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THE BUMBLEBEES OF SUFFOLK ADRIAN KNOWLES Abstract All the species of bumblebee known to have occurred in Suffolk are discussed in terms of their historical and present distribution. Conservation priorities are discussed, along with possible future trends in bumblebee populations. Introduction Bumblebees are, on the whole, one of the more “accessible” groups of invertebrates as far as the general public and naturalists alike are concerned. Keen gardeners and those with an interest in natural history can immediately recognise several different forms and can probably hazard a name at some. They are furry enough to appear “cute” rather than dangerous, like the social wasps, and are therefore viewed with affection rather than fear. However, their study is a more difficult task than one might first suspect. Two of the most common species, the Buff-tailed Bumblebee Bombus terrestris and the White-tailed Bumblebee Bombus lucorum, have workers that can be indistinguishable. The Red-tailed Bumblebee Bombus lapidarius has TWO other look-alikes. Some Suffolk species are no longer with us in the county; some not even in the country. Others have made a recent arrival. The aim of this paper is to summarise these comings and goings, to highlight the conservation needs of some species and to encourage the recording and study of these appealing insects. This is not the place to go into matters concerning life histories in detail. Suffice to say, most UK bumblebees have a social structure led by a queen who rears large numbers of workers, who then help to run the nest. Towards the end of the colony’s life, males and new queens are reared, which mate where after the new queens over-winter before founding new colonies the following year. Some bumblebees, however, are classed as “cuckoos” or, more scientifically, “inquilines”. These queens take over the nests of their host, often killing the host queen. The cuckoo queen then lays eggs, the young of which are raised by the host workers, believing them to be their siblings. The only sexually active bumblebee queens and males that emerge from such a nest are those of the cuckoo species. Cuckoo bumblebees used to be placed within the genus (first part of the Latin binomial) Psithyrus, but they have recently been placed back with their social hosts within the genus Bombus. This is, in some respects, unfortunate since the distinction in their lifestyles is paralleled in differences in their anatomy and lifecycle (there are no workers of the six inquiline species), which are a big aid to their identification. Having them in a separate genus reinforced these differences. Where common English names have a long-standing and largely universal acceptance I refer to them, as above. However, if you’ve never heard of “Barbut’s Cuckoo-bee” you might as well start off knowing it by the name Bombus barbutellus. If you find scientific names a little daunting one can do no better than to re-iterate an observation of Mike Edwards and Martin Jenner in their excellent bumblebee book (see Aids to Further Study). They point out that no child has a problem with the name Tyrannosaurus rex – it’s an infamous dinosaur but it’s still a Latin binomial they are using to name it!
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The species accounts below have been arranged in alphabetical order, rather than by normal taxonomic grouping. It is hopefully an aid to study and easy reference to find ruderarius next to ruderatus rather than several pages away just because they belong to a different sub-genus. In analysing the historical distribution of these species, I have relied on two key works: Claude Morley’s The Hymenoptera of Suffolk published in 1899 and a summary of the bee fauna of Suffolk, again by Morley, which appeared in the 1936 Transactions of the Suffolk Naturalists’ Society (Volume 3). Where thought useful, I have included the synonyms by which Morley and other workers of his day would have called the species, to aid interpretation of his notebooks and other contemporary works. Modern data have come from a number of sources. Other than personal observation of the author, a small number of local naturalists have submitted records to the Society or to national recording schemes. I am particularly indebted to Heather Paxman, who has over recent years sent me many records and detailed notes of her observations whilst visiting numerous gardens and on walks in south-east Suffolk. Paul Lee and his students at Flatford Mill have made a number of significant discoveries, whilst, in the west, Adrian Parr has also made some useful observations. Others have made useful contributions and their names are noted in the appropriate species account. Additional data have been gleaned from records held by the Bees, Wasps and Ants Recording Society (BWARS), which can be viewed via their own web site (www.BWARS.com) or via the National Biodiversity Network (www.nbn.org.uk). Two external consultants have made significant contributions to the Hymenoptera records of the county: Mike Edwards, notably surveying the RSPB’s land around Minsmere; and Steven Falk, who undertook a comprehensive survey of the Center Parcs holiday complex at Elveden for several years. Species Accounts Bombus barbutellus (Kirby, 1802) Synonymy Morley (1899, 1936): Psithyrus barbutellus Kirby This is one of the six species of “cuckoo bumblebee” that take over the nests of the true social bumblebees, being referred to as inquilines. The host of Bombus barbutellus is the very common Small Garden Bumblebee Bombus hortorum, although B. barbutellus is nowhere near as common as its host. In the UK B. barbutellus is reasonably widespread across England, but very sparsely recorded in Wales, Scotland and Ireland. The earlier of Morley’s two main works (1899) only cite references from other authors (Kirby, Perkins and Tuck) which tends to suggest that he was himself unfamiliar with the species. The cited locations are scattered across the county, suggesting a widespread, if thinly spread, distribution. By the time of the 1936 Transactions, Morley rather dismissively describes it as “constantly seen”. However, modern records are distinctly sparse. It is one of the more variable and cryptically marked species, making the taking of specimens desirable to confirm identity, and this deters some bumblebee observers from pursuing identification further. Modern records are thinly scattered across the county and doubtless many more localities for this species remain to be discovered.
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Figure 1. Bombus barbutellus 1980pre-1980 0
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Figure 2. Bombus bohemicus
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Bombus bohemicus (Seidl, 1837) This is another cuckoo species, attacking the nests of the very common Whitetailed Bumblebee Bombus lucorum. Although national distribution maps show it to be found throughout the UK, it is in fact a distinctly northern species, with southern localities being rather localised. Within East Anglia it has been recorded quite widely in Norfolk, from coastal habitats and the Brecks, but in Suffolk it is seemingly restricted to the extreme north-west, in Breckland. Steven Falk recorded it quite regularly during the period 1994–2004 from the Center Parcs complex at Elveden, but the other four known localities are the result of isolated observations. This species was not mentioned in either of Morley’s works. This is likely to be either because of his lack of visits to its Suffolk stronghold in the Brecks or due to confusion with other, similar species. (See Fig. 2 over page) Bombus campestris (Panzer, 1800) Synonymy Morley (1899, 1936): Psithyrus campestris Panzer This is another cuckoo species, this time attacking the nests of the Common Carder Bee Bombus pascuorum and possibly other carder bees (which are extremely rare in Suffolk). Although found throughout the UK, it is most widespread towards the south, although nowhere could it be described as common. In his 1899 treatise, Morley states “I have never yet seen it alive”, but by the time of the 1936 Transactions it was “constantly seen”. Rather than suggesting a notable increase in the distribution of this species, it is more likely that Morley is commenting on his greater experience in later years, although over-exaggeration of its status should not be ruled out.
Modern records are concentrated in those two parts of the county that have been most heavily recorded: Breckland in the north-west and in the south-east. Bombus cullumanus (Kirby, 1802) Always a rare bee, this species has now, beyond reasonable doubt, become extinct in the UK having been last seen in 1941 (Edwards and Roy, 2009). It is also declining dramatically across Europe. In 1899, Morley only cites Kirby’s record from Witnesham north of Ipswich, published in 1802. However, in the 1936 Transactions he makes additional reference to a male taken at Barton Mills. However, this appears to be an error. Morley notes that the details of this record were published in Entomologist’s Monthly Magazine in 1923, but this paper relates to the bumblebee having been recorded at Barton Hills to the north of Luton in Bedfordshire. Edwards and Roy (2009) note that the bee was always associated with extensive, species-rich calcareous grassland (as is Barton Hills), but this does not seemingly fit its Witnesham location, regarding geology.
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Figure 3. Bombus campestris 1980pre-1980 0
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Figure 4. Bombus cullumanus
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Bombus distinguendus Morawitz, F., 1869 Synonymy Morley (1899): Bombus latreillellus var. distinguendus This species was formerly considered to be a variety of what we now call B. subterraneus. Although always a rather scarce and localised bee, B. distinguendus was known from all parts of the UK, including Suffolk. Since then, it has undergone a significant decline, so that it is currently only known from the Inner and Outer Hebrides, Orkney and the north coast of mainland Scotland. It is a UK Biodiversity Action Plan (BAP) species. Morley’s only specific reference to it was in his 1899 work, where he noted a handful of localities, albeit scattered widely across the county: Barham, Lowestoft, Tostock, Southwold and Brandon. There can be little doubt that it has been lost to the county for the foreseeable future. Bombus hortorum Linnaeus, 1761 The Small Garden Bumblebee Bombus hortorum is one of the more widespread species in the UK, although more sparingly recorded in upland areas. Between Morley’s two main works, his estimation of this bumblebee declined from “common” to “widely distributed, but rather local”. Today, it is a widely recorded species in Suffolk, across all geological zones and landscapes, although inevitably likely to be more restricted in the agricultural clay lands of the central zone. 1980pre-1980 0
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Bombus humilis Illiger, 1806 Synonymy Morley (1899, 1936): B. venustus Sm. The Brown-banded Carder Bee Bombus humilis was considered to be extinct in Suffolk until recently. Nationally, it was formerly known from scattered localities across England and Wales (e.g. IBRA/ITE 1980), but since then it has undergone a drastic decline and hence its identification as a UK Biodiversity Action Plan (BAP) Priority Species. Its core distribution today is along the south Wales coast, the south-west peninsula, Salisbury Plain, coastal localities in Kent and south Essex, including extensive brownfield habitats. Morley (1899) cautiously referred to records from Lowestoft, Tostock (“not very common”), Brandon (“widely distributed) and Ipswich, where he described it as “common”. In the 1936 Transactions it did not merit any site qualification, being dismissed as “ubiquitous”, which seems a bold statement, even given its formerly widespread status. Edwards and Telfer (2002) show no Suffolk records at all and only a single coastal record for Norfolk. Then, in 2005, Mike Edwards recorded the species on Westleton Walks whilst undertaking contract survey work for the RSPB. This was followed in 2006 by an observation of this species by Heather Paxman at Bawdsey in the south-east of the county. Given the lack of general Hymenoptera recording in Suffolk, these records might be of long-standing but only recently discovered populations, but recent colonisation also cannot be ruled out. In recent years, B. humilis has spread in Essex from its main populations along the Thames Estuary corridor to several sites scattered up the coast and into the North Essex Vice County. 1980pre-1980 0
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Figure 6. Bombus humilis
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Bombus hypnorum (Linnaeus, 1758) The Tree Bumblebee, as it has come to be known, is a recent colonist of the UK, being first recorded in 2001 near Southampton (Plate 5). Since then it has spread quite dramatically across England and Wales, seemingly occupying a niche in open woodlands and gardens not utilised by native species. This arrival and spread is being viewed as a natural phenomenon, possibly driven by climate change, rather than an “invasion” by an alien, exotic species (as is the case with, for example, the Harlequin Ladybird). It is occasionally being reported nesting in box eaves and other roof structures high off the ground, mimicking its more normal tendency to nest in cavities in trees. The earliest Suffolk record of which I am aware comes from July 2007, when Tim Strudwick observed the species at the RSPB’s Lakenheath Fen reserve in the far north-west of the county. Then, in 2008, Alison Thornhill recorded a specimen at the Flatford Mill study centre whilst on a Field Studies Council course. Since then there have been numerous records across the county, so that it is now known from Sudbury to Hollesley in the south to Breckland and Lowestoft in the north. The continued spread of this species across the UK is being actively mapped by the Bees, Wasps and Ants Recording Society (BWARS), who would gratefully receive all records of this species (as would your Society’s Hymenoptera Recorder!), even from districts when the bee is already known to occur. 1980pre-1980 0
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Figure 7. Bombus hypnorum
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Bombus jonellus (Kirby, 1802) This is another species with which Morley did not appear to be familiar. In 1899 he cites Kirby’s 1802 observation that it was rare around Barham but also noted that Morice (no date) considered it to be abundant on heathers near Lowestoft. These two observations are repeated without additional comment in the 1936 Transactions. Nationally, it is at its most widespread across the moors of Scotland, favouring foraging on heather flowers (Plate 6) as it does throughout its range. However, it is also thinly scattered over northern England and Wales, and quite widespread over the southern heaths of Sussex, Surrey and Hampshire and also the south-west peninsula. It is therefore slightly surprising that it is largely un-recorded from East Anglia and has seemingly never been recorded from the formerly ample heaths of Breckland. This situation may be in part due to under-recording since to the casual observer it bears a close resemblance to the very common Small Garden Bumblebee Bombus hortorum. The first modern record for this small bumblebee comes from 1997, when Mike Edwards recorded it from Walberswick and, in subsequent years, from Minsmere, Aldringham Walks and North Warren. In 2001, Paul Lee recorded B. jonellus from near Bawdsey in the extreme south-east – the first modern record away from this central Sandlings stronghold.
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Figure 8. Bombus jonellus
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Bombus lapidarius (Linnaeus, 1758) This species, the Red-tailed bumblebee, has probably always been one of the more common species in Suffolk. It has been recorded right across the county, including the generally less diverse central clay lands; a situation no doubt assisted by its exploitation of gardens, road verges and churchyards as foraging habitat. 1980pre-1980 0
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Figure 9. Bombus lapidarius Bombus lucorum (Linnaeus, 1761) Synonymy Morley (1899): Bombus terrestris var. lucorum The previously held opinion that this species, the White-tailed Bumblebee, was no more than a variety of Bombus terrestris limits comment on its former distribution but it is assumed that both it and B. terrestris were widely distributed and common. In his 1899 work, Morley described Bombus terrestris var. lucorum as “apparently common�. It warrants no comment at all in his 1936 summary. Today it is widespread across the county, although records are sparse in the particularly under-recorded central clay lands.
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Figure 10. Bombus lucorum. 1980pre-1980 0
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Figure 11. Bombus muscorum
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Bombus muscorum (Linnaeus, 1758) Synonymy Morley (1899, 1936): B. Smithianus White This bumblebee, known as the Moss Carder Bee, has declined significantly across Suffolk, in keeping with the national trend. It is more widespread in the northern half of the UK, whilst in the south it has seemingly been lost from most of its inland stations, including Breckland, so that it is here a species of coastal marshes, seawalls and dunes. It is now another UK BAP species. Morley (1899) described it as “widely distributed” and “to be taken in the Brandon District in numbers by anyone with sufficient time at their disposal”. By the time of the 1936 Transactions, he summarised it as ubiquitous, which is surely an over-exaggeration, since this is not backed up by the known records. There are four modern localities, although it is felt likely that it will occur elsewhere along the coastal zone. In 1992, Peter Yeo observed it at Walberswick, followed by a record from Aldringham Walks in 1998 by Peter Harvey. More recently, the author took specimens at Felixstowe Ferry (2006) and Falkenham Creek (in 2009). See map Fig. 11. Bombus pascuorum (Scopoli, 1763) Synonymy Morley (1899, 1936): B. agrorum Fab. Morley (1899) described the distribution enigmatically as “Nayland etc., very common” and “ubiquitous” by the time of the 1936 Transactions. It remains a common species throughout the county, including the central clay lands. 1980pre-1980 0
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Bombus pratorum (Linnaeus, 1761) The Early Bumblebee was, during Morley’s time a common and widespread species. Whilst still widespread in the county, it is encountered rather less frequently than some of the other common species. 1980pre-1980 0
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Figure 13. Bombus pratorum Bombus ruderarius (MĂźller, 1776) Synonymy Morley (1899, 1936): B. derhamellus Kirby This small bumblebee has undergone a dramatic decline in recent decades, falling victim more than other species to the loss of extensive, flower-rich grasslands in our countryside. As a result, it has been recently added to the list of UK Priority BAP species. Nationally, it was formerly thinly widespread across England and Wales and reasonably common in East Anglia and the south-east. Since then it has undergone a decline in distribution extent and abundance within its range. In both1899 and 1936, Morley implied that it was found widely in Breckland but was rare elsewhere. This is still very much the case today. Steven Falk recorded the species at Center Parcs, Elveden, several times between 1994 and 2004, with other records coming from Beck Row, Icklingham and Maidscross Hill. In the north-east there is a solitary record from near Sotterley, recorded by Heather Paxman in 2007. In the south-east, Paul Lee and his FSC students have recorded it at Tattingstone and Sutton, whilst Ted Benton recorded it within urban Ipswich in 2009, on vegetation bordering the River Gipping.
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Figure 14. Bombus ruderarius Although probably genuinely rare in Suffolk, it is likely that this species remains under-recorded on account of being mistaken for the extremely similar B. lapidarius. Both species have black workers with orange/red “tails� (the hind segments of the abdomen) and the character cited in books regarding hair colour on the hind tibia is often obscured by pollen. The best character to separate the two species – the shape of the tip of the middle leg tibia usually requires microscopic study and hence a specimen taken, which will often deter the casual observer. Bombus ruderatus (Fabricius, 1775) Synonymy Morley (1899): Bombus hortorum var. subterraneus and var. harisellus Morley (1936): This species is not mentioned and so presumably aggregated with B. hortorum records. To Morley and his contemporaries, the Large Garden Bumblebee was no more than a variety of B. hortorum and so seems to have attracted little attention. Early taxonomy and identification has been confused by the existence of all black colour forms of both B. ruderatus AND B. hortorum. The all black B. ruderatus (Plate 7) is probably what was intended under the name hortorum var. harisellus, but this name may also hide some records of the much less common black variant of what we now call B. hortorum. Bombus hortorum var. subterraneus is the typical three yellow band B. ruderatus. In 1899, Morley noted one observation of nests at Tostock, the details of which were published in Entomologists Monthly Magazine.
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Figure 15. Bombus ruderatus The 1980 IBRA/ITE Atlas shows that this was, even then, a rather localised English bumblebee in decline and that decline continued to the point where its extinction within the UK was feared. As a result, the species was included within the UK Biodiversity Action Plan for urgent conservation action. In recent years an increase in the number of records either indicates an upturn in its fortunes or that Hymenopterists are doing better at finding and identifying it. There are now modern records for Maidscross Hill at Lakenheath and nearby at Icklingham in Breckland. The only recent record away from this region was an observation by Heather Paxman in 1993 in Woodbridge. Bombus rupestris (Fabricius, 1793) Synonymy Morley (1899, 1936): Psithyrus rupestris Fabricius Morley (1899) cites localities dotted across much of the county. In the 1936 Transactions summary he describes it as “constantly seen”. This apparent abundance is hard to believe, given the species’ general scarcity across the whole country. It is another species that has declined dramatically since before the 1960s and is now accorded the status of Nationally Scarce. The 1980 IBRA/ITE Atlas indicates a thin scatter of records across Breckland and old records for the Ipswich area. It is one of the “cuckoo” species and one that may well suffer from under-recording on account of its superficial resemblance (Plate 8) to its host, the Red-tailed Bumblebee B. lapidarius. There are only four modern records: Barrow in West Suffolk (Adrian Parr, 2007); Woodbridge (Heather Paxman, 1994); Holywells Park, Ipswich (Adrian Knowles, 2010) and Monks Eleigh (Arthur Watchman, 2009).
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Figure 16. Bombus rupestris Bombus soroeensis (Fabricius, 1777) Synonymy Morley (1899, 1936): B. soroensis, Fab. The stronghold of this small bumblebee is now the northern half of Scotland, with additional records from northern England, Wales, the West Country and Salisbury Plain. Formerly it was also known from thinly scattered locations across central and eastern England but it appears to have virtually disappeared from this part of the UK. Morley repeats two sightings, neither or which are his own: around Ipswich (recorded by Rothney) and at Barton Mills in the far north-west (observed by Perkins). There are no other records for this species in Suffolk and, if the UK trend is anything to go by, there is currently little prospect for it being re-found here. Bombus subterraneus (Linnaeus, 1761) Synonymy Morley (1899, 1936): B. Latreillellus, Kirby Even in 1899, Morley described this species as “the rarest of our local Bombi�. It appears to have been thinly scattered across Breckland and surrounding districts, with other records from Lowestoft, Ipswich, Barham and Tostock. Sadly, this is another species no longer recorded in Suffolk and, worse still, in the UK. The last known record was from Dungeness in 1988 and this species is now considered to be extinct in the UK. It is listed in the UK BAP Priority species schedule and there are currently plans to re-introduce it to the UK from English stock that was taken to New Zealand many years ago.
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Figure 18. Bombus subterraneus
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Bombus sylvarum (Linnaeus, 1761) This is another species no longer known from Suffolk, but here the prospects are perhaps a little more encouraging. The Shrill Carder Bee (Plate 9) is another UK Biodiversity Action Plan (BAP) species, following a dramatic decline in its fortunes across the UK. From being thinly scattered across southern England and Wales, it has declined over the last 50 years to a few clustered meta-populations along the south Wales coast, Somerset Levels, Salisbury Plain and the margins of the outer Thames Estuary in Kent and Essex. In Morley’s day it appeared to be not uncommon in Breckland, the heaths around Ipswich, and elsewhere across Suffolk, although one would again have to question his 1936 Transactions summary of “abundant everywhere”. In recent years this species has been moving north within Essex from its main centre along the Thames estuary up the coast, typically associated with flower-rich seawalls and coastal grazing marshes. There is therefore hope yet that this species might recolonise Suffolk if this trend continues. 1980pre-1980 0
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Fi Bombus sylvestris (Lepeletier, 1833) Synonymy Morley (1899, 1936): Psithyrus quadricolor, Lep. This cuckoo-bee primarily attacks the nests of Bombus pratorum. Morley considered it to be “the least common of its genus”, although that accolade should probably have been given to P. bohemicus, of which Morley was seemingly unaware in the county. Although recorded throughout Britain, and
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quite common and widespread in southern England, this bee is rather scarce in East Anglia. Modern records are thinly scattered across most of the county, with the exception of the central north, where it has not yet been recorded. 1980pre-1980 0
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Figure 20. Bombus sylvestris Bombus terrestris (Linnaeus, 1758) This is one of the most common bumblebees in lowland Britain, and especially England. It is one of the earliest to be recorded each year, with the large buff-tailed queens giving it its English name. Workers have white “tails” and can be indistinguishable from the White-tailed Bumblebee, Bombus lucorum. For this reason, B. lucorum was long considered to be no more than a variety of B. terrestris. This might rather blurs the known historical distribution of the two species, but there is little doubt that both were very common in Morley’s day. The Buff-tailed Bumblebee remains a very common bumblebee in Suffolk, with the paucity of records from the centre of the county being down more to lack of recording effort than it is to real scarcity there. (see Fig. 21 overleaf). Bombus vestalis (Geoffroy in Fourcroy, 1785) Synonymy Morley (1899, 1936): Psithyrus vestalis, Fourc. This cuckoo bee attacks the nests of B. terrestris, and is similarly coloured in order to aid the invasion of the nest. In the 1936 Transactions, Morley thought it sufficiently common to not warrant mentioning specific locations. It is, today, probably even more common than then, with an apparent northward expansion of it range within the UK. (see Fig. 22 overleaf).
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Figure 22. Bombus vestalis
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Discussion In all, 27 species of bumblebee have, at one time or another, been recorded within Great Britain. Of these, 23 have been recorded within Suffolk. The missing four are: Bombus pomorum, recorded only fleetingly from Deal in Kent for a short period during the 19th Century; B. monticola, which has always had a distinctly northern distribution; B. magnus and B. cryptarum. The last two species have been much debated in recent years, being considered by many to be no more than races or varieties of the White-tailed Bumblebee, B. lucorum. However, recent DNA analysis has supported the names being granted full species status. Because of this uncertain status, both species are likely to be widely under-recorded although early indications are that they are both rather northern species, with very rare records from the south and southeast. It is therefore conceivable that one or other of these species might be recorded within the county. Of the 23 recorded species, 18 are currently known to occur within the county. The five that have been lost to us are: Bombus cullumanus Bombus distinguendus Bombus soroeensis Bombus sylvarum Bombus subterraneus
extinct in the UK national retreat in distribution to extreme north and north-west of Scotland national retreat in UK distribution to the north and west. drastic national decline but some signs of range expansion northwards from south Essex populations. extinct in the UK; subject to re-introduction programme.
From this, it can be seen that the loss of these species appears to be due to the general malaise that has affected the British countryside over the last 50 years, rather than any specific phenomenon that can be attributed to Suffolk alone. Of the 24 species of bumblebee currently known in Britain, seven are included within the UK’s Biodiversity Action Plan Priority Species list. That nearly one third of an invertebrate group is of conservation concern says much about the state of our countryside in recent years. Those species that have been lost or undergone a dramatic decline are known to favour extensive areas of flower-rich grassland as foraging habitat and it is the very widespread loss of this habitat in our intensive agricultural landscape that is likely to be the cause of this decline. As such, the bio-diverse landscape of Breckland is likely to be of great importance to the conservation of some species in Suffolk. Bombus bohemicus is only known in Suffolk from here, whilst B. ruderarius and B. ruderatus appear to have their strongholds in the north-west. The coastal Sandlings and open marshes of the coastal zone also have an important role to play, with B. humilis and B. jonellus only recorded from here. If its trend in Essex is to continue, B. sylvarum might also eventually recolonise this coastal zone. Recent studies are starting to indicate that even quite modest changes in our farming landscape can have a positive impact on our bumblebee fauna.
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Suffolk Natural History, Vol. 47
Extensive areas of only moderately species-rich grasslands can support bumblebees if the flora includes good quantities of clovers, other legumes, early flowering plants such as White Dead-nettle and a few late flowering species, such as Common Knapweed (Centaurea nigra agg.). Such habitat can be provided by means of headland strips adjacent to hedgerows or the artificial, earthen seawalls that protect much of our coastline. Conservation headlands within an otherwise agricultural landscape can aid all sorts of wildlife and help breath life back into parts of the countryside where grassland is at a premium. This philosophy is at the heart of the Suffolk Wildlife Trusts’ “Living Landscapes” initiative and was embraced by the Society’s own “Linking Landscapes” conference in October 2011. The Future What then does the future bring for Suffolk’s bumblebee? One thing that is almost certain is that the Tree Bumblebee B. hypnorum will continue to spread across the UK and become more widespread and common in Suffolk. This species has truly conquered England in the ten years it has been in the country and is here to stay. There are signs that the populations of some of the threatened BAP species are showing a fragile upturn in fortunes. Not so many years ago it was feared that the Large Garden Bumblebee B. ruderatus was heading for extinction in the UK. In recent years, however, the number of sightings has been on the increase. This maybe because more people with the skills to separate it from some very similar species are getting better at looking for it, but it may also be a real trend. In Essex it has been found feeding on Comfrey flowers in Cricket-bat Willow Salix alba var. caerulea plantations. This is neither an old nor species-rich habitat, but it provides the bee with what it needs: extensive areas of forage plants, exploiting Marsh woundwort Stachys palustris, Bindweeds Calystegia species and a few other plants that grow abundantly in the damp river valleys where the bat-willows are grown. The Brown-banded Carder Bee B. humilis and the Shrill Carder Bee B. sylvarum have both shown recent signs of range expansion up the Essex coastal from localised strongholds in the Thames estuary. B. humilis has been recorded fleetingly in Suffolk once more and hopefully can consolidate populations here. Hopefully, no more species will be lost to the county. B. bohemicus is seemingly rare and restricted to the Brecklands in the north-west, but it appears that this may have long been the case so its position might be regarded as stable. Its host, B. lucorum, is not scarce, so this is not a limiting factor for its survival. The Red-shanked Bumblebee B. ruderarius is living a precarious existence and appears to be one of the species most reliant on extensive, flower-rich grasslands in order to maintain stable populations. Its future lies in the hands of those managing the countryside at large. Some species are doubtless much more common than the preceding accounts suggest. Bombus jonellus needs careful examination to separate it from the very similar B. hortorum and must surely occur somewhere on the heaths of Breckland. B. ruderarius is likely to go un-noticed, dismissed as the much more common Red-tailed Bumblebee B. lapidarius. Several of the
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cuckoo bumblebees (B. vestalis, bohemicus and barbutellus) are very similarly marked and need microscopic examination to separate them, and may prove to be more common than we currently credit. For anyone wishing to venture into the world of entomology for the first time, I commend the genus as insects for people who “don’t do” insects. They are a small and manageable group, yet with complexities concerning accurate identification that require careful observation and, if needs be, some examination under the microscope. As indicated above, there is still much to be learnt about the distribution and abundance of these species in Suffolk, so there are rewards to be had in local discoveries and significant Vice County records. A number of available books are listed at the end of this paper to help the enquiring mind to take that first step to discovery. References Edwards, R. and Roy, H., eds. 2009. Provisional atlas of the aculeate Hymenoptera of Britain and Ireland. Part 7. Wallingford: Biological Records Centre. Edwards, R. and Telfer, M. G.., eds. 2002. Provisional atlas of the aculeate Hymenoptera of Britain and Ireland. Part 4. Huntingdon: Biological Records Centre. IBRA/ITE. 1980. Atlas of the Bumblebees of the British Isles. Institute of Terrestrial Ecology, Cambridge. Morley, C. 1899. The Hymenoptera of Suffolk. Part 1. Aculeata. James H. Keys, Plymouth. Morley, C. 1936. The Hymenoptera of Suffolk. Portio Secunda. Trans. Suffolk Nat. Soc. 3: 132–162. AIDS TO FURTHER STUDY Bumblebees (Naturalists’ Handbooks 6) Oliver E Prŷs-Jones and Sarah A Corbet. 2011. Published by Pelagic Publishing. This is a much welcome new edition of a long-standing “classic” dealing with bumblebee ecology, identification and conservation. Field Guide to the Bumblebees of Great Britain and Ireland Mike Edwards and Martin Jenner. 2009. Published by Ocelli A second edition of a very useful field guide to aid the identification of bumblebees, with brief notes on ecology and conservation. Bumblebees (New Naturalist series) Ted Benton, 2006. The magnum opus on bumblebees that one has come to expect from the New Naturalist series. Adrian Knowles Jessups Cottage London Road Capel St Mary Ipswich IP9 2JR
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G. Nobes Badenoch and Strathspey Conservation Group
Plate 5: Bombus hypnorum—the Tree Bumblebee (p. 26).
Plate 6: Bombus jonellus (p. 27 ).
G. Nobes G. Nobes
Plate 7: Bombus ruderatus male of the all black form (p. 32).
Plate 8: Bombus rupestris male, superficially similar to its host, the Red-tailed Bumblebee B. lapidarius (p. 33).
B. Jacobi Plate 9: The Shrill Carder Bee Bombus sylvarum; a BAP species currently absent from Suffolk, but there is a chance it may re-colonise (p. 36).