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 Post subject: General discussion and interesting facts
Unread postPosted: Sun Dec 19, 2010 7:24 pm 
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RonnieL wrote:
Hi Guys,

I need some help.

I took this pic recently in the Addo Park of these butterflies sitting on fresh and still wet elephant dung.
I have seen this before in the park and also outside of the park where I have seen these same butterflies sitting on cow dung and even on the damp soil where livestock have urinated or any damp soil for that matter.

I want to know what are they doing and are they able to obtain liquids and nutrients from the dung and urine?


Hi Ronnie,
My apologies; I somehow missed your item. My excuses are age and stupidity; what are yours? :redface:

You said some very nice things, but really, you were too generous by far; embarrassingly so! What I know might fill a book or two, and more than half of it is more than half wrong, What I don't know doesn't fit into all the libraries on the planet!

Your question seems simple, but it opens whole cans of worms.

Let's see...

The life histories of insects vary in their functional organisation (how they work, if you like.) However, practically all of them have two different stages combined in one way or another. Generally the first priority is to build up a working adult insect, and the second is to get the necessary materials for producing babies and if necessary, caring for them.
Let's think of a few examples. I can't go into details; there is too much!

One simple case is a moth like an emperor moth (like the Mopane "worm"). The larva eats obsessively, building up stores of protein, water, and fat. When adult it doesn't eat at all, for its "strategy"" it doesn't need to. The female simply sends out a signal for the male to follow to mate, first come, generally the only one served. He then generally dies and she lays eggs in large batches. She makes them from her bodily food stores.

That was that! It is a simple strategy and works fairly well, even if it seems brutal. But it suits the moths; they have no reason to hang about afterwards instead of dying.

Hummingbird hawk moths and butterflies tend to live longer as adults. They might last for months and generally spread their eggs more widely, some species even laying their eggs singly and widely scattered, making life hard for parasites, parasitoids, and predators. Most of them have enough bulk proteins and fats to make eggs, but need more energy for flight, energy that they get from damaged fruit, nectar and so on.

Consider mosquitoes. Some kinds like the giant mosquito Toxorhynchites spp., eat other water animals when they are larvae, in particular the larvae of other mosquitoes. They certainly deserve encouragement! Such animal food is very rich, and the adults of both genders have no need to suck blood, so they just mate, suck nectar for energy, and lay their eggs in promising pools and tree-stumps where there are likely to be munchies, such as malaria or yellow fever mosquito larvae.

Other species of mosquitoes feed mainly on detritus and microscopic creatures in the water and they do grow into functional adults, with males that don't need more proteins, but do need nectar for energy, chatting up females etc.

The same applies to the females, except that the female needs protein to build eggs. She accordingly risks her life biting you and me. They both can live for weeks in suitable conditions, each with his slightly but crucially different life history.

Butterflies now, what about those butterflies, Richfield?

Butterflies vary, but especially those that live in forests have special needs. They can easily (if they survive!) get enough food to build up the bodies of the adults, but they are famous for eating sap, dung, mud, and so on. Butterfly collectors make use of the fact to trap specimens.

You see, especially in forests, plants are short of some minerals such as sodium and chlorine that most plants don't need, but animals do. Mud often contains a job lot of minerals, and you often find mainly male butterflies sucking up the mud's moisture for its dissolved salts. Manure and urine practically certainly contain such salts, coming as they do, from large animals that had to collect the salt, sometimes from salt licks, They need to get it somehow if they want to stay functional. Nectar, juice, and sap mainly supply energy in the form of sugars, and not much mineral content. Nice, but not critical. When the males of some species have collected and concentrated a goodly supply of the necessary salts, they chat up females and offer them some of their hoarded salt supplies. A female that likes the offer will mate, which she now can afford because she is not short of the salts of animal origin that she needs to produce viable eggs.

Get the picture?

Ciao for niao,

Jon


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 Post subject: Re: Insect ID needed
Unread postPosted: Mon Dec 27, 2010 9:15 pm 
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Location: Cambridge, MA (and home from home in Darling, WC)
Can anyone help with ID of this pupa or chrysalis? Is it for a moth or a butterfly or .... ?

Image

Seen in KTP in September 2007.


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 Post subject: Re: Insect ID needed
Unread postPosted: Wed Dec 29, 2010 9:35 am 
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Thanks Arks, but the first shot was as good as the second. Unfortunately the KNP is far out of my home ground, so I have very little feeling for their wild life. I think I have seen such cocoons worn as ornaments, but I cannot be sure that this exact type would be the one. You see, some of the likelier families are inclined to feed and pupate in groups.

I go along with Imberbe part way, even to the point of sharing his lines of thought. I too had been wondering about which Lasiocampids might occur in KNP:
Imberbe wrote:
I have been under the impression that these are lunar moth cocoons. I have often seen them in KNP and this is what I was told.

But since your question, I have done some digging. I am now less convinced that it is a lunar moth or even some other saturniidae.

I am beginning to think that it may rather be a moth of the Lasiocampidae Family (Eggar moths, lappet moths). This type of cocoon forming is well known in that family and yes, they do utilize acacia as well.


But then again, could it not be some sort of Lymantriid?

In case it is either of those two families, be cautious about handling such a cocoon; they often (especially the Lymantriidae) have their silk interwoven with their stinging hairs, and in fact, if I were to see one close up I should begin (very gingerly) by inspecting the silk for stinging hairs, using a good lens!

Why not just keep the cocoon and see what comes out, you ask? Well yes, but actually although the Lasiocampidae and Lymantriidae are pretty prickly, they tend to be heavily attacked by parasitoidal flies and wasps, and those are the likeliest beasties to hatch out!


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 Post subject: Re: Insect ID needed
Unread postPosted: Sun Jan 02, 2011 5:43 pm 
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Jon Richfield wrote:
Sorry, but you make me feel increasingly inferior!

Never!!! :roll: :wink:

Perhaps Imberbe will have something to add when he pops in again, but I know that he's also not very familiar with arid parks.

:idea: Perhaps I should now post it in Jannie's new ID thread under Arid Parks .... :slap: :doh:


Edit: I did post it in the Arid Parks "what is this" thread and you were both right about it. Here is Jannie's reply to my query there.


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 Post subject: Re: Insect ID needed
Unread postPosted: Wed Feb 23, 2011 10:36 pm 
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Another "insect-related" :wink: ID, this time two different caterillars seen in WCNP in October 2010.

Image

Image


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 Post subject: Re: Insect ID needed
Unread postPosted: Sun Feb 27, 2011 6:15 pm 
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[quote="arks"]Another "insect-related" :wink: ID, this time two different caterillars seen in WCNP in October 2010.

My apologies Arks, this is one of my humbler moments. The top woolly bear looks very much like a caterpillar of the
Arctiidae (Tiger moths). A lot of them look like that.

However, I don't know the other one; there really isn't much detail. It looks like a bad choice to handle without forceps, but it doesn't look very distinctive. It is pretty surely not a slug caterpillar (Limacodidae). It does not look to me like a Lasiocampid (they usually have conspicuous "whisker" bristles out front). Nor does it look much like a Lymantriid (the gypsy moth lot).
If someone told me it also was an Arctiid, I wouldn't argue, but really, I would be guessing.

Sorry 'bout that!

Cheers,

Jon


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 Post subject: Re: Insect ID needed
Unread postPosted: Mon Feb 28, 2011 12:01 pm 
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arks wrote:
No apologies, Jon, all this is very interesting. I googled "Arctiidae" and there does seem to be a lot of variety, covering both the pix I posted. Plus I had no idea that there were also "woolly bear" caterpillars in SA. Ours in the northeast US usually have stripes of brown and black, and there's a bit of local folklore that the amount of black indicates the severity of the coming winter.

Hi Arks, only a pleasure of course, as far as it goes. Yes, one of the problems with larval forms is that one often gets huge variety within a family, and the more widespread the family the more varied as a rule, and Arctiidae are practically cosmopolitan.
However, beware of taking Google pics to seriously; do indeed use them heavily, but few of them are reliably labelled, and some of the labels reflect the occurrence of a word within the article instead of the content of the pic.
You see, the only "woolly bears" most people know are Arctiidae, so as far as they are concerned, anything with bristles are Arctiids! Some of the caterpillars confidently labelled Arctiidae, I would put money on to be Lymantriidae!

If you google images Lymantriidae caterpillars, one hit is at http://www.bukisa.com/articles/274587_t ... imals-ever (worth a look, even though there are still cuter animals everywhere!) But that is stated in the text (correctly, I reckon) to be Arctiidae. What they DON'T mention at that site is that their cute caterpillar is not for thoughtless handling!!!

However some of the first pics on the google images page could easily be confused with Lymantriids. Both Arctiids and Lymantriids often have the pretty "hair pencils" front and back. Lymantriids however, are likelier to have "collars of short, defensive sharp bristles across the backs of two or three of the front segments. When alarmed they evaginate them to present the bristles, which are usually of a contrasting colour. A typical specimen is at:
http://www.richard-seaman.com/Arthropod ... ckMoth.jpg
Later!
Jon


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 Post subject: Re: Insect ID needed
Unread postPosted: Tue Mar 01, 2011 11:48 am 
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onewithnature wrote:
Thanks Jon. Yes, I've been fascinated with insects - often in rest camps - for decades, but have often struggled with ID. Nevertheless, watching their behaviour and awed by some of those colours and shapes means I can spend ages watching insects in camp while others are watching birds. I think, perhaps, the first actions I need to IDing them are to recognise classes. That, in itself, will take months, if not years. But, the world of insects is an amazing one that few people take the time to understand. If they did, soapies would be on the decline. :wink:



Oookay! Technically Insecta are a Class and what one usually needs is an introduction to the Orders, for example, Silver-fish, mayflies, grasshoppers, mantids, bugs, moths, beetles, wasps etc. For some examples one needs to get down to families, such as mossies, horseflies, tiger beetles, scarabs, spider-hunter wasps and so on.

Then there are the local prominent individuals. The Picker book is particularly useful for familiarising yourself with insects in general and with SA insects in particular. However, I have a feeling that we need a book with collected line drawing pics for guidelines. As a boy I learned basic order recognition from little handbooks from the British museum: Instructions to collectors. Their line drawings were excellent. I must look into such matters.


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 Post subject: Re: Insect ID needed
Unread postPosted: Tue Mar 01, 2011 4:52 pm 
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onewithnature wrote:
Thanks Jon. Yes, I've been fascinated with insects - often in rest camps - for decades, but have often struggled with ID. Nevertheless, watching their behaviour and awed by some of those colours and shapes means I can spend ages watching insects in camp while others are watching birds. I think, perhaps, the first actions I need to IDing them are to recognise classes. That, in itself, will take months, if not years. But, the world of insects is an amazing one that few people take the time to understand. If they did, soapies would be on the decline. :wink:


Right. I have found a page that could help for starters. Have a look at:

http://www.life.illinois.edu/entomology ... tions.html

As for people dropping soapies for science and biology, you are overlooking one worrying fact about human nature:

The people you meet here are unusual; they enjoy thinking.
Most other people can't take it any longer than they take to say "Gee- whizz!" when they see some biological violence in a watered-down and misleading nature program for kids.

Do I sound negative?
Perhaps I do.
But at least you now know part of why I appreciate you folks!


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