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Monday, April 24, 2017

Identifying a spider from a photo

I get sent a lot of photos which people hope I can identify. I love getting them - I only wish I could do better on identifying. If they are common Australian spiders, I have a chance. With thousands of species identified in Australia alone and many more thousands yet to be described by science, my chances of recognising a spider from a photograph is small. When they come from other countries, I am often struggling to even know the family.

The problem is made worse because the photographs often don't show me what I need to know and the senders don't include the necessary information. I need to know where the spider was photographed - not only the location but whether it was associated with a web (really important), near houses, in a burrow, in dry bush or wet forest and so on. With the photos, most are blurry. As I need to see details like the hairs, that makes life difficult.

The eyes have it

But most useful of all are the eyes. Almost every spider photo is taken of its back. Spiders are often identified to family level from their eye pattern.

Today's photo included the eyes! Rushil Gupta sent me three photos of a spider to identify. The first gives you an idea of the entire photo, and the smallness of the spider in it. The next three are zoomed and cropped. [Click on images to see them better.]


The shape suggests a few possibilities. An arachnologist might be better able to leap to conclusions, but it is too blurred for me when I zoom on the spider:


This is clearer, and I am getting a good idea. But I still can't see what I need.

 

And the really useful one! I have the eye pattern. It has a large front pair of eyes ... jumping spider or wolf spider or lynx spider? The photo is clear enough to see the very strong spines on its legs, which indicates probably a lynx spider (family Oxyopidae). But it is the eye pattern which will clinch it - and Rushil's photo shows them.


A great site for the eye patterns of the common families is Bugguide:


This is found at http://bugguide.net/node/view/84423 (or click on the image). It shows the Lynx Spider family eye pattern to be:


Bingo! NOT! I jumped (pun intended as will be obvious soon) to conclusions too fast! Fortunately some experts jumped in - thank you Lizzy Lowe and Alan Henderson. The two little eyes under the large anterior median eyes aren't there!

I thought that I could see spines on the legs which is why I headed for lynx spiders. Clearly, I judged that wrong too.

Try again: This is the eye pattern of the jumping spiders, family Salticidae. So Rushil's spider is definitely a jumping spider.



From the bulges on the end of the pedipalps at the front, I would guess that he is a male wandering in search of a female. Now I need to hear back from Rushil to know what country the spider comes from. I can work out the size from the image!

UPDATE: Rushil tells me that he is in India. I'll wait for the experts to see if they can tell me more.

CONCLUSION: I am really good at loving spiders and observing my locals. I am no good at ID unless it is one of my locals - much as I would love to be and will keep trying.
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Thursday, January 26, 2017

Zoe's golden orb weavers

Zoe Stanford showed me a photo of a strangely coloured spider. The only possibility seems to be a golden orb weaver, Nephila edulis. (Click on images to see the detail.)


Zoe let me know of a new young golden orb weaver who had arrived. I asked her to take a series of photographs to show the way Nephila build up their set of debris above them on the web to act as a confusion for predators. This is the sequence she sent.





This is the final image of the spider, her web now full of junk.


Unfortunately, she has built her web in a place which had no protective foliage nearby. After a severe storm, Zoe found her spider dead in her web. So sad!

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Thursday, November 3, 2016

Please meet The Regulars

Each year I have a group of spiders who I visit every day or night, depending on who and where and when they are out and about. I will blog some of them as The Regulars. Here's a few to start with.

The stunners as usual are the garden orb weavers. We'll start with two, both Eriophora pustulosa, (family Araneidae) the most common species here in Castlemaine. I have named them, rather unoriginally, Erio-first and Erio-second. They live in the car-port and under the roof slats of an outdoor space respectively.


I have so many blackhouse spiders that I would love to introduce, mostly Badumna insignis (family Desidae). There's Badumnina on the kitchen window. And Bumdiddy, who has to date always had her rear end protruding from her retreat. I have never seen her otherwise. Fortunately, she has a very cute rear end. Plus Equinina, so named because she lives behind an outdoor art work of a horse. There's also Bedheadia who lives just above my pillow in my bedroom. She's the little cousin, Badumna longinqua, a brown house spider. The photo is Stoned, a full grown female blackhouse who lives in the stone wall and was weaving silk at a frantic rate tonight.


There are lots of daddy long-legs, of course (Pholcus phalagiodes, family Pholcidae). Please meet Violet-long-legs. She lives behind the African violets in the bathroom.


And then there's a confusing little spider. I had no idea what she was. A Facebook callout and Trevor Leaman had her sussed within minutes. She's a bird dropping spider, just not the one I am used to. We think that she's Celaenia calotoides (family Araneidae), so I shall call her Celaenia because it is such a pretty name. 


There is a lot more to say about each of them and quite a few more. Badumnina in particular is being very active and interesting. But that will all have to wait for further blogs.

It is so good to have the season off and running!

Friday, June 17, 2016

Deadliest animals? Spiders don't crack a mention!

It is lovely to see the statistics so beautifully presented. These are the deadliest creatures in the world, and spiders don't crack it for a mention. Lovely!

From the blog of  Bill Gates.


Friday, April 15, 2016

A donation from Ron DePaepe

            Ron has sent some photos and descriptions of his spiders. I love getting this stuff!

1. A spider commonly known as a bridge spider, or grey cross spider, depending on who you talk to. Proper name is Larinioides sclopetariusI prefer the common name of bridge spider, since I see them on or around man-made structures almost exclusively. I found this one in my yard at my former house and captured it in a large empty jar to get several photos. Her overall size was about an inch body length. She was likely not quite fully grown. After admiring her for several minutes, and photographing her from various angles, I released her exactly where I found her. She didn’t seem to be much the worse for wear, as she created a web nearby and remained in my yard for several days before disappearing. I assumed she was likely eaten by a bird.












2. This is a great shot of a member of the Theridiidae sp. Known as the common house spider or American house spider. This pretty female lived for a long time in the doorway between the kitchen and living room of my former house and one day I noticed there were babies. I took a lot of photos of her and her new brood of youngsters, and of all the photos, this one turned out best. At my new house, these spiders aren’t in the house, but seem to thrive in my garage. I found a dozen there one day while trying to straighten it up. As I saw it would disturb their webs, I finally gave up trying to clean the garage. Anything to get out of work. 




 2. One of the several adult female Wolf spiders I captured that produced egg sacs, which resulted in the six month experience of raising several hundred infants from three different females. The female I told you about in our chat, the one that I remember watching make an egg sac, was never a mother while in my care, having laid infertile eggs. Known as the Hogna helluo, they have been recently been reclassified as Tigrosa helluo. Same spider, same name, same species, just an update for whatever reason the arachnologists have. It’s all a part of the taxonomy game, I suppose






Friday, March 11, 2016

Arachnophobia - a reader responds

Ulla Jessen wrote to me from Denmark about recovering from arachnophobia. I was so delighted I just had to share it here (with permission, of course). Ulla wrote:


I am currently reading your book on spiders. It is truly one of the most exciting books I have ever read.

Like you, I suffered from arachnophobia for many years, until one day, at the age of about 30, when I decided that it was too ridiculous and I started to observe the spiders instead. 
I started with watching a 45 minute film on our newly acquired colour television. I sat right in front of the screen with my heart pounding for the whole time. It did work, now it was easier for me to go up to a small spider and just look at it.

Anyway, it went from there to being totally fascinated by the beautiful creatures.

Just like you I have given some of my spiders names. I had one in the kitchen when I first met my husband. He saw this black thing in the top corner of the kitchen and asked if I knew I had a spider there. I said yes, that is Herbert and he lives there. This was before I knew that it probably was a female. My husband to be was not too pleased and asked a few times is Herbert had to live with us and I told him "Love me and love my spider, Herbert stays". (After 28 years I am still married to the same man). 

My "mission" in life is now to teach my grandchildren not to be afraid of spiders. It seems to be working, just a bit. Two of my granddaughters of 14 years of age have actually sent me photos of spiders.

I have a friend who is rather afraid of spiders. She actually went with me to a large exhibition of live spiders in Copenhagen a couple of years ago and it has changed her attitude towards spiders. Her granddaughter sees a spider and asks her grandmother "Should you not take a picture of it and send it to Ulla?"

Even by husband is now able to see a spider without calling me to remove it. He even puts up with me reading aloud from your book at night in bed.

I have been looking on YouTube at videos about spiders. One thing that really annoys me is that although they seem to want to teach you not to be afraid of spiders, they still present them with horror-film music and dramatic voices like this is something to be afraid of. 

Here is a link to my video on recovering from arachnophobia. It has been viewed over 32,000 times so hopefully it may have affected someone positively.

Confronting the spiders

Ulla asks about good videos about spiders - I'd love to know more and add them to this blog. Please send me suggestions!

Ella wrote:
Do you know of any documentaries about spiders where they present the animal in a normal way, with love and admiration? 

I don't suppose I'd ever get to Australia, but if I did, I would love to see your forest of white cutlery.

Anyway, forgive my ramblings. I just felt the urge to share my little story and to tell you how much your book means to me, and as I said, if you know of any good videos of spiders, I'd love to know.

Thank you, Ulla!

Reader suggestions: 

Thanks Rachael! The peacock spiders:


Thank you, Kathleen, for pointing to the sand spider video:



Wednesday, January 13, 2016

I always love the black house spiders

Unlike the orb weavers who make a stunning show in summer then disappear, my black house spiders are a constant presence.

Please meet Lily, my favourite this year. She lives behind an outdoor art work of a lily hanging on the verandah, hence her name. Lily is a black house spider, Badumna insignis.

When I first met her, Lily was quite large in the abdomen. (Spiders don't mind you mentioning this.) She was gravid, ready to lay her eggs.


She appeared less often, but did come out for dinner one night.


A few weeks later, and her babies emerged with her. They only hung around a few days and were gone.


If you click on the photo below and look closely, you can see that her fangs work inwards like pincers. She is a 'modern' spider, an araneomorph. The so-called 'primitive' spiders like the trapdoors, Australian funnel-webs, tarantulas and mouse spiders, have their fangs pointing down so they raise their bodies to strike. They are known as mygalomorphs. You can also see her little claws which she uses to hold onto the web. Gorgeous creature!




No more photos. Good night.