Wednesday, 10 January 2007

#3 A Cricket earns his Wings

Until I found this Raspy Cricket on my back porch, I thought the only crickets that lived here were the black field crickets that we used to use for trout bait.

Impressive fellow, isn't he?


Observing a Striped Raspy Cricket Paragryllacris combusta (family Gryllacrididae) both as a nymph and an adult in my backyard was a real treat. When I first spotted the wingless nymph it was clinging to the eaves above the kitchen window.

The nymph's long thread-like antennae were coated in strands of silk as it wandered through a spider's web. Consequently the antennae became tangled around the cricket's front legs and he spent several minutes cleaning them. It was fascinating to watch this grooming process from an up-close vantage point.

Cricket nymph gets in a bit of a tangle.....


.....then grooms his sensitive antennae


But as I moved in for a closer look, I soon found out why this cricket's common name was 'Raspy Cricket'. Initially uncomfortable about my intrusion, he raised his quivering rear-end and emitted a sound that could be likened to two pieces of sandpaper rubbing together. I presume that mouth could inflict a reasonable bite too!

Two days later I was excited to find a winged adult Striped Raspy Cricket in the shed. It was pale and lethargic and appeared to be recovering from a moult. It soon became brighter and more active, although not yet prepared to fly, so I had an opportunity to further study it's appearance and behaviour. They shed their skin 5 to 7 times as they grow, then become winged adults.

My hand gives a size perspective of the adult cricket

While the cricket was resting on a cardboard box I spent time checking out the finer details of this impressive insect. Raspy Crickets are expert climbers hiding by day under bark or in abandoned insect tunnels and feeding at night on a variety of insects and some vegetation.

They are also well equipped for digging and cutting through grass roots with wide 'blades' and sharp claws on their feet (see a close up of front feet in first photo).

In the following picture you can see a structure at the rear end of the cricket that resembles testes. This is another indicator that this male cricket may have recently moulted or mated, and although this testes-like feature is part of his mating aparatus, it is not testes as these are internal and much larger. These external parts will withdraw into the body when he has hardened up or 'readjusted' himself.

Rear-end features of male Raspy Cricket

The male Raspy Cricket is readily identifiable by the presence of the two rear-end spikes, whereas a female will have a long sabre-like ovipositor on the back end which they use to insert eggs deep into the ground or bark according to species.

The picture below shows a forward facing curved spur on the front leg. Both sexes have the spurs so it isn't something that only one sex requires. Unfortunately the biology of a lot of our insects is very poorly known, and the purpose of these spurs has not been recorded.


A close-up of the adult Raspy Cricket shows many features including the front leg spur

Amateur nature enthusiasts can, and do, make useful and important observations and discoveries in the world of nature.

10 comments:

Jack West said...

Congratulations Gaye, a very informative study. As you have proved there is much we can all learn in our backyards. I look forward to more revelations.

Jack

Maria said...

That was great. I love the pics and its very informative too, I found it all really interesting

Gaye from the Hunter said...

Thanks Jack. I am continually delighted by the small creatures visiting and breeding in my backyard that is only in it's early stages of development.

Gaye

Gaye from the Hunter said...

hi Maria, thanks. I'm glad you enjoyed my beaut cricket. I'll have lots more fabulous creepy crawlies to share.

Woollybutt (Peter) said...

Nice work Gaye,

your close up shots are brilliant.Crickets intrigue me, they look like something designed in a Hollywood special effects studio. I also think the same for weevils, I can never look at one without smiling.

I'm going to have a look at a few more of your posts before I go.

Cheers
Woolly

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Gaye from the Hunter said...

Thank you for your comments Peter. The cricket was very cooperative when I stuck my camera in his face. I climbed on a ladder and watched him, keeping some distance until he became reasonably comfortable with my presence, then moved in closer.

I agree that crickets are beautiful and fascinating creatures.

Regards
Gaye

Evan said...

Hi Gaye,

This isn't related, but I was wondering whether you would be able to help. You said that you had done some fungi hunting in Barrington Tops. I have these photos of fungi from Barrington, and was wondering whether you would be able to ID them.

I understand it is very hard to ID fungi, but I was hoping these guys were distinctive enough. I'll be happy to ID any frogs you cannot :).

http://www.flickr.com/photo_zoom.gne?id=368565935&size=l
http://www.flickr.com/photo_zoom.gne?id=368565929&size=l
http://www.flickr.com/photo_zoom.gne?id=368565923&size=l

Thanks,

Evan

Gaye from the Hunter said...

hi Evan,

I am going to establish an email link on my blog home page so that I can be contacted easily for off-topic comments/questions, but I certainly welcome your question.

Yes, fungi are extremely difficult to identify without details to accompany photographs, but I have seen and photographed hundreds of fungi in Barrington Tops NP, so here's my attempt at ID:

id=368565935 I can't even guess at this one although I have taken similar photographs on 35mm before I started recording identifying features.

id=368565929 Quite possibly Amanita punctata

id=368565923 Quite possibly Tyromyces merulinus

There are a few fungus enthusiasts at http://www2b.abc.net.au/science/scribblygum/ who would be happy to chat about your finds and attempt to identify them. Hope this helps.

Cheers
Gaye

Henry Walloon said...

Gaye

Thanks for the informative comments on my blog.

The closeups are superb. What equipment did you use to acquire them?

Gaye from the Hunter said...

hi Henry,

I am fortunate to have two digital cameras. I have a little 'point-and-shoot' that I take everywhere with me. It is nothing fancy and I use it set on auto-everything all the time. I used this for the pictures of the whole crickets.

My other camera is an SLR (Canon 300) with a Sigma 50mm macro lens. It is not a dedicated macro, but it still does a good job. I used this camera to get the close-up shots. You can see that the depth of field is extremely limited. When I am using the macro lens, I rest the camera on a wheat bag to limit camera shake.

These crickets were great subjects because they were not in a hurry to move on. I will not be able to use my macro lens with grasshopper shots, however, because grasshoppers rarely stay still. So when summer gets here I will stalk the hoppers around my backyard with my little point-and-shoot camera :)

Cheers
Gaye