Sunday 2 June 2013

do you know shit!?


A stranger was seated next to a beautiful women on the airplane when the stranger turned to her and said,"Let's talk. I've heard that flights go quicker if you strike up a conversation with your fellow passenger."

The beautiful women, who had just opened her book, closed it slowly and said to the stranger,"What would you like to talk about?"

"Oh, I don't know", said the stranger, "How about nuclear power?"

"OK". She said. "That could be an interesting topic. But let me ask you a question first.... A horse, a cow, and a deer all eat grass, the same stuff. Yet, when you look at their droppings, a deer's poop is like little pellets, while a cow produces a flat patty, and a horse's looks more like clumps of dried grass. Why do you suppose that is?"

The stranger thinks about it and says, "Hmmm, I have no idea."

To which the beautiful women  replies, "Do you really feel qualified to discuss nuclear power when you don't know shit?"


These little guys really know their shit!


There are a range of insects from several different genera (e.g. Onthophagus, Copris, Heliocopris) which like shit/dung.  They use it to make nests for their young to hatch and grow in.  And why should this be of interest to us?  Well, dung on pastures makes a few problems for us.  It covers the pasture so reduces the available forage area, and pasture productivity.  It allows for the breeding of some parasitic worms, and it allows the breeding of some nuisance dung breeding flies.  However, dung beetles, by burying dung remove it from pastures, and in the process, aerate the soil, reduce nitrous oxide emissions, improve soil fertility and reduce the environmental availability of dung for flies and gut parasites.
In New Zealand the hopes of some agricultural scientists had been pinned on a little (6-8mm) insect called Onthophagus granulatus Boheman which is a native Australian dung beetle that has been established here for about 130 years.
 I heard that Landcare were working on dung beetles so I did a search of the literature to find out what was happening.  I found a paper by Dr. Shaun Forgie discussing some work he did back in 1992-93 and published in New Zealand Entomologist, Vol 32: 76-84,  in 2009 (Reproductive activity of Onthophagus granulatus Boheman (Coleoptera: Scarabaeinae) in New Zealand: Implications for its Effectiveness in the control of Pastoral Dung.)
I was getting quite excited about shit by then!  Sounds a bit sick!  However, when I had a thorough read of this paper it turned out that Onthophagus granulatus Boheman was a bit of a disappointment.  It’s a bit small to get much shit burying done very fast and it likes warmer temperatures (optimum 25o C) than we have in most New Zealand pastures.  If you look at the number of growing degree days (GDDs) you can get in a season and over what period of the year these GDD s accumulate it means that the poor little bugs can only manage one brood cycle per year (i.e. they are univoltine) which also limits their usefulness.  High soil moisture and dung quality (good grief! Can dung have ‘quality’ – well yes, it can be a bit sloppy! Yummy thought but very important to a dung beetle!) along with the temperature issue tends to limit the ability for these beetles to bury more dung!  It turns out that these beetles are also a bit slow at burying dung to be useful.  Each female only buries 131-196 grams of dung per brood ball.  When you compare this with the average brood ball weight of Heliocopris dilloni which is 364 grams and which have been observed to bury a 2kg dung pad in 45 minutes you can see what I mean!
Anyway, all is not lost.  As I said before I had heard that our heroes at Landcare Research were onto it.  In Issue 5 (June 2011) – (News about Landcare Research science relevant to the Ministry of Agriculture and Forestry) I read that they have been breeding colonies of exotic dung beetles for release.  In February 2011 the Environmental Risk Management Authority (ERMA) approved the Dung Beetle Release Strategy Group’s application for the importation and release of 11 species of dung beetles in New Zealand.   Staff at Landcare Research travelled to Australia to collect specimens of three types of dung beetles that are now being bred in containment at Lincoln.  Landcare Research is also planning to import breeding stocks of further species from Australia, and others from South Africa and France.
view the Landcare team getting into it at http://youtu.be/DNM3014VuP4

So ...watch this space.  That was in 2011, so maybe even now, as you read this, in a pasture near you, there may be some new types of dung beetle going to work and actually enjoying it!
view paper at:
New Zealand Entomologist, Vol 32: 76-84,  in 2009 (Reproductive activity of Onthophagus granulatus Boheman (Coleoptera: Scarabaeinae) in New Zealand: Implications for its Effectiveness in the control of Pastoral Dung.) http://dungbeetle.org.nz/references/

and more info at
http://www.landcareresearch.co.nz/publications/newsletters/maf/Issue-5  Accessed 3rd June 2013.

and at dungbeetle@org.nz

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