possumpete 的最愛

RIGHT fine Camponotus time. Again. Why are there so many of them?? Oh well, let's do the same thing as with Rhytidoponera. But like... more. -_-

Here in Australia we have 147 species and subspecies of Camponotus, at least according to AntWiki. Let's go through and rule out easy things, then we will go through with a finer comb and the use of this key. Keeping only those which might be vaguely in range brings us down to a much more manageable 37 taxa. And ruling out some more due to obvious morphological differences (plus species that I have seen and know well) brings us down again to 26.

Alright, where to now? Let's go through the key and see where we get (plus some general observations). C. consectator is poorly-known, and although the type location is listed as just 'Australia' there is a synonym from WA. I will discard it because I doesn't really look right and I suspect we are not in range. In C. claripes the propodeum is quite strongly raised and rather steeply horizontal to the rear, which is not the case here so it is out. C. fieldeae and C. humilior have parallel head sides so they too are out. C. froggatti, C. insipidus, C. pellax, C. spinitarsus, and C. wiederkehri have a very thick head and really quite different proportions, so they also are out. C. janeti has an even more extreme version of the same so once more, out! C. punctiventris is rather hairy with a very 'hunched' mesosoma, so not that one either. C. rubiginosus is black and red so again out.

Down to just 14 now, excellent! Now it becomes rather difficult though. C. crenatus is supposedly entirely black, and the head of the major worker appears to be a bit too short. Not a great angle for looking at my major workers though unfortunately, but I am happy to remove it. C. eastwoodi seems to have a dark head in both major and minor workers, and the major worker's head has almost parallel sides - in mine they definitely converge anteriorly so I am happy to rule it out as well. In C. subnitidus minor workers the sides of the head diverge anteriorly so again, I will rule it (and its subspecies) out.

Down to ten now. Okay, so of note in mine is that in the minor worker, the sides of the head converge posteriorly behind the eyes when viewed from above, and the section of the head behind the eye is longer than the length of the eye itself. Hopefully we can use this to rule out some options, but that does mean that I need to go looking for minor worker images. C. discors have a shorter and more parallel head, so they are out. However, in the description for the subspecies C. d. yarrabahensis it is stated that "the head is ... much narrower and longer". So for now I will keep the subspecies and see if I can find images. C. gibbinotus similarly has a rather short back of the head, as does C. loweryi. C. novaehollandiae is close but seems not quite right - I'll keep it for now and hopefully rule it out later. C. crozieri, C. extensus, C. rufus, C. simulator, and C. tricoloratus workers seem to have a similar head, so those are my options now (plus C. d. yarrabahensis and C. novaehollandiae).

So down to 7 now - how do we rule them out?? Another thing to note in my minor workers is that the antennae are very long. The scape extends past the posterior margin of the head so far that about half of its length (maybe more) is past the head. Hopefully this feature can also help! In C. crozieri it is a little short but probably still about right. The description of C. d. yarrabahensis states: "The scape extends beyond the posterior margin of the head by more than a quarter, almost a third of its length". So the antennae are too short there and it is out. C. extensus is a good match. In C. novaehollandiae the antennae are much too short, so it is out. C. rufus is also a good antennal match, as is C. simulator. C. tricoloratus also seems a little short but not too bad.

Five options now, and just looking at them I think C. extensus is the best option. I have seen this one before and it really does look correct. C. simulator is not too far off though, so we shall see what it turns out to be.

C. rufus was described from WA and the majority of the sightings are from near Perth, with just a couple of outliers which may be misidentifications. All of the images and descriptions of them show a rufous body and black abdomen though, which mine clearly do not have. So I am happy to exclude it, bringing us down to four.

Okay, so let's have a look at C. crozieri. The colouration is not really right, and my ants don't really look like they belong to the C. maculatus group. Additionally, the description given with that species group indicates that the "nests are in clay soil, never in sand" - this area is very sandy and I think it's fairly obvious that the nest substrate is sand here. So C. crozieri is out.

And looking at C. tricoloratus I have similar comments about the colour not being right - all workers seem to have a dark head and gaster with a pale mesosoma, which simply is not the case in mine. Additionally, AntWiki states that C. tricoloratus is "A species of semi-arid and arid habitats". Watsonville does not even come close to classifying as semi-arid, so C. tricoloratus is out.

Okay, so, it's between C. extensus and C. simulator. This might be tricky. C. simulator is unfortunately not included in the key so we will have to just look at them and read the descriptions to see if we can glean a difference. Both are certainly in range, and in fact the types of C. simulator are from Herberton and Atherton. Putting them right next to each we see that they really are very similar to each other. There seem to be a couple of minor differences that I can't make out in my images (e.g. posterior face of petiole slightly concave in C. extensus, slightly convex in C. simulator). I think there are two key features which I can see on mine and which seem to separate the two. Firstly, the positioning of the eye - if we draw a line along the longest length of the eye, in full face view these lines converge anteriorly in C. extensus and posteriorly in C. simulator. And secondly, the shape of the dorsum of the mesonotum and propodeum - in C. simulator the boundary between these two regions seems to be rather constricted, and in C. extensus it is more evenly parallel-sided. In mine, there is no constriction here and the eyes converge slightly anteriorly, both of which are good features for C. extensus. So yes, I am pretty sure I have C. extensus here. (And @reiasai97 agrees, woohoo!)

Released after becoming entangled in one of our lines.
Banded on right leg: green/metal, #194230. Reported to the NZ Banding Office, Department of Conservation. Advised just before we got back to shore that this bird was originally tagged as a chick at Miranda on 21 December 1997.

Honestly one of the best reptile experiences I've ever had - this stunning little goanna was splayed out on the path soaking up the sun and paid zero attention to me even when I took some nice closeup shots! Absolutely beautiful creature - look at the size of those claws! It was also halfway through shedding so there were some pieces of skin coming off everywhere. I couldn't resist a little 'handshake', but most astonishing of all it was still there two hours later when I was walking back! He had changed position a bit but was still so chill.