New year, new home, new job, new species

Apologies for the lack of recent posts. I moved at the end of November to start a new job in Talgarth, Wales. Following my move it took my ISP a whole month to set up my connection here, with a lot of extended phone calls and a rather long and comprehensive written complaint from me to get them to sort it out as quick as they did. Needless to say I am not best pleased with the company.

One rather important event that took place over the last month was that my recent paper was published, describing a new species, Monomorium subcomae. It may not be much, but it is my first new species. (I don't have the time or resources to conduct large scale taxonomic reviews. At the time I did the M. subcomae work I was working off of a table in my kitchen - at least now I have a dedicated office/lab.)

The type material for M. subcomae was collected in Kuwait by David M. King, though Mostafa Sharaf has already informed me that he has the species from Egypt. The specimens gradually found their way to me through Brian Taylor, along with numerous other tubes from around the Mediterranean.

M. subcomae is one of many species in the Middle East and North Africa that are related to Monomorium areniphilum, all of which have a propodeum that it on a distinctly lower plane than the promesonotum, as well as large eyes and distinctive striate sculpture on the head. Not many of the areniphilum-complex are bicoloured, so this makes M. subcomae relatively easy to identify. The key in Collingwood & Agosti (1996) can be easily adapted to include M. subcomae as follows:

17	Eyes large, greater than 0.25 times HW		17a
	Eyes small, 0.25 times HW or less		18
17a	Ventral surface of head with numerous long setae		subcomae
	Ventral surface of head glabrous		venustum

As yet nothing is known about the ecology of M. subcomae. Perhaps over time people like Mostafa will be able to fill in some of the details.


Citation and abstract: Lush, M. J. 2008. A new species of Monomorium (Hymenoptera: Formicidae) from Kuwait. Zoology in the Middle East 45: 67-72.

New species

I honestly can't remember the last time a new species of invertebrate was found in the UK (excluding bacteria from the definition). That makes it quite an event when something as significant as a slug is found, sort of the British equivalent of the Vu Quang ox.

The slug was described by specialists at the National Museum of Wales and Cardiff University, who named it Selenochlamys ysbryda, after ysbryd, the Welsh word for ghost. The beast is subterranean, lacking pigmentation and blind. It spends its time eating earthworms.

Sadly though, S. ysbryda is probably not native to the UK, as its nearest relatives live in the mountains of eastern Europe, Georgia and eastern Turkey. Because it may have invaded British shores, the National Museum of Wales are seeking any additional records, to see how widespread it is, and have provided an identification guide.

More information can be found at the National Museum of Wales website and BBC News.

I ♥ morphometrics

Put simply, morphometrics is 'measuring shapes'. In the normal, biological context this refers to the shape of study organisms. It is used by the taxonomist as a way of determining species boundaries.

Not long after I first encountered morphometrics I found myself working on tricky Lasius sp., which meant that I had to try to make sense of Seifert (1992). Seifert seems to be the Master of Morphometrics, in Europe at least, and the measurements and indices he uses are much more complicated than I had encountered up until that point. At first I really hated them. I couldn't understand why identification of Lasius needed to be so complicated - couldn't the species be better described and thus made easier to identify?

Over time morphometrics have grown on me and I've come to really appreciate them. I now even understand most of what Seifert does, though I will admit to being lost by some of the discriminants that he uses!

The most recent and one of the cleverest morphometric tools that I've encountered is from Seifert (2007), for separating the Formica picea/gagatoides/gagates group from the F. fusca/lemani group. I had already decided that the specimen that I was working on was F. fusca and knew that it definitely wasn't from the picea/gagatoides/gagates group, as these are all much shinier. However, in the couplet for separating the two groups I spotted an index that I had not encountered before: sqPDF.

Translating as best I can from the German, sqPDF is the square root of the distance between individual pubescence hairs within the triangle formed by the ocelli. PDF = l/n; where n = number of the pubescence hairs that intersect three transverse measuring lines of overall length l. The position of these measuring lines is shown in red in the picture below.


The thing that I found so intriguing about this is the pubescence hairs are extremely small, so I decided to see if I could make sqPDF work. I measured the length of the three lines combined to be 663µm and counted 68 hairs intersecting the three lines. This gave a PDF of 9.75µm, so the sqPDF was 3.12µm. This is within the range given for F. fusca/lemani (sqPDF 2.4-3.5µm) and outside of the range given for F. picea/gagatoides/gagates (spPDF 3.6-10.8µm), so the calculation worked!

This might seem like a lot of work, but it's not. Morphometrics are indisputable. I know from experience that you can get to the end of a key based on descriptions alone and be less than convinced that you've got the right answer. You then spend hours checking the other 'possibilities' had you taken different routes through the key. Morphometrics eliminate much of the doubt, give you a nice, neat, believable answer and ultimately save time.

If and when I finally write my first key, expect to see lots of numbers in the couplets!

Roy Snelling

It is with sadness that I report the death of Roy Snelling. Roy was one of the great figures in the study of Hymenoptera. He died in his sleep at the start of an expedition in Kenya.

I only had a small amount of contact with Roy, so I won't say too much. I met him on the Ant Course in Cairns, 2006 and had some email contact with him afterwards. He was a brilliant man with a wicked sense of humour, so I liked him right away, as I expect most people did.

He was also very generous with his expertise: he resolved the identity of some problem Rhoptromyrmex from Queensland and also provided some useful, and sometimes entertaining discussion on North American Lasius. His initial reaction to my query was, 'I detest Lasius!', a sentiment I suspect most people can sympathise with!

It is a sad loss, all the more so for his family and those close to him, to whom my thoughts go out.

Eulogies are at Myrmecos Blog and The Ant Farm and Myrmecology Forum.

Tapinoma simrothi subsp. festae

It was two months ago that I posted this image claiming it to be Tapinoma ambiguum. I was wrong - but that is nothing new!

Shortly after posting it I took the specimen to Cedric Collingwood, who glanced at it under a microscope and said 'Ah, it's festae!' Since then I've been planning to update this blog with a proper correction, but I wanted to be sure that I know why it is this species.

Why did it take so long? Basically, there is almost no information available on Tapinoma simrothi subsp. festae. It was described by Emery (1925), which I haven't been able to get hold of. I can find nothing else relating to it, aside from a mention in unchecked taxa in Agosti & Collingwood (1987). This entry has a question mark next to it, says that it's expected for the Balkan peninsula and the species is not featured in the key that followed.

Since I haven't encountered anything that clarifies the situation in the last two months, and forgot to ask Collingwood about it last time we spoke, I'm basing my acceptance of this identification on the fact that it is much larger than T. erraticum. T. ambiguum should be the same size as T. erraticum.

As far as I can make out, the size distiguishes T. simrothi from T. ambiguum and T. erraticum. T. simrothi subsp. festae is then distinguished by the shallow anteromedian clypeal notch, which is deeper than wide in T. simrothi. This makes me wonder whether it is the Tapinoma sp. mentioned in Collingwood & Agosti (1996), even though the scape index of this specimen is shorter at 97.

I expect that at some point T. simrothi subsp. festae will be raised to species status, as it seems to differ from T. simrothi no less than T. ambiguum does from T. erraticum.

Monomorium dakarense

I previously thought I had collected Monomorium dictator in the Gambia, as that is what this specimen keyed out as. However, I've been doing a lot of work on the salomonis-group recently and I no longer think that I was correct. I now think it is Monomorium dakarense.

It all boils down to couplet 36 of Bolton's (1987) key. I think it would be possible to debate for hours over whether the sculpture on the head of this specimen is 'uniformly densely reticulate-punctate' or 'with a silky, smeared or roughened appearance'. Initially I opted for the former because, well, it is reticulate-punctate, just more finely than the likes of Monomorium bicolor! However, I've since come to realise that this is what Bolton means by the latter, which leads to M. dakarense.

The difference between M. dakarense and M. dictator, other than the ambiguities of cephalic sculpture, seems to be size, number of ommatidia in the longest row and, importantly, scape index (SI). M. dakarense is overall the smaller of the two, with fewer ommatidia and a SI of 95-100, whereas M. dictator has a SI of 107-109. For those not familiar with SI, it is as follows:

Scape length × 100

Head width

The SI in this specimen is 92, putting it closest to the range given for M. dakarense. Given that Bolton only had the three syntype workers to measure it is likely that the true range of the SI includes 92. However, this is not the only difference between this specimen and the holotype, as the other measurements are (quoting the measurements for MJL143, followed by the range given by Bolton, in mm):

     Head length = 0.61 (0.57-0.59)
     Head width = 0.51 (0.44-0.47)
     Cephalic index (ratio of head width to height) = 84 (77-80)
     Scape length = 0.47 (0.44-0.45)
     Pronotal width = 0.31 (0.30-0.31)
     Mesosoma length = 0.72 (0.66-0.70)

Despite the larger size, the specimen is not big enough to be M. dictator and differs in the other features mentioned, so it is most likely M. dakarense.

It still remains a bit of a rediscovery. M. dakarense had been collected once in Senegal in 1914, so it's more likely than M. dictator, which had only been collected in Angola. The only specimens that I collected were found on the ground at Madiyana Camp on Jinack Island, and only at night. Since we stayed at Madiyana Camp for a few days it would be surprising if M. dakarense had been active during the day and I had not collected it then, which indicates pretty strongly that it is entirely nocturnal. Perhaps a combination of its nocturnal habits and its small size have meant that it has not been found again until now?

Camponotus vestitus subsp. intuens

I originally identified this as Camponotus cosmicus and wrote a nice long blog defending my decision to call it that. I even provisionally synonomised it with a few other species and subspecies. I was wrong!

At the time, I sent photographs to Brian Taylor, who replied, 'Why do you not think this is Camponotus vestitus?' Perhaps I should have recognised that his far greater experience was likely to lead to a correct identification, but I like to learn from my own mistakes.

C. cosmicus was one of the species that I checked when I visited the London Natural History Museum, as the holotype is there. C. cosmicus is a large and fairly stocky ant, even the minors, unlike my specimens. I was also able to check C. vestitus subsp. pectitus, which has all the right features (divergent pubescence on the gaster, same number of setae on the mesosoma, same propodeum shape) and differs only slightly in the colour of the head.

Arnold (1924) stated that Smith's (1858) description of C. cosmicus is useless, and it appears as though he is right. However, none of the authors who have written about C. cosmicus picked up on what I believe is probably the most significant characteristic, as all specimens in the museum had many erect setae on the ventral surface of the head. I can also add that C. cosmicus is predominantly very dark red (not black), with the propodeum rounding smoothly from the metanotal groove, less divergent pubescence on the gaster and a greater number of setae on the mesosoma.

So, maybe it is C. vestitus subsp. pectitus. It gets complicated because Bolton (1995) states that Santschi (1926) suggested that C. vestitus subsp. pectitus and C. vestitus subsp. intuens are the same, but at no point do they appear to have been properly synonymised. Reading Santschi's statement, it seems pretty clear that he has no doubt, so I can only assume that Bolton did not synonymise it because the description of C. vestitus subsp. pectitus post dates this statement! Forel's (1909) description of C. vestitus subsp. intuens is just as ambiguous as the descriptions of C. cosmicus and C. vestitus subsp. pectitus.

Update Nov 2008: My specimens have now been compared with the type specimens from the Naturhistorisches Museum Basel. This allowed me to confirm that they are very clearly C. vestitus subsp. intuens - a completely identical match. Possibly the colour of the head is the key feature in discriminating these subspecies.

I also showed my specimens to Cedric Collingwood, who claimed them to be C. jizani. This is a species from the Middle East, though he admitted that the only reason he named it thus was because he didn't know what else to call it! Possibly, C. jizani is a junior synonym of C. vestitus subsp. intuens or C. vestitus.

This species was collected a number of times only in the grounds of the hotel we were staying at in Kololi, Gambia. Here it could be found nesting in turret nests, so named because there were steep 'craters' of sand piled around the nest entrances, up to about an inch high. These are described by Arnold (op. cit.) for C. vestitus subsp. pectitus, which he states is rare and found nesting in sandy soils. He then describes,

'nest-entrances[s] surrounded by a circular, high and sharp-edged crater... This form of crater is distinctive of this insect.'

Corrections

Before I disappeared for Easter I visited the London Natural History Museum to compare my some of my Gambian specimens with ant specimens in their collection. As a result, I have a few changes to make, but need to do a bit more work before I make them. Until I change the posts, this will hopefully caution against relying on previous posts.

I had misidentified the following species:

• Camponotus cosmicus - more likely within what can best be described as the vestitus complex.
• Monomorium dolatu - doesn't appear to be any of the species included in Bolton (1987). I had suspected that this was the case, but without checking reference material went with the closest option.

I had correctly identified these species:

• Monomorium exiguum
• M. rosae
• M. osiridis
• M. vonatu
• M. egens
• Dorylus affinis

These species are perhaps open to debate, as I couldn't conclusively establish whether they were the same species or different:

• Camponotus rufoglaucus controversus - slight differences in setae and pubescence but the specimens checked were not types and were majors only.
• Camponotus olivieri lemma and delagoensis - I couldn't check these subspecies.
• Crematogaster impressa - the specimens present were collected by Donisthorpe and did not appear to be the same as mine or each other. Chances are this species and C. excisa will not be resolved until the taxonomy is revised.

Cataglyphis oasium

The size of an ant and how easy it is to identify are not necessarily related. Whilst Monomorium mictile, at just over 1 mm, was relatively easy to identify, I'd been pondering this very large species of Cataglyphis for weeks.

Cataglyphis is a genus that is taxonomically muddled. I've finally concluded that this species is probably Cataglyphis oasium. It was the keys in Santschi (1929) and Radchenko (1998) that eventually provided the most likely identification.

C. oasium was originally described by Santschi (1929), though the name he gave it (Cataglyphis bicolor st. nodus v. oasium) was invalid, so the authority for this species is Menozzi, 1932. Menozzi only gave two lines of text to the species, changing the name to Cataglyphis bicolor var. oasium, without noting that it was a new combination or providing a fresh description, and naming Santschi as the authority. The variety oasium was later given subspecies status and then species status by Radchenko (1997). Wehner, Wehner & Agosti (1994) suggested that C. bicolor subsp. oasium was synonymous with Cataglyphis savignyi, though they didn't actually synonomise the two names. Thus, the valid name is C. oasium. It's very confusing, so it took a little while just to sort out this history.

Information on the distribution of C. oasium is very sparse. Santschi mentions records from Tunisia and Algeria, whilst the most recent record that I'm aware of is Libya in 1931, which is reported by Menozzi. Radchenko (1998) states that it is found in North Africa and the Middle East.

This gives the impression that C. oasium is rare, but this seems unlikely. It is probably under-recorded due to the taxonomic difficulties. It is possible that the species collected by Lenoir and mentioned in The Ants of Africa is also this species. If C. oasium is found in oasis in the Sahara and in the Middle East it seems reasonable that it could also occur in The Gambia and Burkina Faso.

The Gambian specimens were collected from Kololi and Madiyana Camp on Jinack Island, mainly from sandy ground in scrub savannah. In this sort of hot scrub savannah it could be quite common, so it may be abundant further inland, away from the coastal breeze.

Slightly confused Monomorium egens

This specimen has proved difficult to identify, but I'm now pretty certain that I've got it right. It keys out pretty clearly as Monomorium egens using Bolton (1987), but is generally much more slender than the species that Bolton describes and has much longer scapes (SI 108).

Because it doesn't fit perfectly I've been puzzling over it for the past couple days. The resolution came when I translated Santschi's (1926) description of M. longiusculum from the French. This describes a slender species with scapes long enough to reach the posterior margin of the head (I've included my rough translation of Santschi's description below). This means that my specimen has slightly longer antennal scapes and may be more slender, but is probably close enough.

Bolton synonomised M. longiusculum with M. egens. What is strange is that he doesn't mention this level of variety despite having examined the type material for M. longiusculum, though he does confess not to be convinced that M. egens is a single species. Having now compared my specimens with those checked by Bolton in the Natural History Museum, London, I can understand why he decided to synonymise them, as there is no obvious difference other than the shape.

This species is another forest species from Abuko National Park in The Gambia, where it was collected from a tree. Bolton states that M. egens nests in rotten wood in the soil or in fallen trunks and forages in the wood and leaf litter. This seems to make finding it part way up a living tree trunk quite usual.

M. egens has been found in West Africa from Angola to Guinea, putting this specimen at the extreme northern edge of its known range.

The following is my translation (with a little help from Brian Taylor) of the type description for M. longiusculum from the French.

Monomoriumlongiusculum Santschi 1926

Worker. Length: 2.1 mm. Body brown, gaster brown-black. Appendages yellowish-brown. Funiculus yellowish. Smooth, shining. Slightly pilous. Pubescence suberect and more abundant on the scapes, adpressed and sparse on the legs.

Head approximately a quarter longer than broad, rather convex at the sides, the posterior margin straight with the angles rounded. Eyes two thirds as large as the space which separates them from the anterior margin of the head and placed between the middle and a third back from the anterior margin. Carina on the clypeus marked, not very divergent and little or not projecting at the anterior margin. Mandibles with 4 teeth. The scape reaches the posterior margin of the head. Articles 2 to 9 of the funiculus about as thick as long. Pronotum 'sub-shouldered', without a promesonotal suture and with the mesonotum in profile forming a regular and rather low convexity from the anterior to the metanotal groove. Propodeum longer than two thirds of the promesonotum and low, also convex, the sloping face not very distinct from the declivitous one; convex from one side to the other and narrow, width about half its length. Peduncle of the petiole as long as half of the base of the node; node triangular in profile and longer than high, not convex ventrally. Postpetiole a little shorter and lower than the petiole, roughly as high as long and rounded at the dorsally, as broad as long and a little broader than the petiole.

Tetraponera ambigua

My Tetraponera ambigua specimens have been the subject of some friendly debate, as Brian Taylor and I have been discussing them. I noted before that they have three ocelli, albeit reduced ones, but they have particularly wide postpetioles as well.

I've now conducted a very detailed investigation, including comparing the morphometrics of my specimens with Ward's (2006) measurements, and am convinced that they fall within Ward's broad definition. The ocelli number and postpetiole width (which Ward does not include in his paper) seems to add to the overall variability of this species.

There is probably still a chance that T. ambigua is a species complex, which is hinted at by Ward. Brian Taylor suggested 'Sima ambigua Em. r. erythraea v. occidentalis Stitz 1917' as a possible identity for my specimens, which has the broader postpetiole and similar overall appearance, but is more sparsely hairy and probably lacks ocelli. Nothing so far described seems to be a perfect match for what I've got.

I often find myself thinking that if organisms such as these occurred in Europe they would have been split into dozens of species, like Lasius, Myrmica, Formica, etc. Africa probably needs the attention of more taxonomists.

Blog Action Day

Since today is blog action day I've been racking my brain trying to think of something to write. To be honest, I've found myself thinking that I should have waited a couple days before creating this blog.

Why so hard? I guess it's too difficult to summarise the problem. Plus, as an ecologist, it would be nice to think I had an answer, but I don't.

What I've decided to do is focus on what I think are the three main threats to the environment:

1. Pollution.
2. Climate change.
3. Large-scale species extinction.

Worries about pollution have been around for about as long as civilisation I guess, but it still hasn't gone away. Fortunately, in the West at least, we're now pretty good at keeping on top of the problem - for every new pollutant we seem to be able to find a way of dealing with it, when enough money is thrown at it. We're even starting to think seriously about dealing with greenhouse gases, even though we don't know whether it's too late or not. If we're clever enough to create the problem we ought to be clever enough to fix it, though perhaps we need a little incentive first.

Climate change is probably the most prominent environmental catastrophes on the horizon. Obviously, this is caused by pollution, but I've listed it separately as it seems probable that eliminating pollution will not solve the problem of climate change on its own. Most evidence suggests that climate change is already upon us and will happen anyway. But let's not get too depressed: we've done some remarkable things throughout history and this problem is simply a matter of physics and chemistry. One imagines that it can be fixed, though there is very little incentive for governments to do this until it starts winning votes.

The third threat is the most serious of all. We've known for decades that we are responsible for one of the six major mass extinction events that this planet has ever experienced. The vectors for this are varied, and include pollution and climate change, as well as habitat destruction, population growth and exploitation.

I'm not convinced that we're doing much about it though. Sure, the panda's still with us and the tiger has just about managed to hang on (but who knows for how much longer). We've stopped whaling, nearly. We literally brought the Mauritius kestrel back from the brink. We perhaps feel that we've learnt from our experience with the dodo.

However, as with so many things, it is the little things that really matter - in this case 'the little things that run the world', to quote E.O. Wilson. Whilst we may feel like we do enough to protect the furred and the feathered, even the scaly and cold-blooded, we do ignore everything else. I'm not just talking about arthropods, but bacteria, viruses, fungi, etc., the things we know very little about.

'Well', you might ask, 'that's all very well, but what does it matter if we lose some of these things?' The problem is that we don't know at what point it will matter. We have named perhaps a tenth of all the species on the planet, and know precious little about that tenth. We don't know what will happen when one species, ten species, one hundred species are removed from an ecosystem, or what effect the changes to that ecosystem will have on us. We can see what effects losing entire ecosystems has though: increased flooding, extreme climate events and desertification to name a few.

Here's the key point though: when we've lost these species we're sure as hell not going to get them back!

'Ah', you say, 'but we can sample their DNA and bring them back from extinction once technology has moved on.' This is true, but to do this for every species, including those we do not know, would be an impossible task. Even if we were able to bring back every species alive today, we'd have no idea how to put the ecosystems they formed a part of and need to survive back together. Besides, our civilisation would need to survive long enough to do this. Quite frankly, we could ignore this mass extinction to the point where we realise: it's too late - we're screwed.

I've already mentioned him once: a few weeks back I found a video of E.O. Wilson talking about the same thing. He's much better informed than I am, so I strongly recommend it.

I'll leave the environmental solutions for another day, maybe.