Dry grassland within the urban matrix acts as favourable habitat for different pollinators including endangered species [original]

ORIGINAL ARTICLE

Dry grassland within the urban matrix acts as favourable

habitat for different pollinators including endangered species

Anita Judit Grossmann

1,2

| Johann Herrmann

1,2

| Sascha Buchholz

2,3

Anika Kristin Gathof

1,2

Department of Ecology, TU Berlin, Berlin,

Germany

Berlin-Brandenburg Institute of Advanced

Biodiversity Research (BBIB), Berlin, Germany

Institute of Landscape Ecology, University of

Münster, Münster, Germany

Correspondence

Anika Kristin Gathof, Department of Ecology,

TU Berlin, 12165 Berlin, Germany.

Email: [email protected]

Funding information

German Federal Ministry of Education and

Research, Grant/Award Number: 01LC1501

Editor: Laurence Packer and Associate Editor:

Sandra Rehan

Abstract

1. This study highlights the potential of urban dry grasslands for diverse pollinator

communities of wild bees and hoverflies, including rare and endangered species.

2. By using pan trap sampling on 49 study sites distributed across the urban environ-

ment, responses of wild bee and hoverfly communities to urban features at two

spatial scales (urban matrix and local habitat) were examined.

3. A total of 1246 hoverfly individuals (Syrphidae) from 31 species and 1463 bee indi-

viduals (Apoidea) from 107 species were collected. Our analysis showed that hover-

flies are impacted by urban matrix features and local floral resources, whereas wild

bees only respond to patch size at the local habitat scale and endangered wild bee

species additionally to non-native pollinator-friendly plants.

4. Given the different responses of wild bees and hoverflies to the urban environment,

we recommend multi-taxon approaches for urban conservation practice. Urban dry

grasslands and the diversity of pollinator-friendly plants, including non-native spe-

cies, should be conserved and promoted to support urban pollinator diversity.

KEYWORDS

dry grassland, hoverflies, multi-taxon approach, pollinator diversity, urban spatial scales, wild bees

INTRODUCTION

Previous studies on urban biodiversity have contributed to an increas-

ing awareness of the biological value and ecological importance of cit-

ies as habitats for flora and fauna, including pollinating insects

(Ayers & Rehan, 2021; Baldock et al., 2019; Theodorou et al., 2020).

Even though expanding urbanisation processes are fuelling species

extinction worldwide through habitat destruction and fragmentation

(Spotswood et al., 2021), cities can demonstrably provide a refuge,

also for rare and endangered pollinators (Buchholz et al., 2020; Hall

et al., 2017). The heterogeneous urban matrix with green spaces such

as parks, gardens, roadside greenery and remnants of native habitats

promotes the occurrence of different species by providing niches and

a diversity of resources (Ayers & Rehan, 2021; Baldock et al., 2019;

Twerd & Banaszak-Cibicka, 2019) with a generally lower use of pesti-

cides (Daniels et al., 2020). Nevertheless, the results of previous stud-

ies demonstrate that cities are complex ecosystems with both positive

and negative impacts on urban pollinators, with no universal

responses (Wenzel et al., 2020; Zaninotto et al., 2020). Pollinating

insect groups can respond in different ways to urbanisation effects

(Theodorou et al., 2020) and various urban ecosystems can elicit dif-

fering responses in species communities owing to different site-

specific management methods and the accessibility of resources

(Ayers & Rehan, 2021; Dylewski et al., 2019).

Received: 9 May 2022 Accepted: 19 September 2022

DOI: 10.1111/icad.12607

This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium,

provided the original work is properly cited.

Insect Conserv Divers. 2023;16:97–109. wileyonlinelibrary.com/journal/icad 97

As an important component of urban green infrastructure, dry

grasslands are globally spread and distributed across the urban matrix

exposed to different intensities of urbanisation and anthropogenic

recreational activities (von der Lippe et al., 2020). Urban dry grass-

lands can create suitable habitats for diverse communities (Albrecht &

Haider, 2013; Möller et al., 2019; Venn et al., 2013) but have hardly

been studied in context of urban pollinators (but see Kadlec et al.,

2008 for butterflies). Some urban studies have generally examined

grasslands (Buchholz et al., 2020; Zaninotto et al., 2020), wastelands

(Turo & Gardiner, 2021; Twerd & Banaszak-Cibicka, 2019) or com-

pared grassland sites with other habitats (Dylewski et al., 2019;

Threlfall et al., 2015), while most urban studies dealt with allotments/

community gardens (Baldock et al., 2019; Lanner et al., 2020;

Makinson et al., 2017), urban public gardens/parks (Banaszak-

Cibicka & _

Zmihorski, 2012; Geslin et al., 2016) and cemeteries/

churchyards (Bates et al., 2011; Normandin et al., 2017).

In cities, dry grassland habitats have often been created through

human intervention by the closure of transport and industrial areas, tem-

porary construction measures or military use (Langner & Endlicher, 2007;

Sukopp & Wittig, 1998). Fallow sites temporarily fall out of use, allowing

a diverse community of species to emerge devoid of the use of any pes-

ticides. Without human intervention, spontaneous vegetation can

develop dynamically on site, often with a high proportion of non-native

plant species (Godefroid & Koedam, 2007;Turo&Gardiner,2021)and

pollen- and nectar-rich wild flowering plants, as well as a high proportion

of absorbent plant material and open soil patches (Hunter, 2014). An

interplay of disturbances, succession processes, uncontrolled environ-

mental conditions and the past land use often leads to high variability, a

great diversity of plants and good habitat potential for pollinating insects

(Turo & Gardiner, 2021; Twerd & Banaszak-Cibicka, 2019). In general,

urban dry grasslands act as important secondary habitats and can be con-

sidered true biodiversity hotspots (Albrecht & Haider, 2013;Melliger&

Rusterholz, 2017).

Despite their importance for nature conservation (Vrahnakis

et al., 2013), dry grassland sites are becoming increasingly rare in the

landscape due to intensification of management and abandonment

resulting in a lack of habitat dynamics (Hemeier, 2005). In urban envi-

ronments, heavy building pressure, rapid expansion of traffic infra-

structure and differing aesthetic perceptions of green spaces lead to a

decline of these biotopes (Hunter, 2014). In addition, if urban dry

grassland is left fallow for too long, growth of woody vegetation dis-

places herbaceous flowering plants and increasingly changes the habi-

tat potential, especially for pollinators (Saure, 2005). The grassland

biotope, can provide suitable habitat conditions for diverse pollinators

due to plant diversity and resource availability throughout the year as

well as from patchy vegetation structure (Albrecht & Haider, 2013)

and a high proportion of deadwood. Open sandy soils provide impor-

tant nesting structures for ground-nesting species and the opportu-

nity to form puddles, which is especially important for the larval

development of many hoverfly species (Speight et al., 2013)—

structures that hardly exist anymore in cities.

To examine the potential of dry grassland as a habitat for pollinators

within an urban context, we use a multi-taxon approach namely wild

bees and hoverflies, both very important pollinators from an ecological

and economic perspective (Doyle et al., 2020; Theodorou et al., 2020).

Selected pollinator groups also differ in their ecological requirements as

well as in their life history traits, which allows us to illustrate broader,

multi-layered and taxon-specific effects of urbanisation parameters.

Hoverflies have diverse requirements for larval habitat, while bees often

need species-specific nesting conditions and materials and they show

specialisation in their pollen-collecting behaviour (oligolecty).

We aim to identify how pollinator species respond to urban land-

scape matrix using impervious surface and a newly developed connec-

tivity measure that incorporates the three-dimensional urban

environment as predictors. Further, we test the effects of local site

parameters (patch size, cover of pollinator-friendly plants, cover of

non-native pollinator-friendly plants). Finally, we want to find out

whether rare and endangered species react differently to urban land-

scape matrix and local site predictors.

Based on current studies, we expect a negative impact of

urbanisation on hoverfly diversity (Baldock et al., 2015;Persson

et al., 2020) and none on wild bees even though some studies have

found positive or negative impacts (Wenzel et al., 2020). Previous

studies have examined isolation and found negative influences on

pollinator diversity (Buchholz et al., 2020). Therefore, connectivity

is expected to have a positive impact on both hoverfly and bee

diversity as it can link habitats, allowing a larger area to be used as

habitat. Further, we expect positive effects of pollinator-friendly

vegetation variables since local vegetation is known to be an impor-

tant driver to enhance pollinator diversity in cities (Banaszak-

Cibicka et al., 2016; Dylewski et al., 2019; Wastian et al., 2016), as

well as patch size (Buchholz et al., 2020; Jauker et al., 2013). Due

to the fact that non-native plant species are widespread in urban

environments (Threlfall et al., 2015), we expect a positive influence

on pollinator diversity (Buchholz & Kowarik, 2019;Wilson&

Jamieson, 2019). Staab et al. (2020) demonstrated that non-native

plants could increase food resources for urban pollinators, espe-

cially when native species have already declined. As rare and

endangered species often have specialisations and are more

strongly bound to their habitat (Bogusch et al., 2020), we expect

themtoshowamorenegativeresponsetourbanisation,whilethey

benefit from local vegetation, patch size and connectivity to a

greater extent.

Based on this, we derive following hypotheses:

i. Hoverfly diversity is negatively affected by urbanisation while

wild bee diversity is unaffected, and both pollinator groups are

positively impacted by 3D connectivity at the urban matrix scale.

Because of their different ecologies, hoverfly and wild bee diver-

sity respond in different intensities to both variables.

ii. Patch size and pollinator-friendly vegetation variables at the local

habitat scale have a positive effect on hoverfly and wild bee

diversity. The origin of plants has a positive influence on pollina-

tor diversity.

iii. Local habitat variables (patch size and vegetation) boost endan-

gered pollinator species, whereas urbanisation has a negative

effect.

98 GROSSMANN ET AL.

MATERIAL AND METHODS

Study system and area

The study was conducted in Berlin, the capital of Germany, which

covers 891.1 km

and is home to approximately 3.6 million people.

For our study system, we used a novel research platform, the CitySca-

peLab Berlin, which uses urban grassland as model ecosystem (von

der Lippe et al., 2020) and allowed us to study urbanisation effects on

biodiversity patterns of pollinators. Urban grassland is an essential ele-

ment of green spaces within cities worldwide and harbours a wide

range of plants and animals (von der Lippe et al., 2020). Regarding pol-

linators, it provides foraging resources for hoverflies and serves as

important habitat for wild bees (Dylewski et al., 2019; Hall

et al., 2017). For our study design, we selected 49 urban grasslands

distributed across the city, 44 located in and 5 outside of Berlin. Each

study site consisted of a dry grassland patch that encompasses one

randomly located plot with a standardised size (4 4 m) for sampling

environmental variables (vegetation variables and temperature) and

pollinators (von der Lippe et al., 2020).

Pollinator sampling

Pollinator sampling took place during summer 2017 using pan traps

across three sampling rounds approximately 6 weeks apart (29 May to

02 June, 03–07 July, 04–08 Sep). Pan trapping represents a common

passive method for catching pollinators based on visual attraction

(Dafni et al., 2005; Kearns & Inouye, 1993), which has been applied in

other studies that focused on both wild bees and hoverflies (Bates

et al., 2011; Persson et al., 2020).

Although pan trap sampling can bias the collection towards, for

example, small-bodied bees or specific genera (Cane et al., 2000;

Portman et al., 2020), we selected this method because it allowed us

to simultaneously sample all 49 sites with the same sampling effort;

reduce collector bias and temporal bias; and obtain a standard esti-

mate of pollinator species richness and abundance co-occurring within

a site (Devigne & De Biseau, 2014; Westphal et al., 2008). Further-

more, we assume that—if at all—any systematic bias in the composi-

tion of bees and hoverflies collected by pan traps would be consistent

across all of our study sites. After colouring the plastic bowls (radius:

7.25 cm, depth: 5 cm) by spraying them yellow, blue and white with

Sparver Leuchtfarbe (Spray-Colour GmbH, Merzenich, Germany), we

placed a triplet of pan traps on the study sites. We used three differ-

ent colours to increase the catching performance and attract more

pollinator species (Vrdoljak & Samways, 2012). The plastic bowls were

pinned on the top of wooden sticks at the height of the surrounding

vegetation (approximately 30 cm above the ground) and filled with

approximately 300 ml of 4% formaldehyde solution and a drop of

detergent to break the surface tension. When selecting sampling ses-

sions, good weather conditions for pollinator activity were taken into

account (minimum of 15C, low wind, no rain, and dry vegetation). All

caught pollinators were transferred to vials with ethanol and labelled

with the site information, date and collector name. Subsequently, all

collected pollinators were pre-sorted to filter out bycatch and only

the bees and hoverflies were dried, pinned and identified to their low-

est possible taxonomic level using taxonomic identification keys for

bees (Amiet, 1996; Amiet et al., 1999,2001,2004,2007,2010;

Gokcezade et al., 2010) by A. J. Grossmann and A. K. Gathof and for

hoverflies (Bartsch et al., 2009a,2009b) by J. Herrmann. Since we

focused exclusively on wild pollinators in this study, we excluded the

510 caught specimens of Apis mellifera (the honeybee) from the data

set, given that their abundance follows other seasonal patterns than

those of wild bees (Tommasi et al., 2004). Taxonomy of wild bees fol-

lowed the nomenclature of Scheuchel and Willner (2016) and taxon-

omy of hoverflies followed the nomenclature of Speight et al. (2013).

Before specimen vouchering and inclusion into the collection of the

TU Berlin (Department of Ecology, Ecosystem Science, Rothenburgstr,

Berlin), all catches were finally verified by the external wild bee expert

Dr. Christoph Saure, Büro für tierökologische Studien, Berlin.

Environmental variables

We determined, at two spatial scales, the five environmental variables

(1) urbanisation, (2) 3D connectivity, (3) patch size, (4) cover of

pollinator-friendly plants, and (5) cover of pollinator-friendly non-

native plants to describe the environment of 49 study sites obtained

as part of CityScapeLab Berlin (von der Lippe et al., 2020). The vari-

ables (1) and (3) were directly adopted from the dataset, whereas (2),

(4) and (5) were modified for this study.

At the urban matrix scale, we referred to the variables (1) urbani-

sation and (2) 3D connectivity (von der Lippe et al., 2020). Both vari-

ables have been identified as important predictors for wild bee

community composition within cities in previous studies (Geslin

et al., 2016; Martins et al., 2017), although for connectivity, only two

dimensions have been considered so far. For (1) we relied on a fre-

quently used urbanisation measure and used the proportion of imper-

vious surface (Choate et al., 2018; Fortel et al., 2014; Geslin

et al., 2016) within a 500 m buffer around the plot (SenUDH, 2011).

The buffer radius of 500 m was defined as this distance reflects the

radius of action of most wild bees (Zurbuchen et al., 2010). Although

hoverflies can be more mobile (Doyle et al., 2020; Lysenkov, 2009),

they are also sufficiently considered in this buffer radius. As pollina-

tors are mobile and use airspace in particular, our (2) 3D connectivity

variable is based on the Hanski’s habitat connectivity index

(Hanski, 1994,1999) and combines distances to other dry grasslands

(SenUDH, 2014a) with area sizes and building heights to provide a 3D

connectivity. The factor weighting the distance that originally

describes the dispersal capacity of species was modified to take into

account the 3D urban landscape context. To do so, the building

heights (SenUDH, 2014b) were summed up in corridors of 25 m

radius around the connecting lines between patches. The distance

thus increases with more and higher buildings in between patches

(resulting in less connectivity). All spatial analyses were made in QGIS

Version 2.18.11 (QGIS Development Team, 2016) using the tools

URBAN DRY GRASSLANDS AS HABITATS FOR POLLINATORS 99

Edge distance vector of the Conefor Inputs plugin (Saura &

Torné, 2009) and Zonal statistics. At the local habitat scale, we used

the variables (3) patch size, (4) cover of pollinator-friendly plants and

(5) cover of pollinator-friendly non-native plants to characterise the

local habitat features of each study site. Cover of pollinator-friendly

plants was recorded within each plot (4 4 m) as a measure of local

resource availability using the Braun-Blanquet approach (van der

Maarel & Franklin, 2012). In addition, we considered the cover of

pollinator-friendly non-native plants in particular, as previous studies

have demonstrated that non-native plants possibly cause novel eco-

system interactions (Davis et al., 2018; Schirmel et al., 2016;

Schweiger et al., 2010). For this variable, the coverage of all

pollinator-friendly non-native plants was summed up.

Data preparation and statistical analysis

In our final data set, each sample unit included the pooled data from all

three pan traps per study site and all sampling rounds. To describe the

alpha diversity, we determined the (a) abundance, (b) species richness,

and the (e) number of endangered species for each study site separately

for wild bees and hoverflies. To assess the (d) abundance and (e) number

of endangered species, we referred to the Red List by Saure (2005)for

bees and the Red List by Saure (2018) for hoverflies. All species falling

under categories 1, 2, 3, V and G as well as new found species for Berlin

were considered as endangered species. Because of only four captured

hoverfly individuals that could be assigned to these categories, we did

not conduct further analysis on endangered hoverflies (iii). Effects of the

environmental variables (1) urbanisation, (2) 3D-connectivity, (3) patch

size, (4) cover of pollinator-friendly plants, (5) cover of pollinator-friendly

non-native plants on (a) abundance, (b) species richness, (c) Shannon

diversity, (d) abundance of endangered species and the (e) number of

endangered species were tested using multivariate generalised linear

models (GLMs). Predictors were tested for intercorrelation beforehand

and only uncorrelated predictors were included in the models. Quasipois-

son models were used for count data ([a] abundance, [b] species richness,

[d] abundance of endangered species and the [e] number of endangered

species) due to overdispersion. Gaussian model was applied for the

meansofanalysisofdeviance.Asagoodness-of-fit measure, pseudo R

based on null and residual deviance was calculated (Zuur et al., 2009).

RESULTS

We collected a total of 1246 hoverfly individuals (Syrphidae) from

31 species (Table 1) and 1463 bee individuals (Apoidea) from 107 spe-

cies (Table 2) distributed across the urban matrix (Figure 1). Helophilus

trivittatus (610 individuals), Helophilus pendulus (245) Eristalis arbus-

torum (192), and Episyrphus balteatus (62) were the most abundant

hoverfly species. We found two Red-Listed (Berlin) hoverfly species

(Saure, 2018)inChrysotoxum verralli (4) and Sericomyia silentis (1). The

most abundant wild bee species were Lasioglossum morio (139), Lasio-

glossum calceatum (95), Bombus terrestris (67) and Lasioglossum laticeps

(51). Among wild bees, we identified 27 Red-Listed (Berlin) species

(Saure, 2005), which represented 25% of all collected wild bee species

with Anthidium punctatum,Halictus submediterraneus,Osmia bicolor

and Tetraloniella dentata considered particularly threatened with

extinction. In addition, we could record a new finding for the study

region Berlin with Lasioglossum fulvicorne. While the Red List (endan-

gered species) species of wild bees could be detected in the whole

urban matrix area, we could find the hoverfly Red List species only at

four sites concentrated at the eastern outskirts (Figure 1).

The GLM results showed several significant relationships

between environmental variables and biodiversity of hoverflies

(Figure 2) and wild bees (Figure 3). Hoverfly species richness

TABLE 1 List of captured hoverfly species and the number of

respective specimens

Hoverfly species Captured specimens

Cheilosia vernalis (FALLÉN, 1817) 1

Chrysotoxum bicinctum (LINNAEUS, 1758) 1

Chrysotoxum festivum (LINNAEUS, 1758) 3

Chrysotoxum verralli (COLLIN, 1940) 4

Dasysyrphus albostriatus (FALLÉN, 1817) 4

Didea intermedia (LOEW, 1854) 1

Episyrphus balteatus (DEGEER, 1776) 62

Eristalinus sepulchralis (LINNAEUS, 1758) 5

Eristalis abusiva (COLLIN, 1931) 1

Eristalis arbustorum (LINNAEUS, 1758) 192

Eristalis intricaria (LINNAEUS, 1758) 1

Eristalis nemorum (LINNAEUS, 1758)1

Eristalis similis (FALLÉN, 1817) 7

Eristalis tenax (LINNAEUS, 1758) 5

Ferdinandea cuprea (SCOPOLI, 1763) 1

Helophilus pendulus (LINNAEUS,1758) 245

Helophilus trivittatus (FABRICIUS, 1805) 610

Melanostoma mellinum (LINNAEUS, 1758) 25

Melanostoma scalare (FABRICIUS, 1794) 1

Merodon equestris (FABRICIUS, 1794) 13

Myathropa florea (LINNAEUS, 1758) 27

Pipiza festiva (MEIGEN, 1822) 1

Scaeva selenitica (MEIGEN, 1822) 3

Sericomyia silentis (HARRIS, 1776) 1

Sphaerophoria batava (GOELDLIN, 1974) 2

Sphaerophoria scripta (LINNAEUS, 1758) 19

Syritta pipiens (LINNAEUS, 1758)1

Syrphus ribesii (LINNAEUS, 1758) 2

Syrphus vitripennis (MEIGEN, 1822) 2

Volucella inanis (LINNAEUS, 1758) 1

Xylota segnis (LINNAEUS, 1758) 4

100 GROSSMANN ET AL.

TABLE 2 List of captured wild bee species and the number of

respective specimens

Bee species Captured specimens

Andrena alfkenella (PERKINS, 1914) 1

Andrena argentata (SMITH, 1844) 19

Andrena barbilabris (KIRBY, 1802) 2

Andrena bimaculata (KIRBY, 1802) 1

Andrena cineraria (LINNAEUS, 1758) 1

Andrena denticulata (KIRBY, 1802) 1

Andrena dorsata (KIRBY, 1802) 11

Andrena flavipes (PANZER, 1798) 44

Andrena haemorrhoa (FABRICIUS, 1781) 2

Andrena helvola (LINNAEUS, 1758) 1

Andrena nigroaenea (KIRBY, 1802) 8

Adrena nigrospina (THOMSON, 1872) 4

Andrena nitida (MÜLLER, 1776) 14

Andrena semilaevis (PÉREZ, 1903) 1

Andrena subopaca (NYLANDER, 1848) 13

Andrena tibialis (KIRBY, 1802) 1

Anthidium punctatum (LATREILLE, 1809) 1

Anthophora furcata (PANZER, 1798) 2

Apis mellifera (LINNAEUS, 1758) 510

Bombus bohemicus (SEIDL, 1837) 3

Bombus hortorum (LINNAEUS, 1761) 2

Bombus hypnorum (LINNAEUS, 1758) 5

Bombus lapidarius (LINNAEUS, 1758) 15

Bombus lucorum (LINNAEUS, 1761) 3

Bombus pascuorum (SCOPOLI, 1763) 23

Bombus pratorum (LINNAEUS, 1761) 9

Bombus ruderarius (MÜLLER, 1776) 1

Bombus rupestris (FABRICIUS, 1793) 26

Bombus soroeensis (FABRICIUS, 1776) 2

Bombus sylvarum (LINNAEUS, 1761) 1

Bombus sylvestris (LEPELETIER, 1832) 3

Bombus terrestris (LINNAEUS, 1758) 67

Bombus vestalis (GEOFFROY, 1785) 6

Chelostoma rapunculi (LEPELETIER, 1841) 1

Coelioxys conica (LINNAEUS, 1758) 2

Dasypoda hirtipes (FABRICIUS, 1793) 21

Halictus confusus (SMITH, 1853) 3

Halictus rubicundus (CHRIST, 1791) 11

Halictus sexcinctus (FABRICIUS, 1775) 6

Halictus subauratus (ROSSI, 1792) 5

Halictus submediterraneus (PAULY, 2015) 2

Halictus tumulorum (LINNAUES, 1758) 17

Heriades crenulatus NYLANDER, 1856 3

Heriades truncorum (LINNAEUS, 1758) 3

Hoplitis adunca (PANZER, 1798) 6

(Continues)

TABLE 2 (Continued)

Bee species Captured specimens

Hoplitis anthocopoides (SCHENCK, 1853) 1

Hoplitis leucomelana (KIRBY, 1802) 2

Hylaeus angustatus (SCHENCK, 1861) 1

Hylaeus brevicornis (NYLANDER, 1852) 1

Hylaeus communis (NYLANDER, 1852) 46

Hylaeus confusus (NYLANDER, 1852) 3

Hylaeus dilatatus (KIRBY, 1802) 3

Hylaeus gredleri (FÖRSTER, 1871) 8

Hylaeus hyalinatus (SMITH, 1842) 20

Hylaeus punctatus (BRULLÉ, 1832) 1

Hylaeus signatus (PANZER, 1798) 1

Hylaeus sinuatus (SCHENCK, 1853) 1

Lasioglossum aeratum (KIRBY, 1802) 6

Lasioglossum albipes (FABRICIUS, 1781) 1

Lasioglossum brevicorne (SCHENCK, 1853) 1

Lasioglossum calceatum (SCOPOLI, 1763) 95

Lasioglossum fulvicorne (KIRBY, 1802) 1

Lasioglossum laticeps (SCHENCK, 1869) 51

Lasioglossum leucopus (KIRBY, 1802) 1

Lasioglossum leucozonium (SCHRANK, 1781) 18

Lasioglossum lucidulum (SCHENCK, 1861) 25

Lasioglossum monstrificum (MORAWITZ, 1891) 7

Lasioglossum morio (FABRICIUS, 1793) 139

Lasioglossum pauxillum (SCHENCK, 1853) 19

Lasioglossum quadrinotatum (KIRBY, 1802) 2

Lasioglossum setulosum (STRAND, 1909) 2

Lasioglossum sexnotatum (KIRBY, 1802) 1

Lasioglossum sexstrigatum (SCHENCK, 1869) 30

Lasioglossum villosulum (KIRBY, 1802) 2

Macropis europaea WARNCKE, 1973 1

Megachile circumcincta (KIRBY, 1802)6

Megachile ligniseca (KIRBY, 1802) 7

Megachile maritima (KIRBY, 1802) 1

Megachile rotundata (FABRICIUS, 1787) 2

Megachile versicolor (SMITH, 1844) 2

Megachile willughbiella (KIRBY, 1802) 1

Melecta albifrons (FORSTER, 1771) 2

Melitta leporina (PANZER, 1799) 1

Nomada alboguttata (HERRICH-SCHÄFFER, 1839) 1

Nomada flavoguttata (KIRBY, 1802) 1

Nomada flavopicta (KIRBY, 1802) 1

Nomada lathburiana (KIRBY, 1802) 1

Nomada moeschleri (ALFKEN, 1913) 4

Nomada panzeri (LEPELETIER, 1841) 3

Nomada ruficornis (LINNAEUS, 1758) 3

Osmia bicolor (SCHRANK, 1781) 1

(Continues)

URBAN DRY GRASSLANDS AS HABITATS FOR POLLINATORS 101

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