A. Dafni, P. Kevan, and B. Husband (eds.) Practical Pollination Biology. Enviroquest, Cambridge.

References 3 Klein, A. M., Vaissière, B. E., Cane, J., Steffan-Dewenter, I., Cunningham, S. A., Kremen, C. and Tscharntke, T. 2007 Importance of pollinators in changing landscapes for world crops. The Proceedings of the Royal Society of London, Series B. 274, 303-313. 2 A. Dafni, P. Kevan, and B. Husband (eds.) Practical Pollination Biology. Enviroquest, Cambridge. Results of wasp beer trapping 2007 in the UK and a comparison between open and wooded habitats Stuart P.M. Roberts 1 & Libor Dvorák 2 1) 1 Waterloo Road, Salisbury, Wiltshire, United Kingdom; e-mail: spmr@msn.com 2) Šumava NP and PLA Administration, Sušická 399, CZ-341 92 Kašperské Hory, Czech Republic; e-mail: libor.dvorak@npsumava.cz, lib.dvorak@seznam.cz Introduction The response of social wasps to different natural and chemical attractants has been part of a long term study in the USA (see LANDOLT et al. 2005 for review) and a comparable study in Europe (Dvorák & Landolt, 2006). A study on wasps in a variety of wooded ecosystems and their responses to landscape complexity at the UK and European scales has been published by Dvorák & Roberts (2007) and Dvorák (2007). Other recent work by Bacandritsos et al. (2006) has compared the relative effectiveness of three types of baited traps in Greece, and by Landolt et al. (2007) who published the results of wasp trapping with several chemical lures in Hungary. This current study brings together the results of the 2007 field experiment on the attractiveness of beer to different wasp species in open, non-wooded ecosystems in the United Kingdom, considers these findings in relation to a wider European survey conducted simultaneously. This work also assesses the responses of wasps to landscape complexity and seeks to make comparisons between the 2006 survey and that undertaken in 2007. Methodology A colourless and transparent Polyethylene bottle (1.5 or 2 litre capacity) was filled with 0.5 l of beer. The bottle was hung on a tree branch or fence post ca. 1.5 m above the ground; a free entrance for wasps was guaranteed. The bottle was placed in an area of open ground. The trap was installed ca. on 10 July (plus or minus several days) and recovered after 30 35 days. Localities under study Localities are written in order: locality number, county, locality, geographical coordinates and/or coordinates of the grid mapping, biotope specified as accurately as possible, altitude, date of installation and recovery, and recorder. Grid-referencing of sites in the Berkshire Downs and in the Chilterns has been kept at low resolution at the request of the landowners. Wasps were identified in each case by the recorder. UK 1 Wiltshire, Homington Road, SU13242776, open arable agricultural landscape, with harvested crop and wheat, 55 m a.s.l., 51.049 N, 1.8125 W, 11.vii.-12.viii.2007, S.P.M. Roberts UK 2 Wiltshire, Coombe Bissett Down, SU11072557, open, sheep grazed calcareous grassland, 110 m a.s.l., 51.0294 N, 1.8435 W, 11.vii.-12.viii.2007, S.P.M. Roberts 14 BWARS Newsletter, Spring 2008

UK 3 Wiltshire, Tottens Down Barn, SU11382422, open arable agricultural landscape, with fallow field and barley, 140 m a.s.l., 51.0172 N, 1.8391 W, 11.vii.-12.viii.2007, S.P.M. Roberts UK 4 Wiltshire, Odstock, SU14392642, cattle grazed grasslands; some re-seeded and some damp semi-natural with Juncus, 51.037 N, 1.7961 W, 50 m a.s.l., 11.vii.-12.viii.2007, S.P.M. Roberts UK 5 Wiltshire, Britford, SU16312842, ungrazed mowed tall grass meadow dominated by Holcus, 51.0549 N, 1.7687 W, 45 m a.s.l., 11.vii.-12.viii.2007, S.P.M. Roberts UK 6 Wiltshire, Salisbury, Waterloo Road, SU151295, suburban garden, with lawns, small shrubbery and flower beds, 50 m a.s.l., 51.06 N, 1.78W, 11.vii.-12.viii.2007, S.P.M. Roberts UK 7 - North Lincolnshire, Caistor, Caistor Moor, TA088012, fallow/unmanaged meadows, bordered by fragmented Hawthorn hedges (Crataegus monogyna), Grass species, plus: Nettle (Urtica dioca), Ragwort (Senecio jacobaea), Thistle (Cirsium sp.), 25 m a.s.l., 53.496259 N, 0.361376 W, 8.vii.-8.viii.2007, Alan Phillips UK 8 - North Lincolnshire, Grimsby, Irby Dales (1), TA193054, grass and scrub valley, occasionally grazed, grass species, plus: Nettle (Urtica dioca), Gorse (Ulex europaeus), Spear Thistle (Cirsium vulgare.), plus occasional Elder (Sambucus nigra), 35 m a.s.l., 53.531719 N, 0.201579 W, 9.vii.-9.viii.2007, Alan Phillips UK 9 - North Lincolnshire, Grimsby, Irby Dales (2), TA186050, previously felled woodland now replanted with Oak (Quercus robur) saplings (1.5m high), grass species, plus: Nettle (Urtica dioca), Dock (Rumex sp.), Thistle (Cirsium sp.), Bramble (Rubus fruticosus agg.), 45 m a.s.l., 53.528283 N, 0.212286 W, 9.vii.-9.viii.2007, Alan Phillips UK 10 - North Lincolnshire, Grimsby; Bradley, TA239049, edge of small, young, Cherry (Prunus) and Oak (Quercus robur) wood/copse (3m high), surrounded by arable land, grass species and Bramble (Rubus fruticosus agg.), 20 m a.s.l., 53.526163 N, 0.132416 W, 9.vii.-9.viii.2007, Alan Phillips UK11 Nottinghamshire, Clumber Country Park, South Lawns, SK627740, grassland/ parkland dotted with trees, periodically grazed by sheep, grass species plus areas of Bracken (Pteridium aquilinum), 45 m a.s.l., 53.259307 N, 1.061552 W, 11.vii.- 11.viii.2007, Alan Phillips UK 12 Hampshire, North Hayling, SU732034, garden bordering open grazing areas, 0 m a.s.l., 50.82 N, 0.96 E, 16.vii.-16.viii..2007, George R. Else UK 13 Berkshire, Lambourn, SU47, open arable agricultural landscape, with barley and wheat, 160 m a.s.l., 51.4 N, 1.4 W, 11.vii.-15.viii.2007, Simon Springate UK 14 Berkshire, Lambourn, SU37, open arable agricultural landscape, with harvested oil seed rape, 150 m a.s.l., 51.4 N, 1.4 W, 11.vii.-15.viii.2007, Simon Springate UK 15 Berkshire, Lambourn, SU37, open arable agricultural landscape, with wheat, 121 m a.s.l., 51.4 N, 1.4 W, 11.vii.-15.viii.2007, Simon Springate UK 16 Berkshire, Lambourn, SU47, open arable agricultural landscape, with wheat and some pasture, 111 m a.s.l., 51.4 N, 1.4 W, 11.vii.-15.viii.2007, Simon Springate UK 17 Berkshire, Lambourn, SU37, open arable agricultural landscape, with wheat and fallow field, 121 m a.s.l., 51.4 N, 1.4 W, 11.vii.-15.viii.2007, Simon Springate UK 18 Berkshire, Chilterns, SU68, open, horse grazed calcareous grassland, 145 m a.s.l., 51.5 N, 1.0 W, 13.vii.-17.viii.2007, Simon Springate UK 19 Berkshire, Chilterns, SU68, open arable agricultural landscape with calcareous seminatural grassland, 92 m a.s.l., 51.5 N, 1.1 W, 13.vii.-17.viii.2007, Simon Springate UK 20 Berkshire, Chilterns, SU68, open, cattle grazed agricultural landscape with nearby mixed plantation, 130 m a.s.l., 51.5 N, 1.1 W, 13.vii.-17.viii.2007, Simon Springate BWARS Newsletter, Spring 2008 15

UK 21 Berkshire, Chilterns, SU67, open, cattle grazed agricultural landscape, 43 m a.s.l., 51.5 N, 1.1 W, 13.vii.-17.viii.2007, Simon Springate UK 22 Berkshire, Chilterns, SU67, open reed bed, 48 m a.s.l., 51.4 N, 1.1 W, 13.vii.- 17.viii.2007, Simon Springate Results and discussion Across the 22 sites, a total of 1,002 specimens of 6 social wasp species were trapped (see Table 1). The commonest species were: Common wasp (Vespula vulgaris), German Wasp (Vespula germanica), and Median Wasp (Dolichovespula media). Only V. vulgaris was found in all traps. The Hornet (Vespa crabro), normally associated with wooded biomes, was represented in eight sites and formed 8% of the total catch. The species assemblage is completed with Red Wasp (Vespula rufa) and Tree Wasp (Dolichovespula sylvestris), both species being rarely attracted to sweet baits. All data are summarised in Table 1. The numbers of individuals at each locality varied between 5 and 154, with the mean at 45.5 Similarly large numbers were recorded in only a few other European countries as part of the wider survey. Individual traps were sometimes richer, (with up to 228 specimens) but only Austria and France had such a high mean number as the UK. The largest individual number of specimens code loc. Vcra Vger Vvul Vruf Dmed Dsyl sum UK1 7 19 1 27 UK2 37 34 1 11 83 UK3 3 5 8 UK4 9 14 23 UK5 2 1 4 7 UK6 4 12 34 50 UK7 46 103 1 4 154 UK8 5 37 8 50 UK9 3 72 1 16 92 UK10 5 2 1 8 UK11 48 8 2 58 UK12 3 5 3 12 1 24 UK13 2 15 38 6 61 UK14 12 112 4 128 UK15 2 18 20 UK16 4 5 17 26 UK17 18 6 24 UK18 11 21 21 1 54 UK19 5 5 UK20 10 17 19 46 UK21 7 19 5 31 UK22 2 3 15 3 23 sum 84 190 590 5 132 1 1002 Table 1. The wasp numbers at each locality. Explanations: Vcra Vespa crabro, Vger Vespula germanica, Vvul V. vulgaris, Vruf Vespula rufa, Dmed Dolichovespula media, Dsyl Dolichovespula sylvestris. 16 BWARS Newsletter, Spring 2008

came from the Czech Republic, Austria and Slovakia, where the assemblages showed proportionally less V. vulgaris compared to the other species than was recorded in the UK. The situation in Central Europe differs also in the absolute numbers (38%) of V. crabro. This can be explained by the species biotope preference: V. crabro does not occupy inner parts of forests, but mainly forest and woodland margins and parklands and it can hunt in open landscape very well. The other common (and in the UK, spreading) species, D. saxonica, is attracted only very occasionally to sweet baits. This species was not trapped at all during the 2007 survey at 141 European sites. The most interesting wasp species trapped with beer in open ecosystems across the continent were Dolichovespula omissa and Ancistrocerus trifasciatus (neither appearing in the UK traps). The impact of simple 1, and complex 2 landscape structures was studied across all localities. Localities 1-3, 6-9 and 11-17 lie within a simple landscape and localities 4, 5, 10 and 18-22 within a diverse landscape. Fig. 1 shows that the most obvious differences lie with the responses of Vespula vulgaris and Vespula germanica. V. vulgaris has 13% greater abundance in sites in simple landscapes, whereas V. germanica has 8% greater abundance in the more complex landscape matrix. Vespa crabro, a species predominantly associated with woodlands, is present in smaller numbers overall, but is more prevalent in complex landscapes which will contain wooded areas. Dolichovespula media, which is able to exploit a wider range of potential nest sites than V. crabro, shows no significant preferences for particular landscape structure. When comparisons are drawn between the various woodland habitats surveyed in 2006 (Dvorák & Roberts, 2007) with the open habitats studied in 2007 a number of significant differences become apparent (Fig. 2). Vespa crabro accounts for 42% of all trapped wasps in woodland sites, and although still present, it is far less plentiful in open habitats and forms only 8% of the total number of wasps trapped. Vespula vulgaris is also a plentiful insect in woodlands (38%), but it is even more significant in open habitats (59%). V. germanica is generally a sylviphobic species (Niedl & Deneš, 1969; Dvorák, 2007; Dvorák & Roberts, 2007) with low numbers being found (2%) but in open habitats it accounts for 19 % of the wasps trapped. Dolichovespula media shows no clear preference for either habitat, with similar numbers of wasps being caught in the two years of the extended study. It is probable that the ability of this species to utilise a variety of trees, shrubs and man made structures, rather than tree cavities, as possible nest sites ensures that it can exploit a wide variety of wooded and open habitats. It is also possible that the comparable numbers in both woodland and open areas reflect the fact that D. media is relatively recent colonist and a species that is expanding its range in the UK. Conclusions 1. Beer is very attractive for several wasp species occurring in open and arable ecosystems. 2. Vespula vulgaris is the dominant wasp species in open habitats. 3. The numbers of Vespula vulgaris were higher at sites in simple landscapes. 4. Vespa crabro, Vespula vulgaris, Vespula germanica and Dolichovespula media are the only wasp species which can be regularly trapped with beer in both open and woodland ecosystems. 5. Vespa crabro, a species typical of more wooded biotopes, will forage widely into open habitats. 6. Vespula germanica is a sylviphobic species, but is a significant part of the open habitat wasp fauna. 1 Simple landscapes are dominated by a single land use type. In these study sites these are agricultural or other anthropogenic habitats with very little natural or semi-natural vegetation. 2 Diverse landscapes have a mosaic of semi-natural, agricultural and anthropogenic habitats. BWARS Newsletter, Spring 2008 17

Open Habitats 70 60 percentage 50 40 30 20 Complex Simple 10 0 Vcra Vger Vvul Vruf Dmed Dsyl Dsax Species Fig. 1. The percentage representation of wasp species at sites in complex (197 ex.) and simple (778 ex.) landscapes. Explanations: Vcra Vespa crabro, Vger Vespula germanica, Vvul V. vulgaris, Vruf Vespula rufa, Dmed Dolichovespula media, Dsyl Dolichovespula sylvestris, Dsax Dolichovespula saxonica. 70 Woodland v. Open habitats percentage 60 50 40 30 20 10 Woodland Open 0 Vcra Vger Vvul Vruf Dmed Dsyl Dsax Species Fig. 2. The percentage representation of wasp species at woodland (1,127 ex.) and open (1,002 ex.) sites. Explanations: Vcra Vespa crabro, Vger Vespula germanica, Vvul V. vulgaris, Vruf Vespula rufa, Dmed Dolichovespula media, Dsyl Dolichovespula sylvestris, Dsax Dolichovespula saxonica. 18 BWARS Newsletter, Spring 2008

Acknowledgements The authors wish to thank all the people who participated at this project for their enthusiasm, for running the traps and identifying the wasps. Special thanks are due to Simon Springate (University of Reading) who managed all the wasp trapping in the Chilterns and Berkshire Downs as part of the ALARM Field Site Network throughout the summer of 2007. Simon was funded by the EU FP6 project ALARM (EU Framework 6 Integrated Project GOCE-CT-2003-506675.) www.alarmproject.ufz.de. We are also grateful to Nico Vereecken for commenting on the manuscript. References Bacandritsos N., Papanastasiou I., Saitanis C. & Roinioti E., 2006: Three non-toxic insect traps useful in trapping wasp enemies of honey bees. Bulletin of Insectology 59 (2): 135-145. Dvorák L. 2007 Social wasps (Hymenoptera: Vespidae) trapped with beer in European forest ecosystems. Acta Musei Moraviae, Scientiae biologicae (Brno) 92: 181-204 Dvorák L. & Landolt P.J., 2006: Social wasps trapped in the Czech Republic with syrup and fermented fruit and comparison with similar studies (Hymenoptera Vespidae). Bulletin of Insectology 59 (2): 115-120. Dvorák L. & Roberts S.P.M., 2007: Results of Wasp beer trapping 2006 in the UK. BWARS Newsletter, Spring 2007 Landolt P.J., Pantoja A., & Green D., 2005: Yellowjacket wasps (Hymenoptera: Vespidae) trapped in Alaska with Heptyl Butyrate, Acetic Acid and Isobutanol. Journal of Entomological Society of British Columbia 102: 35-42. Landolt P.J., Tóth M. & Jósvai J., 2007: First European report of social wasps trapped in response to acetic acid, isobutanol, 2-methyl-2-propanol and heptyl butyrate in tests conducted in Hungary. Bulletin of Insectology 60 (1): 7-11. Niedl, J., & Deneš. K., 1969: Výsledky dosavadního prùzkumu rozšírení vos na Treboòsku (Bisherige Forschungsergebnisse der Verbreitung von Vespoidea in Gebiet von Treboò in Südböhmen). Sborník Jihoèeského muzea v Èeských Budìjovicích, Prírodní vìdy 9: 15-33. Erratum to the Autumn 2007 BWARS Newsletter On page 11, 2 nd paragraph should be a plentiful supply of food decreased the length. What, Where, When? What is a record? Points to consider Mike Edwards Lea-side, Carron Lane, MIDHURST, West Sussex GU29 9LB This piece was initially meant as an apology to all who wondered why the bee shown on the pile of dead stems on the rear inside cover of the last Newsletter was not the solitary bee Osmia bicolor - which of course is what it was, not a bumblebee at all! My mistake highlights the need to be careful when giving pronouncements - and the need to look at the circumstantial evidence as well as the object. If I had spent a little more time looking at the relative size of the leaf and the bee, instead of concentrating on the bee alone, I would have recognised that the suggestion of it BWARS Newsletter, Spring 2008 19