# a dearth of detrivores



## ErinM31 (Mar 15, 2016)

Isopods/pillbugs are generally easy to find. Where I grew up in the Chicago suburbs there wasn't much in the way of wild-life but one could reliably find pillbugs under wood, flower pots, etc., so long as it was warm enough. Now I live in a wooded area outside San Antonio and with warm weather nearly year-round plus a rainy season, there is quite a variety of flora and fauna and I amused everyone my first year here getting excited over lizards and walking sticks and the general variety (and size!) of the insects and arachnids.

Should be easy to find pillbugs here, right? Wrong.

I have looked several times over the past months, under piles of leaves and fallen wood overgrown with lichen and vines and epiphytes. I have looked after a week of rain when the world was warm and moist and seemed made for pillbugs. Still not a one.

Other types of arthropods abound (often literally bound, lol), yet not only isopods are strangely absent. As I go through these leaves and wood that seem a detrivore banquet I find... hardly anything. Sometimes I find ants. Often I'll see a wolf or grass spider. Sometimes I see nothing at all. If I dig in the dirt a bit, I'll find the occasional small centipede or millipede (not NEARLY enough millipedes to make me think they have displaced the pillbugs -- besides, the food is literally piling up...) and then lots of small empty snail shells. Sometimes I'll see living snails around here but that is rare and most often even they are recently deceased, having desiccated whilst trying to cross concrete.

So what is going on here? A disease or rather specific toxin? I am reminded of the scene from _The Fellowship of the Ring_ where the presence of the ringwraith causes all the bugs, all life, to flee from its evil presence... What foul essence has entered my woods?


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## The wolf (Aug 2, 2017)

I have no expertise my guess is in less biodiverse areas they have fewer natural predators and so this suits their breeding speed(I don't know how quickly they breed this is all just a guess) and so they are everywhere but in areas with more predators their breeding speed does not allow them to become abundant so the more secretive well hidden species are th only one that can manage.


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## ErinM31 (Aug 3, 2017)

The wolf said:


> I have no expertise my guess is in less biodiverse areas they have fewer natural predators and so this suits their breeding speed(I don't know how quickly they breed this is all just a guess) and so they are everywhere but in areas with more predators their breeding speed does not allow them to become abundant so the more secretive well hidden species are th only one that can manage.


Never mind this post as it was only my own naïvety.  At the time, I did not know that the isopods and Julid millipedes that I was accustomed to finding in the Chicago suburbs are all introduced species. I did eventually find the isopods around here but only in areas that have more moisture year-round (by rivers, irrigated lawns, etc.). There are several species of millipede native to the area that are seasonably abundant, in particular a species of Parajulid. Beetles, termites and larvae can be found in decaying wood. I still don't know, however, what creatures may eat the decaying leaves besides _Arenivaga_ cockroaches.


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## The wolf (Aug 4, 2017)

ErinM31 said:


> Never mind this post as it was only my own naïvety.  At the time, I did not know that the isopods and Julid millipedes that I was accustomed to finding in the Chicago suburbs are all introduced species. I did eventually find the isopods around here but only in areas that have more moisture year-round (by rivers, irrigated lawns, etc.). There are several species of millipede native to the area that are seasonably abundant, in particular a species of Parajulid. Beetles, termites and larvae can be found in decaying wood. I still don't know, however, what creatures may eat the decaying leaves besides _Arenivaga_ cockroaches.


They may not be directly fed on by an animal rather just rotted by mould although I doubt this the main part of the earthworms diet is dead leaves so it is likely they are dragging them into their burrows if you realy want to know you can use a variation on the berlese/tullgren funnel to see whats living in, and so probably eating the leaf litter.


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## Bunyan van Asten (Aug 5, 2017)

ErinM31 said:


> Isopods/pillbugs are generally easy to find. Where I grew up in the Chicago suburbs there wasn't much in the way of wild-life but one could reliably find pillbugs under wood, flower pots, etc., so long as it was warm enough. Now I live in a wooded area outside San Antonio and with warm weather nearly year-round plus a rainy season, there is quite a variety of flora and fauna and I amused everyone my first year here getting excited over lizards and walking sticks and the general variety (and size!) of the insects and arachnids.
> 
> Should be easy to find pillbugs here, right? Wrong.
> 
> ...


Just go to a rotten log in a part of the forest a little bit off the trail and go ham on it! Those things are isopod cities.


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## ErinM31 (Aug 5, 2017)

Bunyan van Asten said:


> Just go to a rotten log in a part of the forest a little bit off the trail and go ham on it! Those things are isopod cities.


I had always thought so, but in North America, that is only where humans have introduced them (most places now I suppose) and there is sufficient moisture (and this seems not to be the case in all microclimates in southern Texas). Termites and occasional beetle larvae are the main creatures I've found in rotting wood around here.


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