal health and nutrition, forages, public relation, and much more. This entails a significant amount of responsibilities and at times can be overwhelming. However, when all this is broken down into components and instead of looking at the big picture we look into each unique aspect, it becomes more practical to address. In working with various small animal livestock producers and producer groups, I hear of some interesting concepts and ideas. One of the most recent concepts brought to my attention is the role of the dung beetle or scarab beetle as its purpose in life is to break down animal manure and move the basic nutrients and organic matter into the subsoil. This enhances the overall quality of soils and improves the nutrient value of forages for livestock. The tunneling these beetles conduct during this process helps aerate the soil and facilitates the movement of water into the subsoils as well: a win-win situation.


The purpose in life of the dung beetle is to break down animal manure and move the basic nutrients and organic matter into the subsoil.
 

 

The aforementioned interaction constitutes an ecosystem. Wikipedia’s definition does a good job of supporting this. "An ecosystem is a biological system consisting of all the living organisms or biotic components in a particular area and the nonliving or abiotic components with which the organisms interact, such as air, minerals, soil, water and sunlight. Key processes in ecosystems include the capture of light energy and carbon through photosynthesis, the transfer of carbon and energy through food webs, and the release of nutrients and carbon through decomposition. Biodiversity affects ecosystem functioning, as do the processes of disturbance and succession. Ecosystems provide a variety of goods and services upon which people depend; the principles of ecosystem management suggest that rather than managing individual species, natural resources should be managed at the level of the ecosystem itself."

According to Wikipedia, dung or scarab beetles thrive throughout the world. "Like honey bees, different dung beetles have specific roles. Some are knows as rollers, rolling manure into round balls for ease of movement; others are known as tunnelers, burying the dung where they find it, and others are known as dwellers, simply living in the manure."

 

Based on what I have read and heard, dung beetles are more active following a rain and during warm seasons, particularly spring — typical of many insects. Their role in this soil-nutrient ecosystem is quite interesting. These beetles consume and bury manure in the soil by digging tunnels to facilitate movement. As the manure breaks down it improves nutrient cycling and soil structure. These beetles lay their eggs in the ground, larvae hatches, and the larvae eat the dung and gastro-intestinal parasites found in the dung. According to an article posted by Charles Griffith, a writer for The Samuel Roberts Noble Organization Inc., he interviewed Dr. Truman Fincher, an entomologist at Texas A&M University, who stated that well-established populations of dung beetles can break down small piles of manure (four to six inches) in three days.

In the same article, Fincher talked about dung beetles controlling horn flies and gastro-internal parasites. He explained horn flies and internal parasites complete their life-cycle in manure piles, dung beetles consume and break down manure; they also lay eggs where larvae consume these parasites. Their tunneling action aerates the soil. All this serves to interrupt the life-cycle of these parasites. According to the entomologist, farmers and ranchers spend over 800 million dollars per year attempting to control internal parasites, while the dung beetles do their job at no charge.

Whether we have horses, cows, goats or sheep, there are times we utilize chemicals to reduce infestation of gastrointestinal and external parasites. Some of these chemicals are nonselective and kill good and bad insects. According to one resource "wormers ending with ‘mectin’ are toxic to the dung beetle." The same source also alleges "the ‘mectin’ wormers have a limited toxicity time frame. And, wormers ending in ‘zole’ are not toxic to this beneficial insect, another factor to consider when determining which type of wormer to use during certain times of the year."

What does all this mean to you and your farm? Most of us know the cost of fertilizer is about $550 per ton, which makes it costly to fertilize your pastures. Most of us also know that for some time soil scientists have been encouraging farmers to minimize tilling of soil and instead use no-till methods facilitating the build-up of organic matter in our fields. From what I have read, were it not for the actions of the dung beetle, some of the nutrients in livestock manure would evaporate as they break down, as opposed to being worked into the soil by dung beetles. As I said earlier, the dung beetle is breaking down these manure piles into soil nutrients and organic matter, using tunnels to move these products into the subsoil, and putting in free fertilizer and beneficial organic matter improving the quality of forages your animals graze. They are also helping to reduce the impact of external and internal parasites on your farm and in your animals; all this at no charge to you!

Does that imply all of us should quit our day jobs, start raising dung beetles to sell to other farmers and stow away the profits for retirement? I think not! But, I do hope this encourages you to walk out into areas of the pasture where your animals loaf around the barn or graze, look for evidence of scarab beetles, then consider the health status and benefits of the ecosystem in the soils of your pastures, and have a greater appreciation for the habitat of this insect.

Information Resources (all retrieved 5/14/2012):

"Dung Beetle" http://en.wikipedia.org/wiki/Dung_beetle
"Dung Beetle"
http://insects.tamu.edu/fieldguide/bimg146.html
"Dung Beetles"
http://www.noble.org/ag/pasture/dungbeetles/
"Dung Beetles"
http://www.vevs.com.au/site/index.php? option=com_content&view=article&id=123

Robert Spencer is an Urban Regional Extension Specialist with the Alabama Cooperative Extension System.