Tuesday, 11 December 2007

Plagiolepis mediorufa

Plagiolepis mediorufa had only been recorded from the Congo and the Central African Republic, generally from myrmecophilous plants. My Gambian specimens were collected from plants, trees and a palm frond in Bijilo Forest Park, Kololi and Abuko National Park, Lamin, but nothing about the plants indicated that they were adapted to supporting ants. The Gambia also represents a significant range extension north and westwards.

The trouble is that I suspect there may be a few, as yet undescribed, small yellow and morphologically similar species of Plagiolepis in Africa as a whole. I have placed my specimens in P. mediorufa because it is currently the best fit, but would be interested to see where they are placed if the genus is ever reviewed.

The specimen that I photographed was sadly rather battered. Plagiolepis often tend to be rather soft and fragile, and so shrivel when they dry. Tapinoma does the same thing. (I think the funiculus of the antenna was missing when I collected it.) It was still the best of the three specimens that I had mounted.

Monday, 10 December 2007

Monomorium bicolor

Monomorium bicolor is an abundant ant in The Gambia. It had been collected there before in around 1926 in Banjul (formerly Bathurst), and in 2007 in Kololi and on Jinack Island. It is distributed from Angola north to Sudan and from Somalia across to Senegal.

M. bicolor seems to be present in a variety of habitats, as it was found on trees, on the ground in open areas, on buildings and once scavenging from a dead fish, but was only found nesting in the ground.

M. bicolor is very similar to Monomorium dictator, but differs by being generally larger, though also variable in size, and lacking abundant setae on the anterior half of the first gastral tergite. It should have at least two erect setae on the anterior margin of the first gastral tergite, but these were lacking in all Gambian specimens. Five out of the nine specimens examined had distinct pits where the setae should have been, but all lacked setae. Nevertheless, there is no doubt that they are M. bicolor, so the hairs have perhaps rubbed off or Bolton (1987) defined the species too narrowly.

Sunday, 9 December 2007

Death of a monarch

It's quite sad really. The queen of my Leptothorax acervorum colony has died. She was rather unceremoniously dumped at the far end of the foraging arena by the workers. It is possible that they have another queen. I can't check, as I cut the colony out in a piece of turf and, because they have been doing so well in there, left them alone.

I collected the colony earlier this year at Chevin Forest Park near Otley, West Yorkshire. In 2004 I collected a single dealate queen of Formica picea there, well outside of its established range. Despite frequent visits, no more F. picea have been found there. I went this year with Cedric Collingwood, who has helped me look for F. picea before, as we decided to make one last (unsuccessful) visit. The only good thing to come out of the trip was the L. acervorum colony.

Shortly after I got the L. acervorum home they produced an abundance of alate queens, but no males. Later they went into a period of inactivity when I started to wonder if they had all died, but then became active again a few weeks ago. Now that the queen has gone I'm wondering if the workers will produce any males, if there isn't another queen present.

I'd strongly recommend L. acervorum for anyone interested in keeping ants. They may be small, but they're kind of cute and very easy to look after. All they seem to need is a confined space with reasonable humidity and a steady supply of slightly crushed houseflies, which they hollow out. They will also drink sugar solution, but seem to prefer freshly-killed flies.

Monomorium osiridis

Monomorium osiridis had only been collected twice, in Kenya, before I picked up these specimens in The Gambia. It seems quite surprising to find M. osiridis on the other side of the continent, but I don't know what else these specimens could be.

M. osiridis and the southern African species Monomorium zulu and Monomorium rabirium are separated from other Monomorium by having 12-segmented antennae, smooth mandibles, conspicuous eyes, sculptured propodeum and no standing hairs on the dorsal mesosoma and gaster. M. osiridis differs from the other two by having a sculptured head, except for a median strip (visible in the bottom photograph).

I only collected M. osiridis once, on the ground at Madiyana Camp on Jinack Island. They were collected only at night, strongly indicating that they are entirely nocturnal, as may be the case with Monomorium dictator. This could be another instance of a species being under-recorded partly because it is nocturnal.

These have been compared with specimens checked by Bolton at the Natural History Museum, London, and are confirmed as M. osiridis.

Monday, 3 December 2007

Monomorium rosae

Monomorium rosae is a widely distributed species with a central African distribution that stretches from Kenya to Senegal. It was collected twice on Jinack Island in The Gambia, once on a tree and once in dry leaf litter at the base of a tree.

Bolton (1987) notes that this species varies in size and pilosity over its range, suggesting that M. rosae may contain more than one species. He distinguishes the species as currently defined as having 11-segmented antennae, dark colour, moderately long scapes and a distinctively shaped postpetiole.

It's interesting how many of the Monomorium now known from The Gambia have 11-segmented antennae. M. dolatu, M. exiguum, M. mictilis and M. rosae all have 11-segmented antennae, out of ten species recorded from The Gambia (40%). This contrasts with 12 species out of 149 listed by Bolton for Africa as a whole (8%). Maybe Monomorium with 11-segmented antennae are more common in this part of west Africa?

These have been compared with specimens checked by Bolton at the Natural History Museum, London, and are confirmed as M. rosae.

Sunday, 2 December 2007

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.

Sunday, 25 November 2007

Extreme myrmecology: Monomorium mictile

Monomorium mictile has to be the smallest ant I have ever found. It is very inconspicuous.

I started off with four specimens, but misplaced two before I could look at them properly (I still don't know how). I selected one of the two specimens to be mounted and, whilst I was getting everything ready, I brushed a bit of dust off my microscope stage. I knew what I had done as soon as I had done it - the bit of dust was the ant. It was no good looking for it on the floor, as it was gone.

This left me with just one, which had not died in a position that was conducive to mounting and I felt that trying to fix this would be too risky on such a small specimen. This is why the specimen in the photograph is not as well mounted as most others.

Bolton (1987) comments that material of this species is relatively scarce; it's not hard to see why!

M. mictile is widespread in Africa, found from South Africa north to Mali and Sudan. It as collected once in The Gambia from a tree in the coastal scrub on Jinack Island.

Monomorium exiguum

Monomorium exiguum has been found across central and southern Africa, from Ethiopia in the east to Guinea in the west and Zimbabwe in the south. It appears to be primarily a forest species, so it is no surprise that the Gambian specimens were collected from a tree in Abuko National Park, one of the few remaining patches of gallery forest.

Bolton (1987) states that M. exiguum as defined definitely contains more than one valid species, but could not resolve them. It is therefore interesting to note the small size of the Gambian specimens, which are apparently much smaller than is typical for the species; Bolton gives lengths of 1.5-1.7 mm whereas the Gambian specimens can be little more than 1 mm long.

These have been compared with specimens checked by Bolton at the Natural History Museum, London, and are confirmed as M. exiguum.

Wednesday, 21 November 2007

Monomorium vonatu

Yet another rediscovery. It gets too familiar after a while, but it does demonstrate how little is known about the ants of Africa.

Monomorium vonatu was known only from a single holotype specimen in the Natural History Museum, London. It was collected in 1970 in Ghana and described by Bolton (1987). It is easily distinguished from other species of Monomorium by the shape of the petiole and postpetiole, which both have distinct ridges running across them. The only other species that has this structure is Monomorium mirandum, which is very distinctly bicoloured.

As if to demonstrate that you don't need to go to great lengths to find interesting species, I collected my M. vonatu specimens in the grounds of the hotel we were staying in. They were found on the ground, either in bare sand or grassy areas.

Quite why this species hasn't been discovered anywhere else seems a bit of a mystery, as it was probably pretty common in suburban Kololi. Perhaps it is overlooked as another small black species of Monomorium.

These have been compared the holotype at the Natural History Museum, London, and are confirmed as M. vonatu.

Monday, 19 November 2007

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.

Saturday, 17 November 2007

Monomorium afrum

Monomorium afrum is the largest species in its genus found in the Gambia so far. It is very widespread in Africa, being from from South Africa to Sudan. The closest it has been found to The Gambia is the Ivory Coast, so this find represents an extension of its known range westwards.

It was found only once as a worker, running on the ground in the coastal resort of Kololi. Other species of Monomorium are much more common in The Gambia.

The sculpturation of the head and mesosoma is interesting, as it makes even in focus pictures appear out of focus. This reticulate-punctate sculpturation can be seen on the close up photograph of the head.

On the same day and in the same location as the M. afrum worker was found I collected a lone dealate queen. Queens away from colonies present problems for identification, as most have not been described. For this reason, I left the Monomorium queens that I collected until last (within the Monomorium at least). Fortunately, the queen of M. afrum has been described by Arnold (1926).

What's more, it is incredibly distinctive. In fact, when I first looked at it, I assumed that it was a Tetramorium, at least until I realised that it had the single unpaired seta projecting from the midpoint of the anterior clypeus typical of Monomorium and lacked the raised clypeal ridges of Tetramorium. It is the most peculiar Monomoroium that I have ever encountered.

My specimen seems to differ slightly from those described by Arnold. He describes the second and third abdominal segments of M. afrum queens being anteriorly smooth and shining. This presents a problem, as the second and third abdominal segment is the petiole and postpetiole. However, authors are sometimes unclear about this, so Arnold could have been referring to the second and third gastral segments (abdominal segments five and six). Despite this uncertainty, I can find no smooth and shining areas on any part of my specimen.

The queen of M. afrum is obviously very different from the worker. Arnold states that had he collected a specimen without the context of workers and other queens he would have considered it to be the type of an entirely new genus, and it's easy to understand why. Bolton (1987) comments that it shows modifications characteristic of socially parasitic species of Monomorium and may prove to be a temporary social parasite.

Wednesday, 14 November 2007

Tropical plants at the Eden Project

When the development of the Eden Project first started in Cornwall I made a prediction: that their biomes would become overrun with ants. This wasn't completely without precedent, as the this is exactly what had happened with Biosphere 2 with the crazy ant Paratrechina longicornis.

I'm rarely this accurate, so I'm feeling quite smug!

My first encounter with ants from the Eden Project was having a specimen thrust in front of me by Cedric Collingwood a few years ago. His explanation was that it had been brought to him by a friend who couldn't initially remember where he collected it, but quickly remembered when it became apparent that it was a tropical species. Since I hadn't encountered the species before I quickly forgot what it was.

Last year one of my colleagues brought me a specimen that he had collected from the tropical biome at the Eden Project (I like colleagues that bring me ants). This was clearly a Technomyrmex, probably T. albipes, but I really struggled to come to a satisfactory conclusion on which species it was, so made a note to visit the Eden Project to collect some more and hopefully make identification easier. I did this last Friday.

Within seconds of entering the tropical biome I had found ants. The biome is absolutely full of them. In one place they were so dense that with one puff on my pooter I collected about 40 specimens! Unfortunately, I only found one species: Technomyrmex. With the number that I collected I should be able to make a better species identification.

I've since had a chat with the person who deals with pest control at the Eden Project, Michael Pytel. He stated that they are T. albipes (I'm still going to check) and that they had actually declined in numbers over the past two years! Apparently they were not the only ant to have been introduced and actually displaced P. longicornis, the species that caused problems at Biosphere 2. Other ants that still occur include subterranean Pheidole and Hypoponera, and a species of Solenopsis has been found there in the past. Work will continue to try to reduce the Technomyrmex population and redress the balance.

T. abipes is a major pest species in the tropics. It would be easy to consider Technomyrmex only as a pest in the tropical biome, but I think it deserves a little more respect. Even if it escapes the biome it is very unlikely that it would become established, as the climate in the UK is too cold. It is probably the only contact with such a prominent tropical invertebrate that visitors to the Eden Project are likely to come across and so could be a valuable educational tool. They could demonstrate the global problem with species occurring in the wrong environment and the damage that they can cause to ecosystems. I'd like to see the Eden Project recognise this opportunity, if they have not already.

(Apologies to anyone who actually expected this to be about tropical plants!)

Tuesday, 6 November 2007

A froggy reprieve

It happens rarely. Every so often something happens that provides a glimmer of optimism for the conservation ecologist. This is probably one of those events.

I spotted the story a few days ago on the BBC News pages, but typically it took me a while to react. Apparently a team of researchers from the University of Otago have discovered a possible cure to chytridiomycosis in frogs. Frogs have been suffering serious declines worldwide due to a mystery disease and chytridiomycosis is one of the candidates for the cause. The researchers used chloramphenicol to cure animals of the disease in the lab.

Sadly, chloramphenicol has health implications in humans, so is unlikely to be used in a wider context. However it is very valuable progress. With continued research on this and other possibilities it might be possible to halt the decline and extinction of frogs and other amphibians.

Monday, 5 November 2007

Pachycondyla sennaarensis

Pachycondyla sennaarensis is probably one of the most common ant species in the coastal region of The Gambia, as I collected it 10 times. I also got to know it over the week that I was there and had soon started to ignore the many lone workers that I frequently saw.

Remarkably, given how common it is in the area that other myrmecologists were most likely to visit, it hadn't been recorded from The Gambia before. I'd be tempted to suggest that it might have spread into the country since the early 20th century, when the last myrmecologists visited, but it was recorded in Senegal at about that time. Perhaps it's just been more successful than other ants as the area has been developed.

It seemed equally happy around buildings and in natural areas, where it nested directly in the ground, often in cracks in concrete. It was described by Dejean & Lachaud (1994) as being at least partially seed eating, which is extremely unusual for a ponerine ant. My observations agree with this, as the refuse piles around nest entrances often contained seed husks and other vegetable matter.

They also showed the kind of wear on their teeth that other seed eaters, such as Messor, tend to develop on older workers. Rather typically, it proved impossible to get a decent photograph of the one specimen that showed really distinctive wear. I hope that the photos below give some indication of what I mean, despite the fact that they both chose to die chewing on their own legs.

The first one shows little wear:

Whilst the second shows slightly more (note particularly the tooth on the right just above the leg):

Perhaps you'll just have to take my word for it.

I also found a queen. This was washed up on the shore on the part of Jinack Island that is within Senegal, though it probably washed down the river Gambia to get there, as it was already dead. Despite the fact that it was not found in a colony, it has been possible to identify it as P. sennaarensis with some confidence, as none of the defining features are on the mesosoma and so are presumably the same on the queen as the worker.

This species also stings. I discovered this on my first day in The Gambia when, in my rush to get out and explore, I left my forceps and pooter in my case in the hotel. Picking up these with your fingers is perhaps not to be recommended! In terms pain, it wasn't actually too bad initially (I've been stung by worse), perhaps rating as a 2.5 on the Schmitt Sting Pain Index (just above a European honey bee). However, after 20 or so my thumb, in particular, was starting to feel a bit numb, so I decided to stop. For the next 3 days the skin on my thumb and forefinger, which had taken the bulk of the punishment, slowly peeled away.

All good fun.

Saturday, 3 November 2007

Nesomyrmex angulatus

Nesomyrmex angulatus is another widespread species, found from South Africa to Saudi Arabia. The closest it has previously been found to The Gambia is Ghana, so this represents another western range extension (along with Cataulacus traegaordhi). The key thing about this species that separates it from other Nesomyrmex is the very smooth profile of the mesosoma, coupled with the yellow colour.

Though I only found it twice, it's probably fairly common in more wooded parts of The Gambia. It tends to be pretty inconspicuous. I collected it from trees in Bijilo Forest Park and on Jinack Island, from coastal forest and scrub savannah respectively.

Tetramorium sericeiventre

Tetramorium sericeiventre is a very widespread species, occurring from South Africa north to Mali. A single worker had been collected in The Gambia in 1926, recorded as subsp. arenarium.

This species is not as common as some ants in The Gambia, but can be found in Kololi and on Jinack Island, where it can be quite conspicuous. It was collected from savannah, where it nested in the ground.

I was lucky enough to retrieve a queen from one of the nests, which is shown in one of the photographs.

Harmonia is overrated

Earlier this week I was in Dover, Kent and encountered my first harlequin ladybirds, Harmonia axyridis.

The surprising thing was that I hadn't already seen any. Since it first appeared in the UK in 2004 the species has spread at an incredible rate, and is now known from much of England and parts of Wales.

Because they are an invasive species that threaten the ladybirds native to the UK I collected as many as I could. On Thursday I took these into work not far from Bristol to show my colleagues what they should be looking out for, feeling a little smug that I could do this, until one of the people I work with, Jenna, mentioned that there were some in the window that were the same. She was absolutely right, they were harlequins as well.

As a result I scoured the office building, removing as many as I could find. This resulted in 28, to which I added a further 14 yesterday (Friday).

The question I guess I should ask myself, as an entomologist, is how did I miss these? The simple answer is complacency - I assumed that if they were in the area they would be pretty rare. Despite this I don't think we had any here last year, except perhaps for the odd one or two, so the speed at which they've become established is staggering.

I will continue to remove the ones that I find, but I think it's a lost cause. I think they're probably here to stay.

Sightings of the harlequin ladybird are being collected by the Harlequin Ladybird Survey, and can be submitted online.

Saturday, 27 October 2007

Cataulacus traegaordhi

This is the second Cataulacus collected from Abuko National Park in The Gambia (the other one was C. guineensis). I only managed to find one specimen of C. traegaordhi, so either it's less conspicuous, rarer or I just wasn't looking in the right places.

It has been found from South Africa north to Sudan, but apparently the closest it has been found to The Gambia is Ghana. Whilst finding C. guineensis in The Gambia apparently represented an northward extension of its known range, finding C. traegaordhi appears to have extended its known range westward.

Thursday, 25 October 2007

Cataulacus guineensis

At the risk of unintentionally starting a theme that could potentially be very restricting and uninteresting, I think I'm going to continue to post 'ant portraits'. Someone might actually find them useful.

This one is Cataulacus guineensis. It was collected Abuko National Park, one of the more famous protected areas in The Gambia. Abuko is a remnant of gallery forest, rather than rainforest. Despite its small size and the fact that we hired a guide (which for me meant that I didn't really have enough time to stop and collect ants), I still managed to pick up some species of interest.

Three of these, C. guineensis, Cataulacus traegaordhi and Pyramica maynei are proper forest species, so finding them in one of the few remaining pieces of proper forest in The Gambia was quite satisfying.

C. guineensis has been found in the Republic of Guinea, as might be expected from its name, and throughout west Africa, but not from Senegal or further north, so this find from The Gambia may represent the northern limits of its known range.

Monday, 22 October 2007

Gambian ant list

My long-running, rather ambitious, spare-time project at the moment is to produce a synopsis of the ants of The Gambia, as very little is known about its ant fauna. This started off from collections made by myself in 2007, from which I still have a lot of unidentified Pheidole minors, but it seems unlikely that I will be able to identify these accurately. All parts of this list are open to change, as there are very few species where I think my identifications are indisputable.

The existing list of ants of The Gambia was part of the Ants of Africa website, with a few additional species included in a checklist produced by Emms and Barnett. In combination these lists included just 21 species.

I've also borrowed some ants from Oxford University Museum of Natural History, so I will be adding the genera and species included in this collection over the next few months, as they are identified. I would be very interested to hear of any other ant specimens collected from the Gambia.

The key to the resources used is as follows:

* = collected during this survey in 2007.
T = listed by Taylor.
E&B = listed by Emms and Barnett.
OUMNH = specimens in the collection at Oxford University Museum of Natural History, collected by D. J. Mann in 1997.
NB = specimens in the Collingwood collection, all collected by Nicolas Blacker.

          rotundatus subsp. guineensis*
          luteum* (OUMNH)
          melanocephalum* 1
          atriceps (T)
          attenuatus (T)
          rufescens (T)
          affinis* (T)
          fimbriatus (T; OUMNH)
          fulvus (OUMNH)
          fulvus subsp. glabratus (T)
          maculatus* (T)
          olivieri subsp. delagoensis*
          olivieri cf. subsp. lemma?*
          rufoglaucus cf. subsp. controversus?*
          sericeus* (T; E&B; OUMNH)
          vestitus subsp. intuens*
          vividus* (T; NB): pseudogyne in Collingwood collection.
          lividus (NB): unlikely, as it is not found elsewhere in Africa.
          oasium* (NB)
          capensis subsp. guineensis* (OUMNH)
          capensis subsp. laevis* (OUMNH)
          longinoda* (T; E&B)
          E&B also list smaragdina, but this is probably erroneous.
          nigrita (OUMNH)
          emeryi*: a widespread tramp species.
          chiarinii subsp. taediosa (T)
          cf. excisa*
          gambiensis* (T)
          cf. impressa*
          impressa subsp. brazzai (T)
          wellmani (T)
          bicolor* (T; OUMNH)
          edouardi (OUMNH) 2
          sericeiventre* (T)
          brunoi (T)
          escherichi (NB)
          tarsata* (E&B)

1 See: Wetterer, J. K. 2008. Worldwide spread of the ghost ant Tapinoma melanocephalum (Hymenoptera: Formicidae). Myrmecological News 12: 23-33.
2 Queen only. Quite clearly either T. edouardi or T. tersum, but matches the description of the queen of T. edourdi better than T. tersum (= kivuense).

Sunday, 21 October 2007

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.

Saturday, 20 October 2007

Limonium britannicum subsp. celticum

On Thursday I was lucky enough to have the opportunity to visit Hilbre Island in the Dee Estuary and saw hundreds of plants of the rock sea-lavender Limonium britannicum subsp. celticum. This would be the third rarest plant I've ever seen, but there's a problem.

L. britannicum subsp. celticum is listed in Stace (1997) as endemic to the coast from Anglesey to Westmorland. Because of this it has been considered rare and important, and was a UK Biodiversity Action Plan (BAP) species. The UKBAP has undergone a lengthy review process, the results of which were recently published. One of the changes was the removal of L. britannicum because of a taxonomic review. It's also on the 'waiting list' of the The Vascular Plant Red Data List for Great Britain for the same reason.

The only trouble is, I've been unable to find out what taxonomic changes to Limonium have occurred, as the review doesn't appear to have actually been published yet. Thanks to BioImages I know that it was discussed at a conference, but can't find any actual details. I've checked everywhere I can think of to find evidence of the review, but even the 2007 BSBI plant list shows the Limonium binervosum agg. unchanged.

As a result, this subspecies seems to be in a bit of a limbo at the moment. Presumably the people who made the decision to remove it from the UKBAP know the results of the review, even if it hasn't been published yet. Those of us who are out of the loop will presumably have to wait until then and hope that the uncertainty doesn't influence the level of threat to these plants.

From my point of view it is an even bigger deal, as it affects my 'list of the rarest plants that I've found'! For the moment I will construct it with the existing Limonium taxonomy, as follows:
  1. Ophrys aveyronensis (limited to one valley in the Causse du Larsac, France).
  2. Limonium recurvum subsp. pseudotranswallianum (limited to the coast of Co. Claire, Ireland).
  3. Limonium britannicum subsp. celticum.
  4. Ophrys aymoninii (limited to the Causse region in France).
When the Limonium review is published I may end up having to completely revise this, but I have no idea which is the next rarest plant that I've found. Maybe I'll have to try and live without a list?

Monday, 15 October 2007

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.

Sunday, 14 October 2007

It begins... Plus Tetraponera claveaui

I've decided to start a blog. I'm not entirely sure why.

I've decided that this is going to be mostly about ants, as these are what I spend most of my spare time studying. Mostly this is taxonomy, but I hope as things progress it will move into other subject areas as well. There will probably be the occasional general ecology posting as well, as that's what I do for a living.

To start the ball rolling: I appear to have rediscovered Tetraponera claveaui. This species was first collected in Senegal around 1913. It was described by Santschi and appears not to have been found since. I collected about 7 workers from an Acacia pod in The Gambia.

Brian Taylor has produced a photomontage from my images for his online guide to the ants of Africa, but my attempt is shown here.

I also collected T. ambigua in The Gambia, which is a much more widespread species in Africa. It seems to be incredibly variable, but some of my specimens appeared to have three ocelli, which is not included in the variability described by Ward (2006).