Introduced honeybees (Apis mellifera) in orchid pollination: surrogate pollinators or pollen wasters?

doi:10.21203/rs.3.rs-3145216/v1

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Introduced honeybees (Apis mellifera) in orchid pollination: surrogate pollinators or pollen wasters?

https://doi.org/10.21203/rs.3.rs-3145216/v1

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Biological invasion is one of the leading threats to global biodiversity. Invasive species can change the structure and dynamics of landscapes, communities, and ecosystems, and even alter mutualistic relationships across species such as pollination. Orchids are one of the most threatened plant families globally and known to have established specialised pollination mechanism to reproduce, yet the impact of invasive bees on orchid reproduction has not been comprehensively assessed. We conduct a literature survey to document global patterns of the impact of invasive honeybees on orchids’ pollination. We then present a study case from Australian orchids, testing the extent to which introduced honeybees can successfully pollinate orchids across different degrees of habitat alteration, using Diuris brumalis and D. magnifica (Orchidaceae). Globally, Apis mellifera is the principal alien bee potentially involved in orchid pollination. We show that pollinator efficiency and fruit set in D. brumalis is higher in wild habitats in which both native bees and invasive honeybees are present, relative to altered habitat with introduced honeybees only. Pollen removal and fruit set of D. magnifica rise with native bees’ abundance whilst pollinator efficiency decreases with honeybee abundance and increases with habitat size. Complementarily to our findings, our literature survey suggests that the presence of introduced honeybees adversely impacts orchid pollination, likely via inefficient pollen transfer. Given the worldwide occurrence of introduced honeybees, we warn that some orchids may be negatively impacted by these alien pollinators, especially in altered and highly fragmented habitats where natural pollination networks are compromised.

habitat alteration

introduced honeybees

invasive species

orchids

pollination

native bees

Biological invasions are one of the leading threats to global biodiversity (Bellard et al. 2016), impacting the structure and dynamics of landscapes, communities, and ecosystems (Traveset and Richardson 2014). The cascade effect of alien species can adversely affect mutualistic relationships among plant and animals, including pollination (Traveset and Richardson 2014). Particularly, invasive bees can change the original plant-pollinator network and even harm both partners (Agüero et al. 2020). By competing with native pollinators for floral resources and nesting sites (Goulson 2003; Agüero et al. 2018; Thomson and Page 2020), invasive bees can impact pollinator fitness and population dynamics (Thomson, 2004; Paini & Roberts, 2005; Hudewenz and Klein 2015). Through altering pollen flow, alien pollinators are expected to compromise plant reproductive success (Dohzono and Yokoyama 2010), limit pollen availability to native pollinators (Do Carmo et al. 2004; Traveset and Richardson 2014; Dohzono and Yokoyama 2010) and increase heterospecific pollen deposition (Traveset and Richardson 2014; Marrero et al. 2016).

European honeybees (Apis mellifera) have become principal floral visitors of plant species of ecosystems around the world (Herrera 2020), but their effect on plant reproductive success is complex to detect (Page and Williams 2023) and to assess (Agüero et al. 2020). Honeybees are generalist pollinators and frequent plant visitors but may not necessarily benefit plant reproduction of all species (Ollerton et al. 2012), especially when they competitively replace native pollinators and become ineffective surrogates (Page et al. 2021). Conversely, in cases where native pollinators are rare or locally extinct, honeybees often boost pollination (Lomov et al. 2010; Hanna et al. 2013) or can even recover plant fitness from reproductive collapse in fragmented habitat (Dick 2001). However, most studies have documented how honeybees impact native bee communities through floral resource competition, whilst their effect on plant reproduction remains poorly documented (Agüero et al. 2020; Page and Williams 2023).

Orchids present highly specialised pollination mechanisms, and therefore the impact of invasive honeybees on the fitness of these plants might be important. Beyond their renowned diversity of pollination systems, orchids can attract pollinators with nonrewarding flowers via various modes of deception (Van der Pijl and Dodson 1966; Dressler 1981; Dafni 1984; Schiestl 2005; Jersáková et al. 2006). About 46% of all orchid species globally are thought to lack reward (Shrestha et al. 2020; Ackerman et al. 2023), typically resulting in lower insect visitation rates compared to rewarding ones (Scopece at al. 2010; Brundrett 2019), deserving careful consideration for their conservation biology. Being that orchids offer pollen in discrete pollinia, instead of unpacked pollen dust as occurs in other flowering plants, is even more important to maximise the pollen transfer and deposition among flowers during pollinator visits (Johnson and Edwards 2000). A measure of the effectiveness of pollen transfer is pollination efficiency (PE) that is typically measured as the ratio of pollinated flowers on flowers with pollinia removed (Johnson et al. 2004; Tremblay et al. 2005). During transfer by pollinators, pollen losses in orchids are expected to be high when mediated by generalist pollinators and pollinator types overlap (Cozzolino et al. 2005; Scopece et al. 2010). For these reasons, pollinator efficiency in orchids might be hampered by exotic and generalist honeybees that manage to collect the pollinia but are not morphologically configurated to successfully deposit the pollinia and guarantee reproduction of the plant. Whilst in most cases pollinia removal and fruit set are similar across populations (Schemske 1980; Ackerman and Montalvo 1990; Proctor and Harder 1995; Li et al. 2011), in some orchid species these trends can diverge. For example, the food deceptive Australian orchid species Diuris brumalis and D. magnifica show diverse raise of male and female pollination success in relation to model plants’ abundance, with the first according to an exponential growth and the second to a logarithmic growth (Scaccabarozzi et al. 2018; Scaccabarozzi et al. 2020). However, studies on evaluating the effect of introduced honeybees on orchid pollination success are very scarce.

Here, we test whether orchid pollination success varies in response to the co-occurrence of introduced and native bees. To do that, our study focuses on two orchids’ species of genus Diuris (Orchidaceae) with analogous pollination strategies (food deception) but occupying different habitats that are subject to different human alteration degrees. Both species are pollinated by native bees of the genus Trichocolletes and are occasionally visited by the introduced Apis mellifera that potentially acts as a sub-optimal pollinator (Scaccabarozzi et al. 2018, 2020). In fact, whilst Apis mellifera is ubiquitarian in all study sites, the occurrence of native bees (Trichocolletes) is often discontinuous across the sites. Given that pollination success for D. brumalis varies according to habitat type (forest vs disturbed woodland; Scaccabarozzi et al. 2018), and for D. magnifica varies according to habitat size (Banksia woodland; Scaccabarozzi et al. 2020), our hypothesis focussed on the occurrence of native pollinators for D. brumalis and native pollinator abundance for D. magnifica. We expected that pollinia removal i) differed significantly in D. brumalis relative to the occurrence of native pollinators; and ii) increased in D. magnifica relative to native pollinators abundance. We also tested whether honeybees’ interaction with native pollinators augmented the orchid fruit set by confirming that fruit set was higher iii) in D. brumalis in sites where native pollinator co-occurred with honeybees and iv) in D. magnifica increased relative to native pollinator abundance. Lastly, we predicted that PE v) was higher in D. brumalis in sites with native pollinators across habitat types (forest vs disturbed woodland); vi) increased in D. magnifica with habitat size and vii) decreased with higher density of introduced honeybees. To contextualise and complement our study case, we provide an overview of incidence of honeybees in orchid pollination, with a focus on introduced honeybee potentially pollinating native and alien orchid species.

2.1 Literature survey: incidence of honeybees in pollination of orchids

We searched the global literature to identify and summarise studies in which native and introduced honeybees have been reported as potential pollinators in orchid species. In Google Scholar and Web of Science Core Collection we searched the the following key words: ‘Apis’, ‘pollinat’, ‘visitor’ and ‘honeybee’ and ‘orchid’. The first search was conducted on 1 July 2022 and repeated on 1 March 2023 any paper that mentioned an orchid-honeybee interaction was included. In addition, we included a book, co-authors’ photos, and personal observations in which invasive honeybees were reported as a substitute potential pollinator of Australian orchid species. During the survey, the introduced honeybee was recorded as a visitor (V, when only observed landing on a flower); successful pollinator (SP, when successfully pollinating the flowers at least once) or potential pollinators (PP, when removing pollinia at least once).

2.2 Study species

Diuris (Orchidaceae) comprises approx. 120 species distributed principally in Australia, with centres of diversity in south-western and south-eastern Australia (Backhouse et al. 2019). Diuris are terrestrial geophytes, producing a solitary scape per plant yearly (Jones, 2006); most species within the genus seem capable of clonal reproduction through vegetative propagation of tubers (Dixon et al.1989). We selected two species, Diuris brumalis and D. magnifica, with known pollination strategy and published reproductive data (Scaccabarozzi et al. 2018, 2020). Apis was observed to act as a potential pollinator of both species (Fig. 2, a-e).

Endemic to southwestern Australia, Diuris brumalis, is very common in Perth city area, and produces yellow brown nectar less flowers during July and August, with between three and 15 flowers per inflorescence (Hoffman and Brown 2011). Diuris magnifica is endemic to the Swan Coastal Plain in Western Australia, with its main distribution centred on the Perth metropolitan area (Fig. 1; Hoffman and Brown 2011). Flowering occurs from late winter to early spring, with between three and nine yellow-purple flowers per inflorescence (Hoffman and Brown 2011). Given the species were visited by introduced honeybees and occupied two different habitats, subject to anthropogenic alteration, they were chosen as model species to test for our hypothesis.

2.3 Study sites

We studied 14 populations of D. brumalis in the Darling Range, near Perth in Western Australia (Fig. 1). The populations were selected across two different habitat types: Jarrah Forest (hereafter referred to as ‘forest’) dominated by Eucalyptus marginata with Corymbia calophylla and open Jarrah Forest with Eucalyptus marginata and Allocasuarina fraseriana highly subject to fragmentation because of urbanization (hereafter referred to as ‘disturbed woodland’). Populations of D. magnifica were distributed across 15 sites in bushland remnants within the metropolitan area of the city of Perth (Fig. 1). Habitat was uniform across populations and characterised by Banksia woodland, an ecological community adjacent to the Swan Coastal Plain of Perth with a tree layer of Banksia with scattered Eucalyptus or Allocasuarina species and a diverse understorey including sclerophyllous shrubs, graminoids and forbs. Both the orchid species co-flowered with a range of Faboideae that represent a conspicuous component of the understorey vegetation.

2.4 Orchid pollination success

Pollination success data come from previously published studies (Scaccabarozzi et al. 2018; Scaccabarozzi et al. 2020, for D. brumalis and D. magnifica respectively). Additional data was included to increase the sample size for D. magnifica adding two populations. For D. brumalis the proportion of flowers with pollinia removal and the proportion of pollinated flowers at the end of the flowering period (i.e., the number of flowers found with at least one pollen massula on the stigma) was quantified in 2016 and in 2017, using a 30 × 30 m quadrat centred on each population. As per D. brumalis, at the end of flowering period in 2017, the proportion of D. magnifica flowers with pollinia removal and the proportion of pollinated flowers was recorded.

2.5 Observational transects on pollinator occurrence

We carried out observation along transects of 100 m length for 10 sites (populations) in September 2016 and 14 sites in September 2017 during D. brumalis flowering. We recorded the occurrence of native pollinator, Trichocolletes spp. (Colletidae) bees, the introduced honeybee by observing all the flowering species of the understory vegetation along the transect (Fig. 2a-e) and habitat type. Transects were centred on the same quadrats used to quantify pollination success of D. brumalis (see next paragraph). Observations along transect lasted 40 min, spending approximately 3 min per flowering plant. Transects were repeated one week after the initial survey, following the same route. For D. magnifica we carried out two observation transects for all the bushland reserves, from 5 to 15 September 2017, by recording the frequency (number of insects) of native pollinator, Trichocolletes spp. bees, and the introduced honeybee per 3 min of observation per flowering plant. Beetles were included too since they have been observed to act as sub-optimal pollinator in 2015 by extracting the pollinia and depositing it on the stigma of same orchid flower on two occasions (Scaccabarozzi et al. 2020). Sizes of bushland reserves were obtained from Scaccabarozzi et al. (2020). To quantify the effectiveness of pollen transfer, we calculated pollination efficiency (PE) for each population of both species as a ratio of pollinated flowers on flowers with pollinia removed (Johnson et al. 2004; Tremblay et al. 2005). PE was expressed as a ratio of Fp/Fr where Fp is the number of pollinated flowers and Fr is the number of flowers found with one or both pollinia removed. The value of PE potentially ranges between 0 and 1, with 1 representing the maximum and 0 the lowest efficiency.

2.6 Statistical analysis

We analysed the relationship between the proportion of pollinia removed, proportion of fruits, and pollination efficiency with the following independent variables via generalised linear mixed models: co-occurrence of honeybees and native bees, lack of co-occurrence (for D. brumalis), and abundance of honeybees and abundance of native bees (for D. magnifica). Year was included in each model as a fixed factor, while population was included as a random effect to account for repeated measures over time.

We also evaluated the effect of pollinator occurrence and year on the proportion of pollinia removed, on the proportion of fruit set and on the overall pollination efficiency in D. brumalis. To do so, we employed generalized linear regression models with binomial or quasi-binomial distributions of the response variables, depending on the overdispersion parameter. We firstly evaluated the role of the factor sampling site on the response variables to avoid possible data dependency. Regression models were evaluated for collinearity among covariates using the VIF criterion (VIF < 3). All the models were subjected to a backward regression approach to remove non-significant variables through the AICc criterion (delta AICc > 3). For D. magnifica we wanted to assess the effect of habitat size on orchid pollination success (pollinia removed and fruit set) and pollination efficiency. To do so, we tested the effects of number of plants, native and honeybee abundance, beetle abundance, and remnant size on the same response variables analysed for D. brumalis. The statistical analyses followed the same workflow described above. Furthermore, the relationship between remnant size and native bee abundance was evaluated through a negative binomial GLM to account for the overdispersion of the residuals occurring in the Poisson model. All the analyses were carried out in R ver 4.2.0 (R Core Team 2022) exploiting the following packages “ggplot2” (Wickham 2016), “plyr” (Wickham 2011), “MuMIn” (Barton 2009), “mass” (Venables and Ripley 2002).

3.1 Incidence of honeybees in pollination of orchids

A total of 82 publications were included in the literature survey, covering 65 different orchid species overall (see Table, Fig. S1) that were potentially pollinated by native or introduced honeybees. These included all continents where orchids occur, except Africa. Asia represented the 35% of total cases, followed by Europe (34%), Oceania (18%) and America (14%) (Fig. S2). Honeybee pollination (or potential pollination) was recorded most often for the Orchidoideae, followed by Epidendroideae subfamily and Cypripedioideae. Cymbiudium was the most frequently reported genus, with 14 species documented as pollinated (or potentially pollinated) by Apis cerana (Fig. S2). The introduced honeybee was observed to act as a: visitor (V, when only observed landing on a flower) for five orchid species; a successful pollinator (SP, when successfully depositing a pollinia at least once) in seven cases or potential pollinators (PP, when removing pollinia at least once) in 15 cases. Apis mellifera was the main alien bee involved in orchid pollination, occurring across 25 documented cases whilst the Africanized honeybee (hybrid) has been recorded twice as an alien species. In a few cases, A. mellifera was accompanied by other introduced bee genera such as Bombus, Centris and Euglossa.

3.2 Orchid pollination in relation to occurrence of native and alien honeybees

We found an overall effect of sampling year on pollinia removal and fruit set. In detail, the pollinia removal was higher in 2017 (χ2 = 7.4677, p = 0.006), whilst the fruit set was higher in 2016 (χ2 = 4.6356, p = 0.03). For D. brumalis, the occurrence of honeybees alone and the co-occurrence of honeybees and the native bees did not impact the pollinia removal (Fig. 3a) (χ2 = 2.8637, p = 0.091), but significantly impacted the fruit set (χ2 = 5.4698, p = 0.019) with lowest values where native bees lacked (Fig. 3b). Pollination efficiency was significantly lower where native bees were missing (disturbed woodland) relate to sites in which occurred with honeybees (forest) (χ2 = 6.1869, p = 0.012) (Fig. 3c).

With respect to D. magnifica, the abundance of native bees was associated with a significant increase in both pollinia removal (χ2 = 19.572, p < 0.001) and fruit set (χ2 = 5.1371, p = 0.023) (Fig. 4a, b; Table S1). In particular, the abundance of honeybees led to a decrease of pollination efficiency (χ2 = 7.2195, p = 0.007) (Fig. 4c; Table S1), whilst abundance of native bees did not affect pollination efficiency (Table S1). Overall pollination efficiency resulted lower in 2017 (χ2 = 4.1719, p = 0.04) (Fig. 4c; Table S1).

3.3 Effect of habitat type and size on pollination success and efficiency

In D. brumalis populations, as honeybees alone were found in disturbed woodland only, while honeybees and native bees occurred together in forest habitat, habitat type reflected the same effect on pollinia removal, fruit set and pollination efficiency than pollinator occurrence (Fig. 2a, b, c). Consequently, disturbed woodland had lower fruit set than forest. In D. magnifica populations, habitat remnant size was correlated with of pollination efficiency (χ2 = 6.7399, p = 0.009) with a positive logarithmic trend (Fig. 5).

Our study combined an analysis of experimental data on Diuris reproductive success with a literature survey that addresses the role of introduced honeybees in orchid pollination. We also examined whether alien honeybees adversely affect pollination success or have the capacity to support orchid pollination in altered landscapes.

4.1 Introduced honeybees likely impacting orchid pollination globally

The role of introduced honeybees, as a pollinator (or potential) for orchid species remains unresolved since most studies on interactions between introduced and native bees have focused on other plant families. In our literature survey, Apis mellifera was the principal potential alien bee involved in orchid pollination (Table 1). Pollination by honeybees (native and introduced) is not really common in orchid species, resulting in only 65 documented cases, in marked contrast with the prevalence of specialized pollination by the other corbiculate Apidae (orchid bees, bumblebees and stingless bees) which are known to be the primary pollinators of numerous orchid species (van der Pijl and Dodson 1966; van der Cingel 1995, 2001). This is unexpected given the widespread distribution of honeybees in Eurasia and Africa (Michener 2007), but in line with the relatively specialised pollination strategies of most orchids that often involve specific foragers rather than super-generalist pollinators as honeybees (Valido et al. 2019). Even though honeybees are the most frequently observed native pollinator of Mediterranean orchids, due to their omnipresence, but none of these species specializes on this pollinator (Joffard et al. 2019). Pollination by introduced honeybee is especially widespread among Cymbidium and Cypripedium species, in Asia and America respectively, and quite frequent among the North-Centre American Cyrtopodium (Table 1). In these cases, the introduced honeybees have a large body, comparable or even larger in size to Apis (i.e, Bombus, Trichocolletes, Megachile) (De Luca and Vallejo-Marin 2013; Scaccabarozzi et al. 2020; Table 1). Therefore, a prerogative of an alien surrogate pollinator seems to be the level of morphological fit between the alien bee and the newly acquired flower.

Table 1

Literature survey presenting the incidence of *Apis mellifera* as a native and alien species in orchid pollination across continents, according to the following categories: V: visitor; PP: potential pollinator; SP: successful pollinator. Personal observations and photos are included to support some evidence focusing on Australian orchid species.
Continent	Country	Subfamily	Plant species	Native or alien plant species	Native bee or other native pollinators	Introduced bee species	Pollination by introduced species	Literature source
Europe	Israel	Orchidoideae	Anacamptis collina	native	Apis mellifera	-	-	Dafni and Ivry 1979
Europe	Israel	Orchidoideae	Anacamptis fragrans	native	Vespula vulgaris, Xylocopa iris, Zygaena grasilini (Lepidoptera), Apis mellifera	-	-	Dafni and Ivry 1979
Europe	Austria and South of Italy	Orchidoideae	Anacamptis morio	native	Bombus sp., Apis mellifera, Andreana sp., Eucera sp. and other bees	-	-	Vöth 1987; Cozzolino et al. 2005
Europe	Greece	Orchidoideae	Anacamptis papilionacea	native	Apis mellifera, Nomada sp., Osmia sp., Eucera sp.	-	-	Vöth 1989
Europe	Austria	Orchidoideae	Anacamptis pyramidalis	native	Apis mellifera, Zygaena purpuralis	-	-	Vöth 1999
America	Puerto Rico	Epidendroideae	Arundina graminifolia	native	Megachile yaeyamaensi, Thyreus takaonis	Africanized honeybee (hybrid)	PP	Sugiura 2014; Ackerman 2021
Asia	Japan, South Korea	Epidendroideae	Bletilla striata	native	likely Tetralonia nipponensis	Apis mellifera	SP	Sugiura 1995; Ogawa and Takashi, 2020; Chung and Chung 2005
America	Chile, Argentina Andes	Orchidoideae	Brachystele unilateralis	native	Bombus dahlbomii	Apis mellifera, Bombus terrestris, Bombus ruderatus	SP	Sanguinetti and Singer 2014
Asia	China	Epidendroideae	Bulbophyllum ambrosia	native	Apis cerana	-	-	Chen and Gao 2011
Oceania	Western Australia	Orchidoideae	Caladenia flava	native	Neophyllotocus, native bee	Apis mellifera	V	Adams and Lawson 1993; Fig S1 and Daniela Scaccabarozzi personal observation
Oceania	Western Australia	Orchidoideae	Caladenia xantha	native	n.a.	Apis mellifera	V	Figure S1
Asia	Japan	Epidendroideae	Calanthe discolor	native	Apis cerana japonica, Eucera nipponensis, Osmia cornifrons	-	-	Suetsugu and Fukushima 2014
Asia	China	Epidendroideae	Changnienia amoena	native	Bombus tritasciatus, likely Apis cerana	-	-	Sun et al. 2003
America	Chile, Argentina Andes	Orchidoideae	Chloraea virescens	native	Bombus dahlbomii	Apis mellifera, Bombus terrestris, Bombus ruderatus	SP	Sanguinetti and Singer 2015
Asia	Nepal	Epidendroideae	Coelogyne flaccida	native	Apis cerana	-	-	Subedi et al. 2011
Asia	Nepal	Epidendroideae	Coelogyne nitida	native	Apis cerana	-	-	Subedi et al. 2011
Asia	India	Epidendroideae	Cymbidium aloifolium	native	Apis cerana indica	-	-	Adit et al. 2022
Asia	Japan	Epidendroideae	Cymbidium dayanum	native	Apis cerana japonica	-	-	Matsuda and Sugiura 2019
Asia	Nepal, Sikkim, Bhutan, and North Thailand	Epidendroideae	Cymbidium devonianum	native	Apis cerana japonica	-	-	Sugahara 2006
Asia	Borneo, Malesia	Epidendroideae	Cymbidium finlaysonianum	native	Apis cerana		-	Chan et al. 1994; Ong 2010
Asia	Japan	Epidendroideae	Cymbidium floribundum	native	Apis cerana japonica	-	-	Sugahara et al. 2013; Sugahara et al. 2010; Sasagawa et al. 2005
Asia	China	Epidendroideae	Cymbidium goeringii	native	Apis cerana	-	-	Yu et al. 2008
Asia	Japan	Epidendroideae	Cymbidium goeringii	native	Apis cerana japonica	-	-	Tsuji and Kato 2010
Asia	Japan	Epidendroideae	Cymbidium kanran	native	Apis cerana japonica	-	-	Tsuji and Kato 2010
Asia	China	Epidendroideae	Cymbidium lancifolium	native	Apis cerana	-	-	Cheng et al. 2007
Asia	Japan	Epidendroideae	Cymbidium lancifolium	native	likely Apis cerana cerana	-	-	Suetsugu 2015
Asia	Japan	Epidendroideae	Cymbidium macrorhizon	native	Apis cerana cerana	-	-	Suetsugu 2015
Asia	India	Epidendroideae	Cymbidium pendulum	native	Apis cerana	Apis mellifera	SP	Attri and Kant 2011; Jagdeep et al. 2012; Verma et al. 2012
Asia	Japan	Epidendroideae	Cymbidium pumilum	alien	Apis cerana japonica	western honeybee not attracted	-	Sasaki et al. 1991
Asia	China	Epidendroideae	Cymbidium qiubeiense	native	Apis cerana cerana	-	-	Hu et al. 2018
Asia	Myanmar	Epidendroideae	Cymbidium suavissimum	native	Apis cerana japonica	-	-	Sugahara 2006
America	USA	Cypripedioideae	Cypripedium candidum	native	likely Andrena sp., Odontomyia pubescens (Diptera)	Apis mellifera	PP	Pearn 2013; Grantham et al. 2018
America	USA	Cypripedioideae	Cypripedium parviflorum	native	likely Andrena sp., Odontomyia pubescens (Diptera), Lasioglossum zonulum	Apis mellifera	PP	Pearn 2013; Grantham et al. 2019
America	USA, Canada	Cypripedioideae	Cypripedium reginae	native	likely Anthophora; Megachile spp.	Apis mellifera	PP	Edens Meier et al. 2011
America	Mexico	Epidendroideae	Cyrtopodium macrobulbon	native	likely Centris or Xylocopa	Apis mellifera	PP	Miranda-Molina et al. 2021
Asia	China	Epidendroideae	Cyrtopodium polyphyllum	alien	Centris tarsata; Centris labrosa	Apis mellifera, Centris nitida, Centris errans	PP	Liu and Pemberton 2010; Pansarin et al. 2008
America	Florida, USA	Epidendroideae	Cyrtopodium punctatum	native	Xylocopa sp.	Apis mellifera, Euglossa viridissima, Centris errans	V	Ackerman 1955; Pemberton and Liu 2008; Dutra et al. 2009
Europe	Poland	Orchidoideae	Dactylorhiza majalis	native	Apis mellifera	-	-	Ostrowiecka et al. 2019
Europe	France	Orchidoideae	Dactylorhiza majalis	native	Bombus sp., Apis mellifera	-	-	Berger 2003
Europe	Sweden	Orchidoideae	Dactylorhiza sambucina	native	Bombus sp., Osmia bicolor, Apis mellifera	-	-	Nilsson 1980
Europe	Poland and England	Orchidoideae	Dactylorhiza spp. (D. incarnata, D. fuchsii and D. majalis)	native	Apis mellifera	-	-	Wroblewska et al. 2019; Ostrowiecka et al. 2019; Dafni and Woodell 1986
America	Puerto Rico	Epidendroideae	Dendrobium crumenatum	alien	Apis cerana	Africanized honeybee (hybrid)	PP	Leong and Wee 2013; Meurgey 2017; Ackerman 2017
Oceania	Eastern Australia	Epidendroideae	Dendrobium kingianum	native	n.a.	Apis mellifera	PP	Figure S1
Oceania	Australia	Epidendroideae	Dendrobium speciosum var. hillii	native	likely Trigona sp., Homalictus sp., Lassioglossum, Hylaeus	Apis mellifera	V	Slater and Calder 1988
Oceania	Western Australia	Orchidoideae	Diuris brumalis	native	Tichocolletes capillosus, Trichocolletes leucogenys	Apis mellifera	PP	Scaccabarozzi et al. 2018
Oceania	Eastern Australia	Orchidoideae	Diuris maculata	native	Trichocolletes venustus	Apis mellifera	SP	Beardsell et al. 1986; Indsto et al. 2006
Oceania	Western Australia	Orchidoideae	Diuris magnifica	native	Tichocolletes gelasinus, T.dives	Apis mellifera	SP	Scaccabarozzi et al. 2019
Oceania	Australia	Orchidoideae	Diuris sulphurea	native	Paracolletes sp., Amegilla sp., Lipotriches sp.	Apis mellifera	PP	Rayment 1932; Fig. S1
Europe	Sweden	Epidendroideae	Epipactis palustris	native	Apis mellifera, Andrena sp., Lassioglossum sp., Bombus and other insects	-	-	Nilsson 1978
Europe	Poland and Czech	Epidendroideae	Epipogium aphyllum	native	Apis mellifera	-	-	Jakubska-Busse et al. 2014
Europe	Czech Republic & Poland	Epidendroideae	Epipogium aphyllum	native	Apis mellifera, Bombus sp.	-	-	Jakubska-Busse et al. 2014
Asia	China	Epidendroideae	Epipogium roseum	native	Apis cerana cerana	-	-	Zhou et al. 2012
Asia	China	Epidendroideae	Eria coronaria	native	Apis cerana	-	-	Shangguan et al. 2008
Oceania	Western Australia	Orchidoideae	Eriochilus dilatatus	native	Halictidae	Apis mellifera	PP	Bundrett 2014; Daniela Scaccabarozzi personal observation
Asia	China	Orchidoideae	Goodyera foliosa	native	Apis cerana	-	-	Zha et al. 2016; Liu et al. 2020
Europe	Germany	Orchidoideae	Goodyera repens	native	Bombus sp., Lassioglossum sp., Apis mellifera	-	-	Vöth 1999; Classens and Kleynen 2013
Europe	France	Orchidoideae	Gymnadenia corneliana	native	Apis mellifera, Colias phicomone (Lepidoptera), Erebia alberganus (Lepidoptera)	-	-	Berger 2009
Europe	Austria	Orchidoideae	Himantoglossum adriaticum	native	Apis mellifera, Colletes similis	-	-	Vöth 1999
Europe	Hungary	Orchidoideae	Himantoglossum adriaticum	native	Apis mellifera (Apiary)	-	-	Biro et al. 2014
Europe	Sweden	Orchidoideae	Neottia ovata	native	Apis mellifera and a broad range of insects	-	-	Nilsson 1981
Europe	Greek	Orchidoideae	Orchis boryi	native	Apis mellifera	-	-	Gumbert and Kunze 2001
Europe	Greece	Orchidoideae	Orchis italica	native	Apis mellifera, Chelostoma transversum, Anthidium septemdentatum	-	-	Vöth 1998
Europe	Austria	Orchidoideae	Orchis militaris	native	Apis mellifera, Andrea sp., Halictus sp., Osmia sp., Tropinota hirta (Coleoptera)	-	-	Vöth 1999
Europe	France	Orchidoideae	Orchis purpurea	native	Apis mellifera	-	-	Berger 2004
Oceania	Australia	Orchidoideae	Prasophyllum elatum	native	native bee	Apis mellifera	V	Figure S1
Oceania	Australia	Orchidoideae	Prasophyllum sp.	native	native bees and wasps	Apis mellifera	PP	Photo and personal observation by Rudie Kuiter Fig. S1
Oceania	Eastern Australia	Orchidoideae	Spiranthes australis	native	Amegilla asserta (likely primary pollinator);	Apis mellifera	PP	Ren personal observation; Kuiter 2023
Asia	Japan	Orchidoideae	Spiranthes australis	native	Megachile nipponica; M. japonica; Halictidae sp.	Apis mellifera	SP	Suetsugu and Abe 2021; Iwata et al. 2012
Europe	Ireland	Orchidoideae	Spiranthes romanzoffiana	native	Apis mellifera	-	-	Duffy and Stout 2008
Oceania	Australia	Orchidoideae	Spiranthes sinensis	native	guild of native bees	Apis mellifera	PP	Coleman 1933
Asia	China	Orchidoideae	Spiranthes sinensis	native	Apis cerana, Bombus sp., Ceratina, Halictidae	-	-	Tao et al. 2018
Europe	Greek	Orchidoideae	Spiranthes spiralis	native	Apis mellifera	-	-	Petanidou et al. 2013
Europe	NA	Orchidoideae	Spiranthes spiralis	native	Apis mellifera	-	-	Reinhard et al. 1991
America	USA	Orchidoideae	Spiranthes vernalis	native	native bee	Apis mellifera	PP	Catling 1983
Europe	Austria	Orchidoideae	Traunsteinera globosa	native	Bombus sp., Lassioglossum sp., Apis mellifera and other insects	-	-	Vöth 1994

Our literature search shows that in most of cases the introduced honeybee was ineffective in replacing native pollinators. There were 25 recorded cases where introduced honeybees were observed as a visitor or a potential pollinator but in only seven cases they were recorded as a pollinator. However, none of these cases except our study case has investigated the impact of introduced honeybees on the orchid pollination efficiency or the frequency of their pollination events.

4.2 Orchid pollination success and efficiency in relation to occurrence of native and alien honeybees

In our empirical study, western honeybees occurred in all study sites for both target species (D. brumalis and D. magnifica) whilst occurrence of native bees (Trichocolletes spp.) was erratic across sites. In D. brumalis, honeybees predominantly occurred along with native bees in the genus Trichocolletes (Scaccabarozzi et al. 2018), but in the absence of native bees, orchid fruit set had the lowest values (Fig. 3b). Notably, there was no difference on orchid pollinia removal between sites where honeybees occurred alone and sites where it co-occurred with native bees (Fig. 3a), indicating that honeybees led to comparable level of pollinia removal to native bees. Thus, honeybees are capable of successfully removing pollinia from flowers of D. brumalis (Fig. 3, a, b, c, d), but since fruit set and pollination efficiency were lowest when honeybees occurred alone, we hypothesise that they deplete pollen supplies available to native pollinators (Ackerman 2021) and fail to be effective at pollen deposition. This highlights the value of native pollinator specificity in orchid pollen deposition. According to the lock and key hypothesis food deceptive species showed higher levels of correlation between pollinarium and stigmatic cavity lengths comparing to sexual deceptive species (Lussu et al. 2019), to avoid heterospecific pollen deposition of sympatric species, so that pollinator specificity is very crucial in food deceptive species.

In D. magnifica both male and fruit set exponentially raised with native bee abundance (Trichocolletes gelasinus; Fig. 4a, b) and they were not impacted by the abundance of Apis mellifera along study sites. The output was similar among pollinia removal and fruit set and conforms with our expectations that optimal pollinator frequency would enhance the orchid reproductive success.

Interestingly, in D. magnifica, the increasing of honeybees abundance inversely influenced the orchid pollination efficiency likely because they withdraw pollinia without successfully depositing them on the next flower (Fig. 2, b, c, e; Fig. 4c; Arguero 2020; Ackerman 2021) as per in D. brumalis. However, the abundance of native bees did not influence the pollination success and PE for this species. This could be explained by the discontinuous occurrence of native bees across the bushland remnants, especially in smaller bushland reserves. It is also plausible that other factors might interfere with the ability of native pollinators to fulfil their pollination service, i.e., presence of suboptimal pollinators such as beetles, that were observed to remove pollinia and deposit it on the same flowers on few occasions (Scaccabarozzi et al. 2020) and competition between honeybees and wild bees for access to floral resources (Agüero et al. 2020; Page and Williams 2023). In addition, plant success often relies more on bee assemblage and diversity than abundance per se (Klein et al. 2003). However, the significant impact of honeybees’ abundance on D. magnifica pollination efficiency provided compelling evidence for the detrimental effect of honeybees’ abundance on orchid reproduction. Honeybee is well known for its modest efficiency in pollination service (Hung et al. 2018; Page et al. 2022) and in some cases is even possible to observe a shift from a mutualistic relationship between the plant and the pollinator to an antagonistic one where costs (i.e., associated with nectar replenishment or damage to flowers) exceed the benefits for the plant pollination (Aizen et al. 2014).

Findings here suggest an accurate and considered management of beekeeping activity that can influence the abundance of alien bees relate to native ones so reducing antagonistic costs for the plants. However, we intend to cautiously consider this hypothesis because our study sites did not include orchid populations with native bees only. To test for the effect of native bees and introduced honeybees on orchid pollination and if this latter is influenced by resource overlap between native and introduced bees more conclusively, would be necessary to i) isolate the effects of native bee occurrence from honeybee occurrence (this may not be feasible since honeybees are often ubiquitous); ii) test if a lack of native bees is primarily caused by habitat change or competition with honeybees, and iii) investigate honeybee abundance in intact and altered habitat respectively.

4.3 Effect of habitat type and size on pollination success and efficiency

Habitat type influenced the orchid reproductive success in D. brumalis. but habitat type (wild vs disturbed) also influenced the co-occurrence of honeybees and native bees (Fig. 3, b, c), since only honeybees occurred in disturbed woodland. Diuris brumalis pollination success was highest with the occurrence of native bees and lowest with honeybees only.

We were not able to determine the causes of lack of native pollinators in some of the study sites, but we hypothesize that anthropogenic habitat alteration (disturbance linked to urban development) might have led to their decline (Potts et al. 2010; Scheper et al. 2014). Given that Trichocolletes native bees are ground-nesting bees (Houston et al. 2023), habitat change might interfere with nesting and foraging sites (Goulson et al. 2005; Biesmeijer et al. 2006; Baude et al. 2016), eventually leading to their local loss. Species that employ Batesian floral mimicry as D. brumalis have specialised pollination and rely on few pollinator types (Scaccabarozzi et al. 2018). These outcomes point the attention on the conservation of bee fauna in land use and management especially for crucial pollinators of rare species and highly specific pollinators. For D. magnifica, larger bushland reserves led to an increase of pollination efficiency (Fig. 5). Specifically, the growth was sharp in the first half of the predicted trend, where values from 0 to 0.5 PE were linked to habitats within a range of 1–60 ha. This means that even relatively small bush fragments can sustain an effective pollination service. However, only bigger bushland reserves (over 100 ha) showed PE > 0.5, suggesting that the continuous habitat provided a more optimal pollination service. This trend might be explained by the expectation that larger habitat sizes sustain a higher biodiversity of native bees (number and richness) (Blaauw & Isaacs, 2014).

We empirically show that Diuris pollination was impacted by the interplay between exotic bees and native bees. In D. brumalis the pollination efficiency (PE) was higher in the wild habitat where native and alien honeybees co-occurred and was lower in the altered habitats with only introduced honeybees. Pollination efficiency was also positively impacted by habitat type and size respectively for D. brumalis and D. magnifica. Because many members of the orchid family are at high risk of extinction, resolving their pollination status in areas occupied by introduced honeybees is vital for their conservation through effective land management. Our study provides evidence that biological invasion by honeybees can impact orchid pollination efficiency and that this effect is exacerbated by habitat disturbance. Given that European honeybees have occupied all continents except Antarctica and are the primary alien bees involved in orchid pollination, our literature survey highlights the importance on conducting studies on the interaction of native and alien pollinator species globally. Our findings recommend an accurate and considered management of beekeeping activity such as introduction of honeybees to new areas, carefully determining the minimum distance of hives to orchid populations and monitoring the number of honeybees relative to native bees in the sites where hives are located. This knowledge is required for ensuring the survival of many orchid species, especially where the habitat is altered and highly fragmented and the effect of honeybees on orchid reproductive success is most severe.

Supplementary material

Supplementary material associated with this article includes Figure S1, Figure S2, Table S1 and Datafile S1.

Acknowledgments

We thank Rudie Hermann Kuiter for providing photos to complement the literature survey with documented observations, Massimo Labra and Andrea Galimberti for supporting the statistical analysis.

Funding

We thank the Endeavor Fellowship Program [5117_2016] and the Università degli Studi di Napoli Federico II via Short Mobility Program [D.M. 976_2017] for financial support during data acquisition.

Competing interests

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Author contribution

Daniela Scaccabarozzi, Zong-Xin Ren, Salvatore Cozzolino contributed to the study conception and design. Material preparation, data collection, graphics and analysis were performed by Daniela Scaccabarozzi, Lorenzo Guzzetti, Emiliano Pioltelli, Andrea Aromatisi, Zong-Xin Ren, Mark Brundrett, Mario Vallejo-Marin and Giovanni Polverino. The first draft of the manuscript was written by Daniela Scaccabarozzi and all authors commented on previous versions of the manuscript. All authors read and approved the final manuscript.

Ackerman JD, Phillips RD, Tremblay RL, Karremans A, Reiter N, Peter CI, Bogarín D, Pérez-Escobar OA, Liu H (2023) Beyond the various contrivances by which orchids are pollinated: global patterns in orchid pollination biology. Bot J Linn Soc 202:295–324. https://doi.org/10.1093/botlinnean/boac082
Ackerman JD (2017) Orchidées invasives: accélération de la colonization et de la propagation. L’Orchidophile 213:167–173
Ackerman JD (2021) Island invasions by introduced honey bees: what can be expected for Puerto Rico and the Caribbean? Front Ecol Evol 8:556744. https://doi.org/10.3389/fevo.2020.556744
Ackerman JD, Montalvo AM (1990) Short-and long‐term limitations to fruit production in a tropical orchid. Ecol 71:263–272. https://doi.org/10.2307/1940265
Agüero JI, Rollin O, Torretta JP, Aizen MA, Requier F, Garibaldi LA (2018) Impactos de la abeja melífera sobre plantas y abejas silvestres en hábitats naturales. Ecosistemas 27:60–69. https://doi.org/10.7818/ECOS.1365
Agüero JI, Pérez-Méndez N, Torretta JP, Garibaldi LA (2020) Impact of invasive bees on plant-pollinator interactions and reproductive success of plant species in mixed Nothofagus Antarctica forests. Neotrop Entomol 49:557–567. https://doi.org/10.1007/s13744-020-00787-6
Adams PB, Lawson SD (1993) Pollination in Australian Orchids: a Critical-Assessment of the Literature 1882–1992. Aust J Bot 41:553–575. https://doi.org/10.1071/BT9930553
Adit A, Koul M, Choudhary AK, Tandon R (2022) Interaction between Cymbidium aloifolium and Apis cerana: Incidence of an outlier in modular pollination network of oil flowers. Ecol Evol 12:e8697. https://doi.org/10.1002/ece3.8697
Aizen MA, Morales CL, Vázquez DP, Garibaldi LA, Sáez A, Harder LD (2014) When mutualism goes bad: density-dependent impacts of introduced bees on plant reproduction. New Phytol e8697. https://doi.org/10.1002/ece3.8697
Attri LK, Kant R (2011) Orchid Pollination: an observation on pollination-pollinator interaction in Cymbidium pendulum (Sw.) Roxb. Curr Bot 2:05–08
Backhouse G, Bates RJ, Brown AP, Copeland LM (2019) A Checklist of the Orchids of Australia Including its Island Territories. Self-published, Melbourne. ISBN 978-0-9946489-3-8
Beardsell DV, Clements MA, Hutchinson JF, Williams EG (1986) Pollination of Diuris maculata R Br (Orchidaceae) by Floral Mimicry of the Native Legumes Daviesia spp and Pultenaea scabra R Br. Aust J Bot 34:165–173. https://doi.org/10.1071/BT9860165
Bellard C, Cassey P, Blackburn TM (2016) Alien Species as a Driver of Recent Extinctions. Biol Lett 12:20150623. https://doi.org/10.1098/rsbl.2015.0623
Berger L (2003) Observations sur le comportement de quelques pollinisateurs d’orchidées (2e partie) – L’Orchidophile 159:277–290
Berger L (2004) Observations sur le comportement da quelques pollinisateurs d’orchidées (3partie). – L’Orchidophile 160:19–35
Berger L (2009) La pollinisation du genre Nigritella (L.C.M. Richard). – J Europäischer Orchideen 41:411–432
Bíró E, Bodis J, Nagy T, Toekoelyi J, Molnar VA (2015) Honeybee (Apis mellifera) mediated increased reproductive success of a rare deceptive orchid. Appl Ecol Environ Res 13:181–192
Blaauw BR, Isaacs R (2014) Larger patches of diverse floral resources increase insect pollinator density, diversity, and their pollination of native wildflowers. Basic Appl Ecol 15:701–711. https://doi.org/10.1016/j.baae.2014.10.001
Brundrett M (2014) Identification and ecology of southwest Australian orchids. Western Australian Naturalists' Club Inc, Perth
Burton K (2009) Mu-Mln: Multi-model inference. R package, Version 0.12.2/r18. https://mumin.r-forge.r-project.org/
Catling P (1983) Pollination of northeastern North American Spiranthe (Orchidaceae). Can J Bot 61:1080–1093. http://dx.doi.org/10.1139/b83-116
Claessens J, Kleynen J (2013) Honigbienen (Apis mellifera) als Bestäuber von Goodyera repens. – J Europäischer Orchideen 45:133–138
Diller C, Castañeda-Zárate M, Johnson SD (2022) Why honeybees are poor pollinators of a mass-flowering plant: experimental support for the low pollen quality hypothesis. Am J Bot 109:1305–1312. https://doi.org/10.1002/ajb2.16036
Chen L, Gao J (2011) Reproductive ecology of Bulbophyllum ambrosia (Orchidaceae). Acta Pharmacol Sin 35:1202–1208. https://www.plant-ecology.com/EN/10.3724/SP.J.1258.2011.01202
Chan CL, Lamb A, Shim PS, Wood JJ (1994) Orchids of Borneo, volume 1: introduction and a selection of species. Sabah Society Kota Kinabalu, Kew, Royal Botanic Gardens, Kew, London
Chung MY, Chung MG (2005) Pollination biology and breeding systems in the terrestrial orchid Bletilla striata. Plant Syst Evol 252:1–9. https://doi.org/10.1007/s00606-004-0256-6
Coleman E (1933) Further notes on the pollination of Spiranthes sinensis (Pers.) Ames. Vic Naturalist 50:61–64
Cozzolino S, Schiestl FP, Müller A, De Castro O, Nardella AM, Widmer A (2005) Evidence for pollinator sharing in Mediterranean nectar-mimic orchids: absence of premating barriers? Proc Royal Soc B 272:1271–1278. https://doi.org/10.1098/rspb.2005.3069
Dafni A (1984) Mimicry and deception in pollination. Ann Rev Ecol Evol Syst 15:259–278. https://doi.org/10.1146/annur ev.es.15.110184.001355
Dafni A, Yariv I (1979) Pollination ecology of, and hybridization between Orchis coriophora L. and O. collina Sol. Ex Russ. (Orchidaceae) in Israel. New Phytol 83:181–187
Dafni A, Woodell SRJ (1986) Stigmatic Exudate and the Pollination of Dactylorhiza fuchsii (Druce) Soo. Flora 178:343–350. https://doi.org/10.1016/S0367-2530(17)31521-9
De Luca PA, Vallejo-Marín M (2013) What's the ‘buzz’about? The ecology and evolutionary significance of buzz-pollination. Curr Opin Plant Biol 16:429–435. https://doi.org/10.1016/j.pbi.2013.05.002
Dick WC (2001) Genetic rescue of remnant tropical trees by an alien pollinator. Proc R Soc B: Biol Sci 268:2391–2396. https://doi.org/10.1098/rspb.2001.1781
Dixon KW, Buirchell BJ, Collins MT (1989) Orchids of Western Australia: Cultivation and Natural History, 2nd edn. Western Australian Native Orchid Study and Conservation Group, Victoria Park, Perth
Do Carmo RM, Franceschinelli EV, da Silveira FA (2004) Introduced honeybees (Apis mellifera) reduce pollination success without affecting the floral resource taken by native pollinators. Biotropica 36:371–376. https://doi.org/10.1111/j.1744-7429.2004.tb00329.x
Dodson CH (1966) Ethology of some bees of the tribe Euglossini (Hymenoptera: Apidae). J Kans Entomol Soc 39:607–629. https://www.jstor.org/stable/25083566
Dohzono I, Yokoyama J (2010) Impacts of alien bees on native plant-pollinator relationships: a review with special emphasis on plant reproduction. Appl Entomol Zool 45:37–47. https://doi.org/10.1303/aez.2010.37
Dressler RL (1981) The orchids: natural history and classification. Harvard University Press, Cambridge
Duffy KJ, Stout JC (2008) The effects of plant density and nectar reward on bee visitation to the endangered orchid Spiranthes romanzoffiana. Acta Oecol 34:131–138. https://doi.org/10.1016/j.actao.2008.04.007
Dutra D, Kane ME, Adams CR, Richardson L (2009) Reproductive biology of Cyrtopodium punctatum in situ: implications for conservation of an endangered Florida orchid. Plant Species Biol 24:92–103. https://doi.org/10.1111/j.1442-1984.2009.00242.x
Edens-Meier R, Arduser M, Westhus E, Bernhardt P (2011) Pollination ecology of Cypripedium reginae Walter (Orchidaceae): size matters. Telopea 13:327–340
Goulson D (2003) Effects of introduced bees on native ecosystems. Ann Rev Ecol Evol Syst 34:1–26. https://doi.org/10.1146/annurev.ecolsys.34.011802.132355
Government of Western Australia (2000) Bush forever, policies, principles and processes, vol 1. Western Australian Planning Commission, Perth
Grantham MA, Ford BA, Worley AC (2019) Pollination and fruit set in two rewardless slipper orchids and their hybrids (Cypripedium, Orchidaceae): large yellow flowers outperform small white flowers in the northern tall grass prairie. Plant Biol 21:997–1007. https://doi.org/10.1111/plb.13026
Gumbert A, Kunze J (2001) Colour similarity to rewarding model plants affects pollination in a food deceptive orchid, Orchis boryi. Biol J Linn 72:419–433. https://doi.org/10.1111/j.1095-8312.2001.tb01328.x
Hanna C, Foote D, Kremen C (2013) Invasive species management restores a plant–pollinator mutualism in Hawaii. J Appl Ecol 50:147–155. https://doi.org/10.1111/1365-2664.12027
Henneresse T, Tyteca D (2016) Insect Visitors and Potential Pollinators of Orchis militaris (Orchidaceae) in Southern Belgium. J Insect Sci 16:104. https://doi.org/10.1093/jisesa/iew088
Herrera CM (2020) Gradual replacement of wild bees by honeybees in flowers of the Mediterranean Basin over the last 50 years. Proc Royal Soc B 287:20192657. https://doi.org/10.1098/rspb.2019.2657
Hoffman N, Brown A (2011) Orchids of south-west Australia, 3rd edn. University of Western Australia, Perth
Houston TF, Dods K, Milne LA, Scaccabarozzi D (2023) New insights into the unusual nesting biology of the bee Trichocolletes orientalis (Hymenoptera: Colletidae, Neopasiphaeinae), particularly its larval ‘oil bath’. Apidologie 54:11. https://doi.org/10.1007/s13592-022-00981-y
Hu S, Xin R, Guo H, Wang X, Zhang Z, Cheng J (2018) Accuracy detection of predicting pollinator from pollination syndromes: taking Cymbidium qiubeiense as an example. J Beijing for Univ 40:101–110
Hudewenz A, Klein AM (2015) Red mason bees cannot compete with honeybees for floral resources in a cage experiment. Ecol Evol 5:5049–5056. https://doi.org/10.1002/ece3.1762
Hung KLJ, Kingston JM, Albrecht M, Holway DA, Kohn JR (2018) The worldwide importance of honeybees as pollinators in natural habitats. Proc R Soc B: Biol Sci 285:20172140
Indsto JO, Weston PH, Clements MA, Dyer AG, Batley M, Whelan RJ (2006) Pollination of Diuris maculata (Orchidaceae) by male Trichocolletes venustus bees. Aust J Bot 54:669–679. https://doi.org/10.1071/BT05146
Iwata T, Nagasaki O, Ishii HS, Ushimaru A (2012) Inflorescence architecture affects pollinator behaviour and mating success in Spiranthes sinensis (Orchidaceae). New Phytol 193:196–203. https://doi.org/10.1111/j.1469-8137.2011.03892.x
Jakubska-Busse A, Jasicka-Misiak I, Poliwoda A, Święczkowska E, Kafarski P (2014) The chemical composition of the floral extract of Epipogium aphyllum Sw. (Orchidaceae): a clue for their pollination biology. Arch Biol Sci 66:989–998. 10.2298/ABS1403989B
Jersáková J, Johnson SD, Kindlmann P (2006) Mechanisms and evolution of deceptive pollination in orchids. Biol Rev 81:219–235. https://doi.org/10.1017/S1464793105006986
Jin C, Shiyong L, Rong H, Xinlian W, Yibo L (2007) Food-deceptive pollination in Cymbidium lancifolium (Orchidaceae) in Guangxi, China. Biodiv Sci 15:608–617. https://www.biodiversity-science.net/EN/ 10.1360/biodiv.070091
Joffard N, Massol F, Grenié M, Montgelard C, Schatz B (2019) Effect of pollination strategy, phylogeny and distribution on pollination niches of Euro-Mediterranean orchids. J Ecol. https://doi.org/10.1111/1365-2745.13013
Johnson SD, Edwards TJ (2000) The structure and function of orchid pollinaria. Plant Syst Evol 222:243–269. https://doi.org/10.1007/BF00984105
Johnson SD, Peter CI, Ågren J (2004) The effects of nectar addition on pollen removal and geitonogamy in the non-rewarding orchid Anacamptis morio. Proc R Soc B: Biol Sci 271:803–809. https://doi.org/10.1098/rspb.2003.2659
Klein AM, Steffan–Dewenter I, Tscharntke T (2003) Fruit set of highland coffee increases with the diversity of pollinating bees. Proc R Soc B: Biol Sci 270:955–961. https://doi.org/10.1098/rspb.2002.2306
Kuiter HR (2023) Orchid pollinators of Victoria. 5 Eds, Aquatic Photographics, Victoria, Australia
Leong TM, Yeow CW (2013) Observations of pollination in the pigeon orchid, Dendrobium crumenatum Swartz (Orchidaceae) in Singapore. Nat Singap 6:91–96
Li P, Huang BQ, Pemberton RW, Luo YB, Cheng J (2011) Floral display influences male and female reproductive success of the deceptive orchid Phaius delavayi. Plant Syst Evol 296:21–27. https://www.jstor.org/stable/43558601
Liu H, Pemberton R (2010) Pollination of an invasive orchid, Cyrtopodium polyphyllum (Orchidaceae), by an invasive oil-collecting bee, Centris nitida, in southern Florida. Botany 88:290–295. 10.1139/B10-017
Liu N, Xiao H, Chen X, Chi Y, Luo H, Xiong D, Yang B (2020) Nectar secretion characteristics and their effects on insect pollination of Goodyera foliosa, a nectar rewarding orchid. J Trop Subtrop Bot 28:265–270. https://doi.org/10.1007/s00606-011-0473-8
Lomov B, Keith DA, Hochuli DF (2010) Pollination and plant reproductive success in restored urban landscapes dominated by a pervasive exotic pollinator. Landsc Urban Plan 96:232–239. https://doi.org/10.1016/j.landurbplan.2010.03.009
Lussu M, De Agostini A, Cogoni A, Marignani M, Cortis P (2019) Does size really matter? A comparative study on floral traits in orchids with two different pollination strategies. Plant Biol J 21:961–966. https://doi.org/10.1111/plb.12993
Matsuda Y, Sugiura N (2019) Specialized pollination by honeybees in Cymbidium dayanum, a fall-winter flowering orchid. Plant Species Biol 34:19–26. https://doi.org/10.1111/1442-1984.12231
Marrero HJ, Medan D, Zarlavsky GE, Torretta JP (2016) Agricultural land management negatively affects pollination service in Pampean agro-ecosystems. Agric Ecosyst Environ 218:28–32. https://doi.org/10.1016/j.agee.2015.10.024
Meurgey F (2016) Bee species and their associated flowers in the French West Indies (Guadeloupe, Les Saintes, La Désirade, Marie Galante, St Barthelemy and Martinique) (Hymenoptera: Anthophila: Apoidea). Ann Soc Entomol Fr 52:209–232. https://doi.org/10.1080/00379271.2016.1244490
Miranda-Molina YM, Gonzalez EJ, Marquez-Guzman J, Meave JA, Perez-Garcia EA (2021) Pollination success in three tropical dry forest orchid species from Mexico: insights from floral display, visitation rates, and flower micromorphology. Bot Sci 99:771–790. https://doi.org/10.17129/botsci.2785
Nilsson LA (1978) Pollination ecology of Epipactis palustris (Orchidaceae). Bot Notiser 131:255–368
Nilsson LA (1980) The pollination ecology of Dactylorhiza sambucina (Orchidaceae). Bot Notiser 133:367–385
Ogawa Y, Miyake T (2020) How do rewardless Bletilla striata flowers attract pollinators to achieve pollination? Plant Syst Evol 306:78. https://doi.org/10.1007/s00606-020-01709-0
Ollerton J, Price V, Armbruster WS, Memmott J, Watts S, Waser NM, Totland Ø, Goulson D, Alarco R, Stout J, Tarrant S (2012) Overplaying the role of honeybees as pollinators: a comment on Aebi and Neumann. Trends Ecol Evol 27:141–142. https://doi.org/10.1016/j.tree.2011.12.001
Ong PT (2010) Notes on bee pollination in three peninsular Malaysian orchids. Malay Orchid Rev 44:73–75
Ostrowiecka B, Talalaj I, Brzosko E, Jermakowicz E, Mirski P, Kostro-Ambroziak A, Mielczarek L, Lason A, Kupryjanowicz J, Kotowicz J, Wroblewska A (2019) Pollinators and visitors of the generalized food-deceptive orchid Dactylorhiza majalis in North-Eastern Poland. Biologia 74:1247–1257. https://doi.org/10.2478/s11756-019-00285-0
Page ML, Nicholson CC, Brennan RM, Britzman AT, Greer J, Hemberger J, Kahl H, Müller U, Peng Y, Rosenberger NM, Stuligross C, Wang L, Yang LH, Williams NM (2021) A meta-analysis of single visit pollination effectiveness comparing honeybees and other floral visitors. Am J Bot 108:2196–2207. https://doi.org/10.1002/ajb2.1764
Page ML, Williams NM (2022) Honey bee introductions displace native bees and decrease pollination of a native wildflower. Ecology 104:e3939. https://doi.org/10.1002/ecy.3939
Paini DR, Roberts JD (2005) Commercial honey bees (Apis mellifera) reduce the fecundity of an Australian native bee (Hylaeus alcyoneus). Biol Conserv 123:103–112. https://doi.org/10.1016/j.biocon.2004.11.001
Pansarin LM, Pansarin ER, Sazima M (2008) Reproductive biology of Cyrtopodium polyphyllum (Orchidaceae): a Cyrtopodiinae pollinated by deceit. Plant Biol 10:650–659. https://doi.org/10.1111/j.1438-8677.2008.00060.x
Pearn MA (2013) Pollination and comparative reproductive success of lady's slipper orchids Cypripedium candidum, C. parviflorum, and their hybrids in southern Manitoba. Dissertation, University of Manitoba
Pemberton RW, Liu H (2008) Potential of invasive and native solitary specialist bee pollinators to help restore the rare cowhorn orchid (Cyrtopodium punctatum) in Florida. Biol Conserv 141:1758–1764. https://doi.org/10.1016/j.biocon.2008.04.016
Petanidou T, Duffy KJ, Karatza A, Kantsa A (2013) Reduced fecundity in large populations of a Mediterranean orchid - Evidence for pollinator limitation. Basic Appl Ecol 14:36–43. https://doi.org/10.1016/j.baae.2012.11.007
R Core Team (2022) R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. https://www.R-project.org
Rayment T (1932) Two orchids and a bee. Vic Naturalist 49:140–140
Reinhard HR, Gölz P, Peter R, Wildermuth H (1991) Die Orchideen der Schweiz und angrenzender Gebiete. – Fotorotar, Egg 348 pp
Sanguinetti A, Singer RB (2014) Invasive bees promote high reproductive success in Andean orchids. Biol Conserv 175:10–20. https://doi.org/10.1016/j.biocon.2014.04.011
Sasagawa H, Kadowaki T, Matsuyama S (2005) Honeybee communication system and pollination tactics of an oriental orchid that secretes honeybee semiochemicals. Zool Sci 22:1513–1513
Sasaki M, Ono M, Asada S, Yoshida T (1991) Oriential orchid (Cymbidium pumilum) attracts drones of the Japanese honeybee (Apis cerana japonica). as pollinators Experientia 47:1229–1231. https://doi.org/10.1007/BF01918392
Scaccabarozzi D, Cozzolino S, Guzzetti L, Galimberti A, Milne L, Dixon KW, Phillips RD (2018) Masquerading as pea plants: behavioural and morphological evidence for mimicry of multiple models in an Australian orchid. Ann Bot 122:1061–1073. https://doi.org/10.1093/aob/mcy166
Scaccabarozzi D, Guzzetti L, Phillips RD, Milne L, Tommasi N, Cozzolino S, Dixon KW (2020) Ecological factors driving pollination success in an orchid that mimics a range of Fabaceae. Bot J Linn Soc 194:253–269. https://doi.org/10.1093/botlinnean/boaa039
Scaccabarozzi D, Galimberti A, Dixon KW, Cozzolino S (2020) Rotating arrays of orchid flowers: a simple and effective method for studying pollination in food deceptive plants. Diversity 12:286. https://doi.org/10.3390/d12080286
Schiestl FP (2005) On the success of a swindle: pollination by deception in orchids. Sci Nat 92:255–264. https://doi.org/10.1007/s00114-005-0636-y
Schweiger O, Biesmeijer JC, Bommarco R, Hickler T, Hulme PE, Klotz S, Kühn I, Moora M, Nielsen A, Ohlemüller R, Petanidou T, Potts SG, Pyšek P, Stout JC, Sykes MT, Tscheulin T, Vilà M, Walther GR, Westphal C, Winter M, Zobel M, Settele J (2010) Multiple stressors on biotic interactions: how climate change and alien species interact to affect pollination. Biol Rev 85:777–795. https://doi.org/10.1111/j.1469-185X.2010.00125
Schemske DW (1980) Evolution of floral display in the orchid Brassavola nodosa. Evol 489–493. https://doi.org/0.1111/j.1558-5646.1980.tb04838.x
Scopece G, Cozzolino S, Johnson SD, Schiestl FP (2010) Pollination efficiency and the evolution of specialized deceptive pollination systems. Am Nat 175:98–105. https://doi.org/10.1086/648555
Shangguan F, Cheng J, Yuanxin X, Yibo L (2008) Deceptive pollination of an autumn flowering orchid Eria coronaria (Orchidaceae). Biodiv Sci 16:477–483. https://doi.org/10.3724/SP.J.1003.2008.08096
Shrestha M, Dyer AG, Dorin A, Ren ZX, Burd M (2020) Rewardlessness in orchids: how frequent and how rewardless? Plant Biol 22:555–561. https://doi.org/10.1111/plb.13113
Sugahara M (2006) Cymbidium devonianum and Cymbidium suavissimum as well as Cymbidium floribundum attracts Japanese honeybees (Apis cerana japonica). Zool Sci 23:1225
Slater AT, Calder DM (1988) The Pollination Biology of Dendrobium speciosum Smith: a case of false advertising? Aust J Bot 36:145–158. https://doi.org/10.1071/BT9880145
Subedi A, Chaudhary RP, van Achterberg C, Heijerman T, Lens F, van Dooren TJM, Gravendeel B (2011) Pollination and protection against herbivory of Nepalese Coelogyninae (Orchidaceae). Am J Bot 98:1095–1103. https://doi.org/10.3732/ajb.1000306
Suetsugu K (2015) Autonomous self-pollination and insect visitors in partially and fully mycoheterotrophic species of Cymbidium (Orchidaceae). J Plant Res 128:115–125
Suetsugu K, Abe Y (2021) Unexpected contribution of the introduced honeybee Apis mellifera to high fruit set in Spiranthes australis (Orchidaceae). Entomol News 129:559–563. https://doi.org/10.3157/021.129.0511
Suetsugu K, Fukushima S (2014) Bee pollination of the endangered orchid Calanthe discolor through a generalized food-deceptive system. Plant Syst Evol 300:453–459. https://doi.org/10.1007/s00606-013-0894-7
Sugahara M, Izutsu K, Nishimura Y, Sakamoto F (2013) Oriental Orchid (Cymbidium floribundum) Attracts the Japanese Honeybee (Apis cerana japonica) with a Mixture of 3-hydroxyoctanoic Acid and 10-hydroxy-(E)-2-decenoic Acid. Zool Sci 30:99–104. https://doi.org/10.2108/zsj.30.99
Sugahara M, Minamoto T, Fuchikawa T, Michinomae M, Shimizu I (2010) Apis cerana japonica Discriminates between Floral Color Phases of the Oriental Orchid, Cymbidium floribundum. Zool Sci 27:901–906. https://doi.org/10.2108/zsj.27.901
Sugiura N (1995) The pollination ecology of Bletilla striata (Orchidaceae). Ecol Res 10:171–177. https://doi.org/10.1007/BF02347939
Sugiura N (2014) Pollination and floral ecology of Arundina graminifolia (Orchidaceae) at the northern border of the species’ natural distribution. J Plant Res 127:131–139. https://doi.org/10.1007/s10265-013-0587-x
Sun HQ, Luo YB, Ge S (2003) A preliminary study on pollination biology of an endangered orchid, Changnienia amoena, in Shennongjia. J Integr Plant Biol 45:1019–1023. https://www.jipb.net/EN/Y2003/V45/I9/1019
Tao ZB, Ren ZX, Bernhardt P, Liang H, Li HD, Zhao YH, Wang H, Li DZ (2018) Does reproductive isolation reflect the segregation of color forms in Spiranthes sinensis (Pers.) Ames complex (Orchidaceae) in the Chinese Himalayas? Ecol Evol 8:5455–5469. https://doi.org/10.1002/ece3.4067
Thomson D (2004) Competitive interactions between the invasive European honeybee and native bumble bees. Ecol 85:458–470. https://doi.org/10.1890/02-0626
Thomson DM, Page ML (2020) The importance of competition between insect pollinators in the Anthropocene. Curr Opin Insect Sci 38:55–62. https://doi.org/10.1016/j.cois.2019.11.001
Traveset A, Richardson DM (2014) Mutualistic interactions and biological invasions. Ann Rev Ecol Evol Syst 45:89–113. https://doi.org/10.1146/annurev-ecolsys-120213-091857
Tremblay RL, Ackerman JD, Zimmerman JK, Calvo RN (2005) Variation in sexual reproduction in orchids and its evolutionary consequences: a spasmodic journey to diversification. Biol J Linn Soc 84:1–54. https://doi.org/10.1515/biorc-2015-0024
Tsuji K, Kato M (2010) Odor-guided bee pollinators of two endangered winter/early spring blooming orchids, Cymbidium kanran and Cymbidium goeringii, in Japan. Plant Species Biol 25:249–253. https://doi.org/10.1111/j.1442-1984.2010.00294.x
Venables WN, Ripley BD (2022) Modern Applied Statistics with S, 4th edn. Springer, New York
Valido A, Rodríguez-Rodríguez MC, Jordano P (2019) Honeybees disrupt the structure and functionality of plant-pollinator networks. Sci Rep 9:1–11. https://doi.org/10.1038/s41598-019-41271-5
Van der Pijl L, Dodson H (1966) Orchid flowers: Their pollination and evolution, 1st edn. The Fairchild Tropical Garden and the University of Miami Press, Coral Gables
Verma J, Thakur K, Sembi JK, Attri LK, Kant R, Vij SP (2012) Pollination in Cymbidium pendulum. (Roxb) Sw (Orchidaceae) Vegetos 25:298–302
Vöth W (1987) Bestäubungsbiologische Beobachtungen an Orchis militaris L. Die. Orchidee 38:77–84
Vöth W (1998) Orchis italica und die angetroffenen Insekten. Die Orchidee 49:219–221
Vöth W (1989) Werden Ophrys aesculapii RENZ von Andrena muscaria WARNCKE. (Andrenidae) bestäubt? Mitt Bl Arbeitskr Heim Orch Baden-Württ 21:133–142
Vöth W (1994) Bestäuber und Besucher der Blüten von Traunsteinera globosa (L.) Rchb., Orchidaceae, in Niederösterreich. – Linzer Biologische Beitraege 26:133–148
Vöth W (1999) Lebensgeschichte und Bestäuber der Orchideen am Beispiel von Niederösterreich. Stapfia 65 Biologiezentrum. Oberösterreichisches Landesmuseum, Linz
Wilckman H (2011) The split-apply-combine strategy for data analysis. J Stat Softw 40:1–29. https://www.jstatsoft.org/article/view/v040i01
Wickham H (2016) ggplot2: elegant graphics for data analysis. Springer-Verlag, New York. ISBN 978-3-319-24277-4
Wilcove DS, Rothstein D, Dubow J, Phillips A, Losos E (1998) Quantifying threats to imperiled species in the United States. Bioscience 48:607–615. https://doi.org/10.2307/1313420
Wroblewska A, Szczepaniak L, Bajguz A, Jedrzejczyk I, Talalaj I, Ostrowiecka B, Brzosko E, Jermakowicz E, Mirski P (2019) Deceptive strategy in Dactylorhiza orchids: multidirectional evolution of floral chemistry. Ann Bot 123:1005–1016. https://doi.org/10.1093/aob/mcz003
Yu XH, Luo YB, Dong M (2008) Pollination biology of Cymbidium goeringii (Orchidaceae) in China. J Syst Evol 46:163–174. https://doi.org/10.3724/SP.J.1002.2008.06203
Zha ZB, Tang J, Liang YL, Ding H, Luo HL, Yang BY (2016) Breeding system and pollination biology of Goodyera foliosa (Orchidaceae). Trop Subtrop Bot 24:333–341
Zhou X, Lin H, Fan XL, Gao JY (2012) Autonomous self-pollination and insect visitation in a saprophytic orchid, Epipogium roseum (D. Don) Lindl. Aust J Bot 60:154–159. https://doi.org/10.1071/BT11265

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Introduced honeybees (Apis mellifera) in orchid pollination: surrogate pollinators or pollen wasters?

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Abstract

Figures

Introduction

Materials and methods

2.1 Literature survey: incidence of honeybees in pollination of orchids

2.2 Study species

2.3 Study sites

2.4 Orchid pollination success

2.5 Observational transects on pollinator occurrence

2.6 Statistical analysis

Results

3.1 Incidence of honeybees in pollination of orchids

3.2 Orchid pollination in relation to occurrence of native and alien honeybees

3.3 Effect of habitat type and size on pollination success and efficiency

Discussion

4.1 Introduced honeybees likely impacting orchid pollination globally

4.2 Orchid pollination success and efficiency in relation to occurrence of native and alien honeybees

4.3 Effect of habitat type and size on pollination success and efficiency

Conclusion

Declarations

References

Supplementary Files

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