Welcome

Welcome to my blog

This is where I post various musings about wildlife and ecology, observations of interesting species (often invertebrates)
and bits of research that grab my attention. As well as blogging, I undertake professional ecological & wildlife surveys
covering invertebrates, plants, birds, reptiles, amphibians and some mammals, plus habitat assessment and management
advice
. I don't work on planning applications/for developers. The pages on the right will tell you more about my work,
main interests and key projects, and you can follow my academic work here.

Monday, 28 March 2011

What's in a bee-friendly garden?

After a few fairly technical posts lately (taxonomy and the like), I thought it was time for something a little less cerebral i.e. watching bees and seeing which garden plants are important food sources in spring.

I've seen a few bee species already this year (inlcuding a few yet to be identified), but one that has stood out by spending a lot of time in our garden is the Hairy-footed Flower Bee Anthophora plumipes. Being about the size of a bumblebee, these are quite distinctive and show considerable sexual dimorphism. The males have yellowish-brown hairs and a pale yellow face, while the females are black apart from orange hind femora (which can be hidden). Since a single male appeared on 13th March, I've seen the level of activity increase, firstly with the arrival of a second male and then a couple of females. Most of their feeding has been on Lungwort - they have been seen investigating other flowers such as the ornamental Quince, but this does not seem popular and is regularly spurned. I wondered if it was a nectar-poor cultivar, but today I saw a different bee species (maybe an Osmia) feeding from it. Hopefully I'll be able to add more species photos, but they don't stay still for long...


A. plumipes male on Lungwort
A. plumipes female approaching Lungwort - mmmm, tasty...
 Curious to know what other plants are important (to make sure the garden is bee-friendly), I tracked a few individuals and found a female actively investigating our small clump of Snakeshead Fritillaries. Only one is fully open and she spent some time in this flower before trying the other 'unripe' flowers and heading back to the Lungwort. All Fritillary pollination is welcome as the tiny clump is part of our 'wild meadow' area and it would be great if it could spread naturally.

A. plumipes female approaching Fritillary flower
Thinking about sorts of habitat beesd and other invertebrates require in a garden, I've been considering inlcuding a small bare sandy patch. It would be interesting to see if a sand-nesting wasp might appear, though I expect it'll be popular with the ants... However, bare soil - even in small patches - is used by all sorts of species, including the Andrena bee (possibly A. barbilabris, I'm not sure yet) below - seen investigating small bare patches on a south-facing bank in the local churchyard. These I believe are known to use compacted patches of soil such as on footpaths, and the bank is certainly quite well packed and warm. Along with the investigative behaviour, the amount of tussling between individuals suggested (to me at least) that either territories in the form of suitable soil patches were subject of competition, or possibly it was the locations of yet-to-emerge females (males emerge first). I'm hoping to get good shots of more species - hopefully identified - and come up with more ideas to attract pollinators, but until then, enjoy the photos so far!
 
Andrena sp. showing plenty of white fluff plus white bands on the abdomen.

Andrena sp. investigating bare soil - is that a burrow?

Friday, 25 March 2011

Resident weevil...

A couple of days ago my wife brought in a weevil that she had found perched on washing in our garden (most domestic!), and wondered if I knew what it was. It looked familiar and looked like something quite common, but got me thinking about the identification and recording of common invertebrates. After all, many of them look very similar and can't be accurately identified from a straightforward inspection, even with a hand lens. This means that the less common species may well be under-recorded if the assumption is that the specimen is the more common of various initial possibilities. So, I thought I'd go through the process of identifying a small invertebrate, in this case the captured weevil.

The first thing to mention is literature - often books, sometimes online resources such as interactive keys - because without these, identification of many species with any certainty is difficult or more likely impossible. Personally I tend to buy what I can find/afford and borrow the rest (e.g. from biological records centres, museums, inter-library loans and so on). There is, for me anyway, great joy to be had in building up a good references library. Anyhow, onto the specimen - looking yellower than in reality due to lighting...

Dorsal view (approx 5mm long, excluding legs & antennae)
Ventral view
Now, the first stop (unless you already know which family/subfamily it's in) is Morris (1991) and the key to main groups of weevils. The first step's easy - it has elbowed antennae with a long first segment. Then onto the rostrum; it's short and this could cause confusion sending the identification towards Platypodidae and Scolytidae (which it isn't), but the tibiae are smooth on the outer edge, the thorax doesn't have borders and is also clearly narrower than the front of the elytra - so, it's in the Curculionidae ('true weevils'). Now for a closer look to get to subfamily...

Underside of the head
Side view of the head showing curved scrobes (dark antennal sockets in front of the eyes)
Scales on the elytra - pale and flat
Looking at the scrobes (middle pic), they can't be seen clearly from above, are narrow, and don't point in a direction passing through the middle of the eyes - so, not Otiorhynchinae. There's no clear fringe of hairs along the sides of the front edge of the thorax - so, not Tanymecinae. The elytra together are about twice as long as wide, and the upper surface has pale scales forming stripes on them - these features mean it is in the subfamily Sitoninae, now known as the Tribe Sitonini within the subfamily Entiminae (Duff 2008). It also mean it's time to leave Morris (1991) and move onto Morris (1997) which has keys to tribe, genus and species levels (and can also be used to key from Curculionidae to Sitonini, taking a slightly different route looking at tarsal claws).

Though Duff (2008) includes several genera within the Sitonini, Morris (1997) keys them to species but considers them all to be within the genus Sitona - mentioned just to add a little taxonomic confusion to the mix. Anyhow, keying onwards...

The scutellum has no upright tufts of scales and has a rostrum about as long as wide. So, not S. griseus. The elytra have flat scale and no upright bristles; the dorsal surface has a striped (rather than tesselated) pattern and is scaled rather than pubescent - the overall appearance is brownish rather than black. The head is also more-or-less flat between the eyes (rather than being deeply dented) and the upper edges of the eyes are not obviously higher than the top of the head. OK so far, but it now gets a little trickier.

I can't see the median furrow on top of the head very clearly, but it does broaden out and reach further back than the midpoint of the eyes, ending without a clear pit. So, not the scarce S. puncticollis. Also, the elytra are more than 1.5 times as long as wide, and more-or-less straight-sided, and the scales are oval but not 3-4 times as long as broad (more like 2 times), so it isn't the common S. lepidus. The eyes are clearly convex rather than almost flat which leaves just two species - S. cylindricollis and S. lineatus. The separation is straightforward enough here - in S. lineatus the pronotum is widest behind the middle, and slightly narrower at the base than at the front (as here) and also has complete elytral stripes rather than just short segments as would be seen in S. cylindricollis. So, this is an overwintering adult of S. lineatus just emerged in the spring - widespread and abundant in lowlands, fully winged, and known to feed on pea and bean leaves in gardens and allotments as well as on vetches. Eggs are laid by these overwintered adults with larvae feeding on root nodules and the next generation adult by about July in the south, August in the north. So, I suppose it could be seen as a pest, but a few leaf-holes won't matter and so it has been released back into the garden. I fully expect to find more...

References

Duff, A.G. (ed.) (2008). Checklist of Beetles of the British Isles. A.G. Duff, Wells.
Morris, M.G. (1991). Weevils. Richmond, Slough. [Naturalists' Handbook no. 16; an excellent introduction]
Morris, M.G. (1997). Broad-nosed weevils. Coleoptera: Curculionidae (Entiminae). Handbooks for the Identification of British Insects 5(17a): 1-106. [Royal Entomological Society; a bit more advanced]

Tuesday, 22 March 2011

Ants round my home, woodlice in theirs...

My entomological side is getting twitchy - after months of near-invertebrateless cold, I can see a variety of multi-appendaged beasts crawling, flying and generally being busy. So, during a trip to dig the allotment, I couldn't help noticing quite a bit of ant activity. They haven't found the house (i.e. the kitchen) yet but are busily working in the garden, around all kinds of cracks and various bits and pieces. As I left through the back gate, there were even some that had helpfully started work at head height (in and around two bolt-holes in a gatepost) allowing me to look at them closely without crouching down: most thoughtful...

Black ants busy around a hole in a gatepost.
Looking more closely, it seemed as if they were clearing out the remains of previous occupants - there looked to be bits of woodlouse and spider coming out. Closer still, building work was going on with 'cement' plates being formed inside the hole - luckily I managed to capture one ant placing a mouthful (mandible-ful?) of building material...

Note on the left - one ant placing building material
They look like one of the common dark garden species, but it's always worth checking so I brought a couple indoors to see if I could key them out (using Skinner & Allen 1996). The single-segment waist with well-developed petiole (a little plate sticking up from the waist), circular spiracle towards the rear of the propodeum (segment just in front of the waist) and a lack of rows of bristles on the underside of the hind tibia brought me to the genus Lasius (not unexpectedly...). From there, various features including the presence of standing hairs on the antennal scape and hind tibia (but not the double rows seen in other groups) took me to the common species L. niger.

Hind tibia with standing hairs
Head, including antennal scape with standing hairs (see below the eye)
OK, so I've been distracted - time to dig the allotment and off I go... digging (finally) takes place and I'm almost finished when I notice (a) some orange-yellow ants and with them (b) some tiny white woodlice. This looks straightforward enough - the ant is Lasius flavus nesting in the grassy path and the woodlouse is the Ant Woodlouse Platyarthrus hoffmannseggi.

L. flavus and P. hoffmannseggi - both around 3-4mm long
P. hoffmannseggi - the yellow colour is just due to lighting/image processing...
P. hoffmannseggi is an interesting beast - it is white (in the top photo you can just see dark gut contents through its dorsal surface), blind and lives closely associated with ants of almost any species (Hopkin 1991), often found in their nests where it may feed on pellets regurgitated by the hosts (Williams & Franks 1988) and/or may be a more general scavenger in the 'rubbish-dump' parts of nests (Pontin 2005). It has also been noted as following lines of ants when nests have moved (Donisthorpe 1927). This is unusual behaviour for a woodlouse (it is the only myrmecophilous - 'ant-associated' - woodlouse in Britain), but not unique - in Malaysia there is a species of Exalloniscus which 'hitchhikes' (maybe 'stows away' is more accurate) on the pupae of ponerine army ants. Although not often seen without digging, it is fairly common in southern England and Wales, becoming scarcer northwards (will climate change extend its range, and if so, how does it disperse?). Beyond this, little is known about P. hoffmannseggi - an area for a keen researcher to work in maybe?

References

Donisthorpe, H. St. J. K. (1927). The Guests of British Ants.Routledge, London. [interesting if you can find it, but can be expensive]
Hopkin, S. (1991). A key to the woodlice of Britain and Ireland. Field Studies 7(4): 599-650. [this has also be published in separate reprint form]
Pontin, J. (2005). Ants of Surrey. Surrey Wildlife Trust, Woking. [another volume in the excellent series of Surrey atlases]
Skinner, G. J. & Allen, G. W. (1996). Ants. Richmond, Slough. [excellent keys to British species]
Williams, T. & Franks, N. R. (1988). Population size and growth rate, sex ratio and behaviour in the ant isopod Platyarthrus hoffmannseggi. Journal of Zoology 215: 703-717.

Wednesday, 16 March 2011

Things that tell me spring has sprung

OK, not the most difficult thing to work out - after all, there are daffodils and crocuses everywhere - but it's still interesting to look a little more closely. For example, a couple of days ago among the daffodils (various cultivars of Narcissus sp.), was one flower that stood out...

Summer Snowflake Lucojum aestivum ssp pulchellum
These are taller and more robust than Snowdrops (Galanthus nivalis) and have the green spots you can see above. The native form (ssp aestivum) is found occasionally in damp places in Britain, particularly the south. They are separated from ssp aestivum by this having minute teeth along the stem-edges, at least near the base, while in ssp pulchellum (the cultivated variety) the stem edges are smooth. Here, no teeth = pulchellum. There's also the very rare (a few sites in Dorset and Somerset) Spring Snowflake L. vernum, and their flowering periods overlap, but L. vernum has only 3 stamens and a clearly bilobed spathe. As L. vernum usually has a solitary flower (sometimes 2) and L. aestivum usually has 3-7 (sometimes 1 or 2), I did have to check...

L. aestivum showing stamens - more than 3
Stem showing smooth edges
Another sign of spring is of course the presence of bumblebees - they can be found at almost any time of year, but their activity (along with that of some other charismatic insects such as bee-flies, the Bombyliidae) does herald warmer things to come. So, when something bumblebee-esque flew past, I wasn't too surprised, but it didn't look quite right. Having followed it to its destination, a clump of flowering Lungwort (Pulmonaria officinalis), I managed to get the following shot of it feeding:

Male Anthophora plumipes feeding on Lungwort
Unfortunately it wasn't keen on staying still to have its photo taken, so I couldn't get a shot of the tarsal bristles, but this does appear to be a Hairy-footed Flower Bee Anthophora plumipes, and a male going by its pale 'mask'. This is a species known to fly from around mid-March so this is not unusually early, but as far as I know L. aestivum has generally been considered to flower from April. As is often the case with such observations, it's anecdotal, but I have to wonder if this is just one of the many natural phenomena that indicate an earlier spring start linked to climate change and the higher average temperatures now clearly seen. Certainly, more thorough analysis of phenomenological data suggests spring starts maybe 3 weeks earlier than it did several decades ago. If I have a spare moment (maybe longer than a moment...) I may have to look at the data on NBN to see if the earliest records by year have changed for either of these species...

Further reading

For bees in the south of England:

Baldock, D.W. (2008). Bees of Surrey. Surrey Wildlife Trust, Woking.

Equally excellent, and by the same author/publisher is 2010's Wasps of Surrey.

Wednesday, 9 March 2011

Entomology of Star Wars. Episode III: Bears in Space

Right, here it is - the third and final instalment of 'The Entomology of Star Wars' (unlike George Lucas I will not be tempted to produce a shiny but unsatisfying second trilogy). Following on from Episode II (exogorths - giant asteroid-dwelling worms), this time I decided to focus on the 'mynocks', the parasitic space-dwelling organisms that attach themselves to spacecraft to feed off their energy (they can feed on electrical, electromagnetic and stellar energy, and so may attach themselves to structures such as power cables or 'ion ports'), absorbing it through the suctorial mouth located between their eye stalks. They can also feed on the material of the hull, causing damage or even destruction; in turn they are eaten by exogorths and may survive for some time, flying around inside the worm's gut until finally digested.

A mynock attached to the Millennium Falcon, showing its leech-like sucker. Nice.
A little light reading ensures me that mynocks are silicon-based and fatally allergic to helium (they swell and die); also they lack any major organs and so reproduce by binary fission once they have fed sufficiently. Apparently, there have been other species (or subspecies), including one that had a normal mouth (rather than a sucker), and another that gave birth to live young. They do however have bat-like wings which they can use when in an atmosphere. So, what parallels can be drawn between the mynock and real-world organisms?

Firstly, as I've mentioned before, I'm not going to look at ideas surrounding non carbon-based life - there are plenty of bloggers looking at this already. Similarly, although mynocks can feed on ship hulls, I covered chemosynthesis and the mineral metabolism in Episode II. So, let's start with the most obvious aspect of mynock life (to me anyway) - their ability to survive in the vacuum of space. Although there are no known vacuum-dwelling real-world organisms, there is one experimental example which a lot of regular science readers may well be aware of - the tardigrade. For those who don't already know about this, here goes:

Tardigrades (Phylum Tardigrada) are microscopic to just-visible (adults range from 0.1 to 1.5mm) aquatic segmented animals with eight legs, sometimes known as 'water bears' or 'moss piglets'. They are well known for their ability to survive exceptionally hostile conditions, often more so than any other animal. Tardigrades are able to survive in extreme environments that would kill almost any other animal. Some have survived temperatures down to near absolute zero, up to approx 150°C and about a thousand times as much radiation as other animals, not to mention almost a decade without water. How do they manage this?

Tardigrade - a (tiny) bear in space!


Well, along with some other groups of organisms which can survive essentially complete dehydration, tardigrades accumulate large amounts of disaccharides ('double sugars' i.e. those with two molecular rings), especially sucrose and trehalose (Crowe et al. 1998). It appears that these sugars stabilise membranes and proteins when dehydrated, probably by hydrogen-bonding to polar residues in the dry macromolecular assemblages. This maintains dry proteins and membranes in a state similar to that seen when wet. It has been suggested that, as sucrose and trehalose form a glassy state when dry, glass formation (vitrification) is sufficient to stabilise dry biomaterials - however, Crowe et al. (1998) showed that both direct stabilisation and vitrification are required and that trehalose has properties linked to its crystal structure than may aid the stability and longevity of dehydration-tolerant organisms that contain it

Meanwhile, Jönsson et al. (2005) exposed tardigrades to high levels of gamma radiation. Without going into the results in detail, tardigrades do eventually die and/or become sterile, but the study concluded that their radiation tolerance may be due to currently unknown, but efficient, DNA repair mechanisms (unlike the  biochemical protection seen for their dessication tolerance). Then, in September 2007, tardigrades were taken into low Earth orbit on the FOTON-M3 mission and exposed to either the vacuum of space or both vacuum and cosmic/solar radiation. Despite these hostile conditions, where vacuum causes severe dehydration, while cosmic/solar radiation (with an unfiltered UV component) would be expected to cause considerable genetic damage. However, upon their return to Earth, many had survived and even laid eggs that hatched normally - they are the first animals to survive such exposure (Jönsson et al. 2008).So, they can protect their cells membranes and either protect and/or repair their DNA well enough to not only survive in space, but reproduce afterwards - our first parallel with mynocks, up to a point at least, but are there any others?

Well, I'm fairly sure there are no direct energy feeders (discounting photosynthesis of course!), unless you include the 'mystic woo' of psychic healing etc. Which I don't. However, the binary fission of a large organism is interesting - generally this is associated with small organisms such as Protozoa and Algae. However, it is also seen in some Myxomycetes ('slime moulds', but not Fungi). These are often soil micro-organisms, but in some species a single-celled, but multinucleate, 'plasmodium' is formed which is the final feeding stage, engulfing many kinds of small food items. Although essentially a single cell, these can be large - one example of Brefeldia maxima in North Wales can cover whole stumps, be a centimetre thick over a square metre and weigh up to around 20kg - possibly the largest cell known (Ing 1999), and its certainly feasible that such a structure could divide. So, we have our 2nd real-world parallel.

So, lastly on to the helium allergy... well, helium poisoning certainly can occur (e.g. if overused for 'squeaky voice' purposes), but although there's a general feeling of 'you can be allergic to anything', I've not been able to find anything about genuine helium allergies. It is pretty unreactive, and I suspect at least some of the anecdotal reports I found are actually allergies to the material the helium was held in (balloon rubber, latex glove powder etc). S, although a major anaphylactic event might parallel the effect of helium on mynocks, this remains an unproven 'maybe', and as Meat Loaf said, 'two out of three ain't bad'.

With that, I shall end my 'Entomology of Star Wars' trilogy, but fear not fellow invertebrate-SF nerds - I am starting to form ideas about B-movies and Iain M. Banks novels...

References

Crowe, J.H., Carpenter, J.F. & Crowe, L.M. (1998). The role of vitrification in anhydrobiosis. Annual Review of Physiology 60: 73-103.

Ing, B. (1999). The Myxomycetes of Britain and Ireland. Richmond, Slough.

Jönsson, K.I., Harms-Ringdahl, M. & Torudd, J. (2005). Radiation tolerance in the eutardigrade Richtersius coronifer. International Journal of Radiation Biology 81(9): 649-56.

Jönsson, K.I., Rabbow, E., Schill, R.O., Harms-Ringdahl, M. & Rettberg, P. (2008). Tardigrades survive exposure to space in low Earth orbit. Current Biology 18(17): R729-R731.

Thursday, 3 March 2011

Altica carinthiaca: moving with climate change, or simply overlooked?

Altica carinthiaca Weise 1888 is a small (3-4mm) leaf beetle (Coleoptera: Chrysomelidae) widespread but scattered the western Palaearctic from Britain to Baikal, mainly in northern European countries; in more southerly locations it is associated with montane and submontane habitats. It was only recognised as a British species in 2000 (Cox 2000) having been confused with A. palustris and A. pusilla var. montana, although re-examination of collections has found British specimens dating back to 1939. An excellent photograph of a male, including aedeagus, can be found here.

Although not considered threatened in Britain, it is generally considered rare across its range as a whole although known from a range of habitats. The British host plant is the Meadow Vetchling Lathyrus pratensis, while in continental Europe it is also known from other plants such as Knotgrass Polygonum aviculare, Salad Burnet Sanguisorba minor and Speedwells Veronica sp. (Borowiec & Scibior 2008).

Following re-evaluation of old specimens, a British distribution map could be created which, as in Cox (2007), indicates a southern and eastern English distribution.


However, in February 2011, the species was discovered during suction-sampling in Cheshire, well north of its accepted distribution (see the red cross on the map). In recent years it has also increased its range in Finland (Kangas & Rutanen 1993), and been found for the first time in Poland (Borowiec & Scibior 2008).

In Poland, the previous lack of records could simply be due to the species having been overlooked, and the authors consider this to be the case due to previous problems with identification. However, although this has clearly also occurred elsewhere (e.g. Britain), a genuine change in distribution can not be discounted. As a species associated with higher latitudes (or higher altitudes at lower latitudes), it is certainly a species which might be expected to have its range affected by the increasing temperatures caused by climate change. The difficulty is of course that any perceived northerly (or higher-altitude) shift in distribution could be due to the species having been previously overlooked in these areas - without a well understood 'initial' distribution it is difficult to isolate temperature/climate effects. However, the re-evaluation of British specimens did not find any more northerly locations, so the map above (current in 2007 apart from the Cheshire record) may well be an accurate representation of the species' British range at that time. So, what does the Cheshire record tell us? Well, apart from the fact that A. carinthiaca is now present in Cheshire, not necessarily much - it is after all only one record - but if other northerly locations are found, it may reveal a shift in the species' northern boundary. Certainly, with taxonomic and identification problems now having been tackled (at least to some extent), it is hoped that more records of this species will appear so that changes in range, if any, can be identified as has been the case with more 'charismatic' species such as the Long-winged Conehead Conocephalus discolor and the Wasp Spider Argiope bruennichi which have expanded their ranges in Britain, while montane/high-latitude species such as the Ptarmigan Lagopus mutus appear to be being squeezed out as their range disappears. As for A. carinthiaca, and many other species, time, and hopefully good data, will tell.

References

Borowiec, L., & Scibior, R. (2008). Altica carinthiaca (WEISE, 1888) (Coleoptera, Chrysomelidae) - species
new to the Polish fauna. Polish Journal of Entomology, 77 (4), 305-308 Other: ark:/13960/t56d64f8s


Cox, M.L. (2000). Progress report on the Bruchidae/Chrysomelidae Recording Scheme. The Coleopterist 9(2): 65-74.

Cox, M.L. (2007). Atlas of the Seed and Leaf Beetles of Britain and Ireland. Pisces, Newbury.

Kangas, E. & Rutanen, I. (1993). Identification of females of the Finnish species of Altica Müller (Coleoptera, Chrysomelidae). Entomologica Fennica 4: 115-129.

Tuesday, 1 March 2011

When conservation fragments fail - the demise of the Pashford Pot Beetle

Much is written about connecting protected areas with the aim of achieving landscape-scale nature conservation, and the problems of isolation, fragmentation, edge effects and so on in small, disconnected sites are well known, even if some of the mechanisms involved are not fully understood (e.g. Harris 1988, Murcia 1995). There are many examples of areas where species and areas of 'protected' habitat have suffered through a lack of connectivity, both in terms of the landscape itself and the policies and legislation covering them. In Britain, one particular example, the Pashford Pot Beetle Cryptocephalus exiguus, illustrates this issue especially clearly at the national (UK) level.

C. exiguus, photo © Lech Borowiec


C. exiguus is a widespread Palaearctic species (in Mongolia and Korea it is known as ssp. amiculus), but in Britain has only been recorded in few scattered sites, mainly in eastern England. Between 1898 and 1954 it was recorded from Freshney Bog, Lincolnshire, but since then it has been known only from a single site - Pashford Poors Fen, Suffolk - with the most recent record from 2000.


NBN map of C. exiguus distribution
Pashford Poors Fen is a SSSI (Site of Special Scientific Interest) and a nature reserve managed by the Suffolk Wildlife Trust. Covering 11.3 hectares, it is known for its mosaic of drier grassland and wetter fen areas, both of which support a range of interesting plant and animal species. It is however essentially an ecological island within a sea of intensive land use (mainly agriculture). C. exiguus itself is listed as 'Endangered' (RBD 1) and is covered by the UK Biodiversity Action Plan (BAP). It is a wetland species associated with mixed fen and fen meadow, and although little is known about its biology in Britain, it is believed to feed on Common Sorrel (Rumex acetosa), among other possibile host plants. Targeted survey efforts found small numbers during the 1980s and 90s and concluded that the habitat had degraded to such an extent that it could only support a small population, if any. Although the BAP set a target in 1995 of maintaining the population, and if possible enhancing it with a view to translocating it to other sites, it has not been found since 2000 and BAP reporting in 2005 simply stated 'Target not Achieved'. Given that the species was listed as Endangered in the 1980s and subsequently BAP listed, and the site is a nature reserve designated as a SSSI and managed well by a conservation body, what has happened?

Essentially, this is where the landscape issue comes in. Fojt (1994) noted that fens and their vegetation communities (many of which are localised, some of which are rare, and all of which are of high conservation value) are dependent on calcareous spring water, but that they are threatened by drainage (e.g. for agriculture). Many fens have been damaged by drainage, and although this has been occurring for a long time,  spring-dependent communities have often survived. However, more recently there has been increased abstraction of aquifer water, and this fundmentally threatens the ecological functioning of fens both directly and by worsening the effects of droughts (which may well increase in frequency and severity as a result of climate change). Fojt's report notes that changes had already occurred in the species composition of many sites, in some cases changing the type of vegetation community. This of course has knock-on effects on species, such as invertebrates, which rely on particular plant communities. Fojt also notes that groundwater abstraction directly threatens springs and their associated (and nationally important) plant communities although in most cases, the lack of intensive hydrological study makes it difficult to determine the precise impacts of groundwater abstraction on fen water tables. Looking at solutions, Fojt noted that,

"The problem of dehydration due to water abstraction needs to be tackled strategically in the long term, though action needs to be taken over currently existing licences. The alleviation of the problem will be helped if water resource plans accommodate the water demand of those fens with a high wildlife interest."

As with many sites, this true of Pashford Poors Fen which is both small and surrounded by land use which is effectively, through water abstraction and drainage, hostile to its continued well-being, even if unintentionally. In the 1990s, the Suffolk Local BAP stated that action included extension of the SSSI boundary in 1996 to improve control over adjacent drainage ditches, and the installation of additional bunds to attempt to retain higher water levels during the summer. The management plan for the site was rewritten with greater emphasis on the vegetation management of those areas where C. exiguus had been found, focusing on providing an appropriate grazing regime during autumn and early winter. A Water Level Management Plan was mooted to deal with issues relating to control of water resources on the site, but for fens in general these have tended to be inadequate as they do not cover groundwater or water quality.

So, what has happened? Well, no-one knows for certain, but it is likely that C. exiguus is at best extremely rare in Britain, possibly extinct. Of course, it might be rediscovered at Pashford Poors Fen, or indeed at another site. At the Palaearctic scale, it could be argued that this isn't too important - it was rare and localised in Britain even when land management was at least a bit more sustainable (i.e. in the 19th century), and remains widespread elsewhere. However, aside from the intrinsic value of any species as a contributor to national and local biodiversity (and I consider this important in itself), it highlights a major failing in conservation. The site and species were both listed/designated and therefore, in principle at least, protected. The problem had been identified, and required action understood - indeed, as site managers, the Suffolk Wildlife Trust did what they could. Yet, the site has still degraded and the species has probably been lost. Why? Well, it's simply because conservation requirements remain politically a lower priority than many other competing interests. In this case, water abstraction licences for agriculture were granted despite the impact on adjacent wildlife habitat, and regardless of the site's conservation designation and status. This could have been taken into account but wasn't - and so, the fate of the site and species was taken out of the hands of the Wildlife Trust: by the time favourable changes started to be made in policy etc, it was already too late. Still, hopefully the relevant lessons will have been learned...

I could go on about the Government's continued failure to protect Britain's biodiversity (Countdown 2010 anyone...), but - at least for now - I won't. However, this is hardly a unique situation - a recent post by Ted McRae at Beetles in the Bush covers a parallel issue from Missouri - and it seems that, unless conservation requirements become fully integrated and suitably weighted in decision-making and land management/planning processes, it is something that will continue to occur. Still, not all is doom and gloom - since I took over as organiser of the UK Chrysomelid Recording Scheme, two more chrysomelids have been found - Longitarsus symphyti which should be a definite addition to the list, and Smaragdina salicina which is so far known only from a single specimen.

References

Fojt, W.J. (1994). Dehydration and the threat to East Anglian fens, England. Biological Conservation 69(2): 163-175.

Harris, L.D. (1988). Edge Effects and Conservation of Biotic Diversity. Conservation Biology 2(4): 330-332.

Murcia, C. (1995). Edge effects in fragmented forests: implications for conservation. Trends in Ecology and  Evolution 10(2): 58-62.