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Wild pollinators of eastern apple orchards and how to conserve them

Authors:

Abstract

Pollinators are declining worldwide, as are their pollination services9. Eastern orchards have a unique opportunity to simultaneously conserve wild bee populations and to benefit from their contribution to fruit pollination. The mixed eastern landscape, comprised of orchard blocks interspersed with woodlots, fallow fields and hedgerows, provides bees with needed natural habitat in close proximity to orchards. Simply protecting bee resources that already exist on grower lands is an important first step in ensuring wild bee pollination. By encouraging wild bee abundance and diversity, agricultural growers may be able to buffer rising honey bee rental costs (a win for farmers), while creating an environment that better supports both wild and commercial bees (a win for all bees).
1
WILD POLLINATORS of
EASTERN APPLE ORCHARDS
and how to conserve them
INTRODUCTION







WHY CONSIDER WILD BEES AS POLLINATORS NOW?
Honey bees are the most widely used insect pollinator in agricultural systems, as they
are easily managed. However, due to disease and compeng demands, the cost of
hive rentals connues to increase as supplies decrease. Farmers are aware of these
challenges as evidenced by a 2009 mail survey where 65% of New York apple growers
indicated that Colony Collapse Disorder of honey bees would negavely aect apple
producon3. For the same reason that diversied invesng is safer than dependence on
a single stock, relying on a single pollinator for this vital service may pose increasing risk.
Honey bees will no doubt remain a key pollinator for agricultural systems, but research
suggests more and more that wild bees are contribung to apple pollinaon.
WHAT ARE WILD BEES AND HOW DO THEY BENEFIT ME?
Besides honey bees, about 450 other bee species live in the eastern United States.
Over  of these wild bees visit apple orchards. Most of these bees are nave to the
region, while at least one (the Hornfaced Bee, Osmia cornifrons) was introduced for
fruit pollinaon. Mail surveys of New York and Pennsylvania apple growers reveal that,
when abundant, wild bees provide all the pollinaon an orchard needs…and they do so
for FREE3,4! Further, careful pollinaon studies have shown that wild bees can be more
eecve pollinators than honey bees on a per-visit basis5,6,7, meaning they do not need
to be as abundant as honey bees to provide the same level of pollinaon. Wild bees
are a valuable orchard asset whose contribuons are only now beginning to be fully
appreciated.
WHY SHOULD I CARE ABOUT DIVERSITY?
Bee diversity stabilizes pollinaon services through me8. The more species in an area,
the more likely there will be a species that can tolerate variable climac condions, like
a cold and wet spring. Similarly when bee diversity is high, even if there is one species
that is exrpated by disease, parasites, pescides or habitat loss, other species connue
to thrive and pollinate.
FRONT COVER: Featured Bees
Common Eastern Bumble Bee,
Bombus imp atiens
Blue-Green Sweat Bee, Augochlora pura
Small Mining Bee, Andrena nasonii
Large Mining Bee, Andrena regularis
Hornfaced Bee, Osmia cornifrons
CITATION:
et al.

AUTHORS:



ACKNOWLEDGEMENTS:







This publicaon is supported, in part, with funding from the
Northeastern IPM Center (NortheastIPM.org) and the USDA Naonal
Instute of Food and Agriculture.
Mission of the Center: The Northeastern Integrated Pest Management Center fosters the
development and adopon of IPM, a science-based approach to managing pests in ways that
generate economic, environmental, and human health benets. The Center works in partnership
with stakeholders from agricultural, urban, and rural sengs to idenfy and address regional
priories for research, educaon, and outreach.
3



bee species are solitary, and








pollen and nectar, and then lay

then sealed in the chamber and





the nest and restart the cycle.
INTRODUCTION
WIN-WIN FOR WILD BEES AND GROWERS?
Pollinators are declining worldwide, as are their pollinaon services9. Eastern orchards
have a unique opportunity to simultaneously conserve wild bee populaons and to
benet from their contribuon to fruit pollinaon. The mixed eastern landscape,
comprised of orchard blocks interspersed with woodlots, fallow elds and hedgerows,
provides bees with needed natural habitat in close proximity to orchards. Simply
protecng bee resources that already exist on grower lands is an important rst step
in ensuring wild bee pollinaon. By encouraging wild bee abundance and diversity,
agricultural growers may be able to buer rising honey bee rental costs (a win for
farmers), while creang an environment that beer supports both wild and commercial
bees (a win for all bees).
IN THIS BOOKLET YOU WILL FIND…
 

 

 

4. 

 
BEE FACTS











on nectar and pollen.











4 5
6


7mm 

THE MOST COMMON BEES IN YOUR ORCHARD
GROUND-NESTERS
The most important wild pollinators of apple are ground-nesng bees. Ground-nesters
excavate underground nests, comprised of tunnels and egg chambers where the young
develop – a nesng strategy shared by 70% of bees worldwide. To avoid moisture-loving
microbes that aack food and young, nests are built in well-drained soils. These nests
are dicult to nd because the entrance is normally a simple hole in the ground, just
big enough for the bee to move in and out.
Well-drained soil with access to bare ground.
 Tilling, mulching, toxic herbicides like Paraquat (trade name
Gramoxone), and compacon.
Protect nesng sites from above threats and improve access to
bare soil; provide oral resources through the growing season.
KEY
LARGE MINING BEES (Andrena spp.)



CELLOPHANE BEES
(Colletes inaequalis)



Augochlora pura,




SMALL MINING BEES (Andrena spp.)
DARK SWEAT BEES
(Lasioglossum spp., Halictus spp.)
BLUE-GREEN SWEAT BEES
(Augochlora pura, Agapostemon spp.,
Augochlorell a aurata)
FORAGING: SOCIALITY: FLIGHT RANGE:
 Specialist Solitary Social   



7
8
THE MOST COMMON BEES IN YOUR ORCHARD
CAVITY-NESTERS
This bee group is most familiar to us and includes honey bees and bumble bees. Such
bees do not excavate their own nest, but nd exisng cavies to house their social
colonies and honey supplies. Because these bees are acve all summer long, they
require constant (or at least long term) oral resources in the vicinity of the hive.
Cavies in trees, in wooden structures or below-ground.
 Habitat loss (i.e., inadequate nesng and food sites), pescide dri.
 Protect or enhance adjacent, woody natural areas; provide oral
resources through the growing season; establish 20- buer for dri.
TUNNEL-NESTERS
As their name implies, these bees either excavate tunnels in wood (e.g., carpenter bees)
or use abandoned cavies, such as beetle burrows, or even cracks in masonry (e.g., mason
bees). Among the most important nave (and somemes managed) pollinators are mason
bees (genus Osmia). Mason bees are eecve apple pollinators and populaons can be
increased through the use of arcial nesng materials. For more informaon on mason
bee biology and management, see Bosch & Kemp 2001 (listed below under secon entled
“MORE POLLINATOR CONSERVATION RESOURCES”).
 Stems, trees, rong logs, wooden structures or old masonry.
Habitat loss (i.e., not enough nesng sites) and pescide dri.
Protect or enhance adjacent, woody natural areas and old stone
walls; provide nesng materials; maintain oral resources through the growing
season; establish a 20- buer for dri.

KEY
FORAGING: SOCIALITY: FLIGHT RANGE:
 Specialist Solitary Social   
BUMBLE BEES (Bombus spp.)


produced later once the colony is established. In contrast,
commercial colonies are raised indoors and contain both



LARGE CARPENTER BEES
(Xylocopa virginica)




West, the blue orchard bee, Osmia lignaria

bee, O. cornifrons
HONEY BEES (Apis mellifera)
SMALL CARPENTER BEES (Ceratina spp.)
MASON BEES (Osmia spp.)




11
CONSERVATION
IN ORDER FOR WILD BEES TO THRIVE,
THREE BASIC NEEDS MUST BE MET:
 
 
 
You may already take great care to provide these needs for honey bees, but wild bees
are unique in that they cannot be taken in and out of the orchard at will, so they must
be considered beyond the short bloom period. Moreover, wild bees are more vulnerable
because, unlike honey bees that send workers to forage, wild bee foragers are the
reproducing individuals for that populaon.
PROTECT AND ENHANCE POLLINATOR FOOD SOURCES
Wild bees require a connuous and diverse source of pollen and nectar to sustain
themselves and their young. Because they live longer than the short apple bloom, it is
crical that other oral resources are available within ight distance from your orchard.

protect oral resources already available on your land:
 
 
 
 
 
 increase oral resources on your property to
build pollinator populaons. Floral planngs come in various
forms:
 
 
 
USDA Plant Materials Centers, Xerces Society and university
researchers are developing region-specic plant mixes for
pollinators; funding is available for such planngs on farms
(discussed below). Flip to pages 14 and 15 for a guide to
plants that benet orchard pollinators.
GOVERNMENT COST-SHARE PROGRAMS
USDA’s Farm Service Agency (FSA) and Natural Resources Conservaon Service (NRCS)
provide funding opportunies for individual farmers to defray the costs of improving
lands for pollinators:
1. Conservaon Reserve Program (CRP) is a land rerement program that aims to
enhance wildlife habitat.
Website: 
rp. Contact your local USDA FSA service center to apply.
2. Environmental Quality Iniaves Program (EQIP) supports conservaon
pracces that improve environmental quality of land.
Website:
See website for state-specic applicaon instrucons.
3. Wildlife Habitat Incenves Program (WHIP) funds establishment and
improvement of wildlife habitat.
Website: 
Contact your local USDA NRCS service center to apply.
BEE & BLOOM PHENOLOGY*
BLOOM GROUND NESTERS CAVITY NESTERS TUNNEL NESTERS
Apple
Plum
Peach
Cherry
Large mining Bees
Small Mining Bees
Cellophane Bees
Dark Sweat Bees
Blue-Green Sweat Bees
Bumble Bees
Large Carpenter Bees
Small Carpenter Bees
Mason Bees
March April May June July August Septeber October November December
Pollinator planting jointly
established by the Xerces Society,
USDA NRCS, and the University of
New Hampshire Extension.
* Timing is generalized for the eastern U.S. and will vary according to your latitude and microclimate.
10
 
 



In general, be mindful that wild bees are present on farms before and aer the apple
bloom and may even be nesng within tree rows. On pages 16 and 17, you will nd a
table that ranks bee toxicity of pescides most commonly used in orchards.
MORE POLLINATOR CONSERVATION RESOURCES…

The Xerces Society, , provides a wealth of informaon on pollinator
conservaon, including downloadable factsheets and publicaons, as well as links to
other sources.
Pollinator Partnership, , is a non-prot coalion dedicated to the
conservaon of North American pollinators. Check out their resources for farming.
Penn State University’s Center for Pollinator Research,,
conducts research and outreach for wild and managed pollinators. Latest news on CCD
and outreach informaon are found here.
Cornell University’s Wild Pollinator Program, ,
serves as a portal to research and outreach about non-honey bee pollinators of New
York crops and nave plants.

Bosch, J. and W. Kemp. 2001. How to Manage the Blue Orchard Bee as an Orchard
Pollinator. The Naonal Outreach Arm of USDA-SARE, Handbook Series, Book 5.
Sustainable Agriculture Network, Naonal Agricultural Library, Beltsville, MD. 

Mader, E., M. Shepherd, M. Vaughan, S.H. Black and G. LeBuhn. 2011. Aracng Nave
Pollinators. Storey Press.
Mader, E., M. Spivak and E. Evans. 2010. Managing Alternave Pollinators: A Handbook
for Beekeepers, Growers, and Conservaonists, SARE Handbook 11, copublished by
SARE and NRAES. 
Reidl, H., E. Johansen, L. Brewer and J. Barbour. 2006. How to Reduce Bee Poisoning
from Pescides. Oregon State University. 

USDA NRCS. 2009. New England Biology Technical Note: Pollinator Biology and Habitat.


Vaughan, M., M. Shepherd, C. Kremen, and S.H. Black. 2007. Farming for Bees:
Guidelines for Providing Nave Bee Habitat on Farms. 2nd ed. 

PROVIDE SAFE NESTING SITES
The best way to provide safe nesng is to maximize undisturbed areas around your
farm. Ground nesters benet most if areas with semi-barrren, sandy soils are protected
from compacon or lling. Both tunnel- and cavity-nesters nest in or at the edge of
woody semi-natural or natural areas, as well as in old stone walls and sheds.
HOW TO CREATE NEW NESTING SITES

 Shallow ll well-drained areas once and maintain
bare ground with glyphosate.
 Pile old trees that are pulled near orchard.
Place self-made or purchased stem nests made
from tubes or drilled wood close to orchard but
safe from pescide dri. Start small to see if
tunnel-nesters are in your area. See Mader et al.
201010 for further informaon.
 Pile old trees that are pulled near orchard.
Do not destroy rodent holes
PROTECT BEES FROM PESTICIDES
Pescides, including fungicides and even some herbicides, are a general danger to bees,
but wild bees are more impacted because they reproduce more slowly than honey bees
and each wild bee is not only a worker but also a reproducer. Here are some general
guidelines to protect bees from pescides:
 
 

Cellophane bee at the
entrance of her ground nest.
Block nest for mason bees by
a pear tree.
Bumble bee nest in a pile of
old leaves and grass.
CONSERVATION
12 13
FORAGE PLANTS FOR WILD POLLINATORS
COMMON NAME SPECIES NAME FORM

Amelanchier spp.
tree


Salix discolor



Lupinus perennis



Tilia americana
tree


Coreopsis lanceolata


Smooth penstemon
Penstemon digitalis



Asclepias spp.


Flowering SeASon: SPRING SUMMER
Both wild and commercial bees would benet from increased oral resources on your land.
Choose combinaons of plants, so that dierent ower types are available throughout the enre
growing season. The species recommended below are all eastern nave perennials.

Echinacea spp.



Monarda stulosa



Eupatorium purpureum

mesic, 

Agastache foeniculum



Helianthus giganteus



Spiraea alba
shrub


Symphyotrichum novae-angliae


SUMMER FALL
1514
TOXICITY OF PESTICIDES TO BEES
(NOTE: TOXICITY RATINGS BASED ON HONEY BEE TESTS)
Disclaimer: These data mostly incorporate studies looking at acute, short-term adult toxicity.
The eects on other life stages from feeding on contaminated pollen might be dierent in
chronic exposure. For example, larvae exposed to some IGRs could have developmental and
reproducve eects including reducons in fecundity and ferlity. Also, eects on non-honey
bee, pollinang insects are not well known.
Note: On-going research has recently shown that even the inert ingredients that are part of the pescide formulaon can be toxic to
honey bees by impairing their ability to learn. Of the inert ingredients tested, organosilicone surfactants/adjuvants were most toxic.
Other non-ionic surfactants showed some toxicity and crop oils were least toxic.
CHEMICAL CLASS/GROUP EXAMPLES OF COMMON NAMES EXAMPLES OF TRADE NAMES NON LOW MODERATE HIGH
  
 
  
 
  
dimethoate, malathion, methidathion, phosmet 
  
  
 
 
  
 
 
  
  
spinetoram, spinosad 
  
 
 
 
 
  
 
 
 
Bacillus thuringiensis, Cydia pomonella 
  
 

  
TOXICITY LEVEL
17
NOTES
CITED REFERENCES
1 Morse, R. A. & Calderone, N. W. The value of honey bees as pollinators of U.S. crops in 2000. Bee
Culture, 1-15 (2000).
2 Losey, J. E. & Vaughan, M. The economic value of ecological services provided by insects. Bioscience
56, 311-323 (2006).
3 Park, M., Orr, M. & Danforth, B. in New York Fruit Quarterly Vol. 18 21-25 (New York State
Horcultural Society, Geneva, NY, 2010).
4 Joshi, N. K., Biddinger, D. & Rajoe, E. G. in 10th Internaonal Pollinaon Symposium (Puebla,
Mexico, 2011).
5 Bosch, J. & Kemp, K. How to Manage the Blue Orchard Bee, as an Orchard Pollinator. (Sustainable
Agriculture Network, 2001).
6 Winfree, R., Williams, N. M., Dusho, J. & Kremen, C. Nave bees provide insurance against ongoing
honey bee losses. Ecology Leers 10, 1105-1113 (2007).
7 Thomson, J. D. & Goodell, K. Pollen removal and deposion by honeybee and bumblebee visitors to
apple and almond owers. Journal of Applied Ecology 38, 1032-1044 (2001).
8 Winfree, R. & Kremen, C. Are ecosystem services stabilized by dierences among species? A test using
crop pollinaon. Proceedings of the Royal Society B 276, 229-237 (2009).
9 Pos, S. G. et al. Global pollinator declines: trends, impacts and drivers. Trends in Ecology and
Evoluon 25, 345-353 (2010).
10 Mader, E., Spivak, M. & Evans, E. in SARE Handbook 11 (copublished by SARE and NRAES, 2010).
PHOTO CREDITS
Aside from those taken from public domain, photos were used with permission from the following
individuals, who maintain copyright privileges.
Page:
4: Milkweed, Asclepias syriaca, Albert F. W. Vick, Lady Bird Johnson Wildower Center.
5: Bee life cycle, Dennis Briggs and Robbin Thorp (pupa), UC Davis; boom le, Colletes inaequalis,
John Ascher, www.discoverlife.org; boom right, Andrena spp., Kent Loeer, Cornell
University.
6: Large and small mining bees, Andrena spp., Kent Loeer, Cornell University.
7: Cellophane bee, Colletes inaequalis, Alberto Lopez; dark sweat bee, Lasioglossum spp. and
Halictus spp., Kent Loeer, Cornell University; blue-green sweat bee, Augochlora pura, Tom
Murray, www.pBase.org.
8: Bumble bee, Bombus impaens, Tom Murray, www.pBase.org; honey bee, Apis mellifera, Kent
Loeer, Cornell University.
9: Large carpenter bee, Xylocopa virginica, Kent Loeer, Cornell University; small carpenter bee,
Cerana dupla, JelleDevalez, www.discoverlife.org; mason bee, Osmia cornifrons, USDA ARS.
10: Bumble bee on Monarda stulosa, Eric Mader, The Xerces Society.
11: Pollinator planng, Don Keirstead (USDA-NRCS).
12: Le, cellophane bee nest, Margarita Lopez-Uribe; center, block nest, Mahew Shepherd, The
Xerces Society; right, bumble bee nest, Al Eggenberger.
14: Service berry, Amelanchier spp., David G. Smith, www.delawarewildowers.org; Pussy willow,
Salix discolor, Albert F. W. Vick, Lady Bird Johnson Wildower Center; Lupine, Lupinus
perennis, W. D. Bransford, Lady Bird Johnson Wildower Center; Basswood, Tilia Americana,
Toby Alexander/USDA-NRCS; Lance-leaf coreopsis, Coreopsis lanceolata, David Cappaert,
Michigan State University, Bugwood.org; Smooth penstemon, Penstemon digitalis, David G.
Smith, www.delawarewildowers.org; Milkweed, Asclepias syriaca, Albert F. W. Vick, Lady
Bird Johnson Wildower Center.
15: Purple coneower, Echinacea purpurea, Joseph A. Marcus, Lady Bird Johnson Wildower Center;
Wild bergamot, Monarda stulosa, Catherine Herms, The Ohio State University, Bugwood.
org; Joe Pye weed, Eupatorium purpureum, Mahew Shepherd, The Xerces Society;
Blue giant hyssop, Agastache foeniculum, Andy and Sally Wasowski, Lady Bird Johnson
Wildower Center; White meadowsweet, Spiraea alba sub. lafolia, J.S. Peterson, USDA-
NRCS PLANTS Database; New England aster, Symphyotrichum novae-angliae, Pennsylvania
Department of Conservaon and Natural Resources, Forestry Archive, Bugwood.org.
18

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... The values to each indicator were assigned based on a bibliographic review on case studies of the EAMIS framework, sustainable agriculture manuals (CA, IPM, and OA), apple production manuals, regional and national statistical yearbooks, among other sources. (Sarandón, 2002;Sarandón and Flores, 2009;Sarandón et al., 2019;Masera et al., 2000;Dellepiane and Sarandón, 2008;Granatstein and Peck, 2017;Wang et al., 2016;Kellerhals, 2009;Brown, 2012;Zhang et al., 2011;Biddinger et al., 2018;Park et al., 2012;Sheffield et al., 2016;INEGI, 2009a,b,c; Government of the Puebla State, 2014a;b; Abbona et al., 2007;Meza & Julca-Otiano, 2015;Valdivia-Espinoza et al., 2020;Valarezo-Beltrón et al., 2020;Scoponi, 2016;Scoponi et al., 2019). According to these sources, optimal practices for apple cultivation were consulted, as well as other evaluations performed under the EAMIS framework, so that a gradient of options could be generated for each indicator (Supplementary Tables 1-2; Supplementary material). ...
... It must be reiterated the importance of native bees as potential pollinators of apple trees considering the trend that producers have identified regarding the growth of asymmetric apples in years in which the presence of bees decreases. According to Park et al. (2012), the most observed wild bee species for the pollination of apple crops are the mining bees, such as Andrena sp., Lasioglossum sp. and Agapostemon sp.; because they tend to nest in well-drained soils that are the most appropriate for growing apples. Other common species in these orchards are cavity nesting bees (Bombus spp.) and mason bees (Ceratina spp., Osmia spp.) (Supplementary Table 6; Supplementary materials) (Martins et al., 2015;Sheffield et al., 2016;Park et al., 2012). ...
... According to Park et al. (2012), the most observed wild bee species for the pollination of apple crops are the mining bees, such as Andrena sp., Lasioglossum sp. and Agapostemon sp.; because they tend to nest in well-drained soils that are the most appropriate for growing apples. Other common species in these orchards are cavity nesting bees (Bombus spp.) and mason bees (Ceratina spp., Osmia spp.) (Supplementary Table 6; Supplementary materials) (Martins et al., 2015;Sheffield et al., 2016;Park et al., 2012). All of them found in at least one of the studied orchards in this study. ...
... Similar to our investigation Kaundal et al., 2022 [10] , Kaundal and Thakur, 2020 [9] ; Raj et al. (2012 [18] also found Hymenopterans and Dipterans as the most predominant insect species on apple blossom. Park et al. (2012) [15] also noted a remarkable diversity of native bee species in the orchards, adding that native bees were particularly abundant in the apple orchards. Pollinators diversity showed no significant difference between species captured by sweep net methods. ...
Experiment Findings
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A study was conducted to investigate the diversity and quantity of insect pollinators in the apple orchards of Seraj valley, HP. The current study comprised 56 insect pollinator species from 25 families, grouped into eight orders: Hymenoptera, Diptera, Lepidoptera, Coleopteran, Hemiptera, Neuroptera, Thysanoptera, and Orthoptera. Overall, the study region had the highest abundance of 1127 individuals (Apis cerana, Apis mellifera, and Ceratina sp.), accounting for 76% of the family contribution. The most prevalent orders were Hymenoptera, Diptera, and Lepidoptera, with 18, 17, and 11 species, respectively, whereas Hemiptera, Thysanoptera, and Neuroptera had only one species in each. Pollinator diversity did not differ significantly amongst species caught using sweep net methods. Muscidae has the highest pollinator diversity (0.59/5 sweeps), followed by Halictidae (0.52/5 sweeps), Syrphidae (0.51/5 sweeps), and Bibionidae (0.30/5 sweeps). The family apidae (Apis mellifera and Apis cerana) was found to be the most prominent in apple orchards (4.08/100 flowers), followed by the families syrphidae (3.41/100 flowers), halictidae (1.70), and tephritidae (1.51/100 flowers). Insect visitors sampled using several sampling methods demonstrated that for sampling pollinator diversity, all methods must be used together because no single method is completely reliable.
... Similar to our investigation Kaundal et al., 2022 [10] , Kaundal and Thakur, 2020 [9] ; Raj et al. (2012 [18] also found Hymenopterans and Dipterans as the most predominant insect species on apple blossom. Park et al. (2012) [15] also noted a remarkable diversity of native bee species in the orchards, adding that native bees were particularly abundant in the apple orchards. Pollinators diversity showed no significant difference between species captured by sweep net methods. ...
... Notwithstanding the benefits of actively restoring land to enhance biodiversity, conserving bee habitat that already exists near crops is perhaps the first step towards safeguarding native bee pollination (Park et al. 2012), and this supports both pollination and biodiversity conservation generally in fragmented landscapes. Considerate management of these remnant patches by land managers or community natural resource management groups can benefit orchardists by increasing the resilience of pollination services and enhancing crop yield and quality. ...
Article
Maintenance of a diverse pollinator community helps ensure resilience in pollination services. Fragments of woody and grassy vegetation in the vicinity of croplands have been shown to encourage the presence of crop‐pollinating bees. However, to date, little attention has been given to the management practices that may enhance the presence of bees in such fragments. We investigated how the maintenance of remnant forest fragments adjacent to apple orchards in South Australia affects floral resources and native bee communities. The fragments had been subject to either (a) fire (assessments three years post‐burn), (b) cattle grazing under trees and (c) low maintenance management (>20 years not grazed or burnt). Plant communities were sampled along transects in plots. Bee communities were sampled using hand netting. We fitted generalised linear mixed models to investigate differences in plant and bee diversity between treatments and to elucidate the effect of plant diversity on bee diversity. We compared plant and bee community composition among treatments using non‐metric multidimensional scaling and conducted network analysis to measure the robustness of plant‐pollinator interactions to the removal of species. Both floral resource abundance and bee diversity were higher in burnt and low‐maintenance fragments than in grazed fragments. Bee species richness was positively associated with plant species richness. The species richness of bees that visit apple flowers was positively associated with flower abundance but not with floral species richness. Plant‐pollinator networks in grazed sites had fewer links per species and a higher proportion of realised links than those under other management practices. However, the resilience of pollinator networks did not differ significantly between management practices. Thus, controlled burns or low‐maintenance management of forest fragments appear to be the most suitable landscape management practices to support apple pollinating bees. Burning requires consideration of additional ecological consequences, such as the conservation of fire‐sensitive species and specialist woodland fauna. Cattle grazing adjacent to orchards results in simplified bee communities and pollination networks and is not recommended if pollination services are required for adjacent land uses. This information can benefit orchardist as well as managers of fragments of native vegetation adjacent to orchard crops.
... Floral resources for pollinators in perennial crops such as apples are preferably provided in mixtures of plant species of several families such as Apiaceae, Fabaceae, Brassicaceae, etc. [60,62,90]. In this kind of mixtures, the inclusion of traditional varieties would offer a dual benefit since they are part of each country's cultural heritage, which should be well conserved [91], and their exploitation in agricultural practices would offer an extra incentive to the producer to preserve them on farm. ...
Article
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Apples depend on insect pollination but intensification of agriculture jeopardizes pollination services in agroecosystems. Concerns about the dependency of crop pollination exclusively on honey bees increase the interest in agricultural practices that safeguard wild pollinators in agroecosystems. The purpose of the study was to assess the potential of floral resource provision in apple orchards to enhance the conservation of hymenopterous pollinating insects and potentially the pollination service to the crop. For this reason, flowering plant mixtures sown in patches inside apple orchards were tested against wild plant patches. Pollinator taxa recorded on the sown and wild plant patches were honey bees, wild bees (Andrena, Anthophora, Eucera, Halictus, Lasioglossum, Megachilidae on both; Systropha only on wild plants; Bombus, Hylaeus, Sphecodes, Nomada, Xylocopa only on sown mixture), syrphids, bee flies. The most abundant pollinator of apple was A. mellifera but wild bees were also recorded (Andrena, Anthophora, Bombus, Xylocopa, Lasioglossum, Megachilidae). The sown mixture attracted a more diverse taxa of pollinators and in greater numbers compared to the weed flora, but it did not have an effect on pollinators visiting apple flowers. Groundcover management with patches of suitable flowering mixtures can enhance pollinator conservation in apple orchards.
... Honeybees visit crop flower more reflects these species are the main insect pollinators of agricultural landscape. As [30] reported honeybees are the most widely used insect pollinator in agricultural systems, as they are easily managed. Honeybees and other insect pollinators have significant effect on Niger seed yield, so that keep their colonies neighboring to flowers of Niger seed in order to optimize pollination efficiency and enhance productivity [31]. ...
... Rubus spp. and C. canadaensis for O. cornifrons in orchards; [22,23,51,52]). ...
Article
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Studying the pollen preferences of introduced bees allows us to investigate how species use host-plants when establishing in new environments. Osmia cornifrons is a solitary bee introduced into North America from East Asia for pollination of Rosaceae crops such as apples and cherries. We investigated whether O. cornifrons (i) more frequently collected pollen from host-plant species they coevolved with from their geographic origin, or (ii) prefer host-plant species of specific plant taxa independent of origin. To address this question, using pollen metabarcoding, we examined the identity and relative abundance of pollen in larval provisions from nests located in different landscapes with varying abundance of East-Asian and non-Asian plant species. Our results show that O. cornifrons collected more pollen from plant species from their native range. Plants in the family Rosaceae were their most preferred pollen hosts, but they differentially collected species native to East Asia, Europe, or North America depending on the landscape. Our results suggest that while O. cornifrons frequently collect pollen of East-Asian origin, the collection of pollen from novel species within their phylogenetic familial affinities is common and can facilitate pollinator establishment. This phylogenetic preference highlights the effectiveness of O. cornifrons as crop pollinators of a variety of Rosaceae crops from different geographic origins. Our results imply that globalization of non-native plant species may ease the naturalization of their coevolved pollinators outside of their native range.
Article
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Pollinators play important roles in providing pollination services, maintaining biodiversity, and boosting crop production. Even though pollinators are essential to the environment and agriculture, their decline has been noted across multiple studies in the recent past. Both natural and anthropogenic factors have contributed to their decline. Much of the focus has been placed on climate change, habitat loss, pests and pathogens, and synthetic pesticides, but relatively little is known about the effects of biopesticides. Biopesticides are biological control agents derived from living organisms and are classified into three groups: microbial, biochemical, and plant-incorporated protectant-based products. Biopesticides are formulated similarly to their synthetic counterparts and are readily available and used within urban and agricultural settings by pest management experts and household residents. The general public and much scientific literature support the prevailing idea that biopesticides are environmentally safe and pollinator friendly in comparison with synthetic versions. However, such generalizations are based on studies with a few key pollinator species and may not be relevant to several other species that provide crop pollination services. Studies focused on native pollinators have shown that some biopesticides have lethal and sublethal effects. Because each biopesticide exhibits varying effects across pollinator species, it could be dangerous to generalize their non-toxicity across taxa and environmental settings. In this article, recent research in this direction is discussed.
Article
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Insect dependency of apple crop for pollination vary in different cultivars. The cv. ‘Delicious Pilafa Tripoleos’, is a Protected Designation of Origin apple of Greece, which lacks information on self-compatibility and needs for insect pollination for commercial fruit production. Here, the effect of wind, free (wind and insects), honeybee, free with at least one visit from a bumblebee and hand pollination was examined on fruit set and fruit characteristics. Also, the effect of flowering patches as a practice to attract pollinators in the apple orchards, on fruit quality characteristics was studied. A pollinizer apple variety and insect pollinators are necessary for successful pollination of ‘Delicious Pilafa Tripoleos’ since hand pollination with pollen of the same cv., and wind pollination resulted in very low fruit set. Single flower visits by honeybees could give fruit set, however, free pollination with at least one visit of B. terrestris resulted in higher fruit set compared to the other pollination treatments. Free pollination resulted in more fruits with higher number of seeds than wind pollination (only one fruit obtained). Apples produced from flowers adjacent to the flowering mixture patches had significantly higher skin firmness and lower total soluble solids at harvest (both desirable traits for ‘Delicious Pilafa Tripoleos’), compared to fruits from trees in naturally occurring groundcover.
Article
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Apples are a major crop globally, including in Tasmania (Australia)-known as 'the Apple Isle' owing to the key role of apples in Tasmania's history and economy. Most apple cultivars are obligate entomophilous species, and fruit quantity, quality and economic value are enhanced under insect pollination. Whilst the introduced European honey bee (Apis mellifera) is often assumed to be the main pollinator of apple in most regions of the world, including Australia, there is an increasing interest in alternative pollinators. The pollinator community of Tasmanian apple crops, however, has never been assessed. In this study, we surveyed four apple orchards for 3 days each during peak bloom in the Huon Valley region to characterise bee assemblages visiting blooming apple trees and the native bee fauna associated with surrounding flowering vegetation. Our results show that honey bees were the predominant visitors to apple blossoms (90.7% of visits), followed by the introduced bumble bee Bombus terrestris (5.9% of visits), with only a minor contribution by native bees (3.3% of visits). Twenty-six species of native bees were collected in total, of which only 10 species (five Exoneura (Apidae), four Lasioglossum (Halictidae) and one Euryglossa (Colletidae) species) were collected from apple blossoms, with Exoneura being the most abundant visitors. Few native bees were captured on apple blossoms, however co-blooming surrounding native vegetation, as well exotic flowers, hosted a high diversity and abundance of native bees. Site conditions influenced community composition, including abundance and representation of introduced bees compared to native bees visiting apples. Additionally, warmer temperatures favoured native bees. Collectively, our results suggest that Tasmania's apple production in its current state is unlikely to rely exclusively on native pollinators. Native bees nevertheless warrant conservation in such an insular crop production system. This can be achievable through retaining native flowering plants and even exotic non-crop flowers in and around orchards. Promoting the diversity and abundance of native bees through habitat enhancement may have additional benefits, such as filling current and future pollination demands and gaps, a key strategy under scenarios of climate change.
Article
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Biological diversity could enhance ecosystem service provision by increasing the mean level of services provided, and/or by providing more consistent (stable) services over space and time. Ecological theory predicts that when an ecosystem service is provided by many species, it will be stabilized against disturbance by a variety of 'stabilizing mechanisms.' However, few studies have investigated whether stabilizing mechanisms occur in real landscapes affected by human disturbance. We used two datasets on crop pollination by wild native bees to screen for and differentiate among three stabilizing mechanisms: density compensation (negative co-variance among species' abundances); response diversity (differential response to environmental variables among species); and cross-scale resilience (response to the same environmental variable at different scales by different species). In both datasets, we found response diversity and cross-scale resilience, but not density compensation. We conclude that stabilizing mechanisms may contribute to the stability of pollination services in our study areas, emphasizing the insurance value of seemingly 'redundant' species. Furthermore, the absence of density compensation that we found at the landscape scale contrasts with findings of previous small-scale experimental and modelling work, suggesting that we should not assume that density compensation will stabilize ecosystem services in real landscapes.
Article
In this article we focus on the vital ecological services provided by insects. We restrict our focus to services provided by “wild” insects; we do not include services from domesticated or mass-reared insect species. The four insect services for which we provide value estimates—dung burial, pest control, pollination, and wildlife nutrition—were chosen not because of their importance but because of the availability of data and an algorithm for their estimation. We base our estimations of the value of each service on projections of losses that would accrue if insects were not functioning at their current level. We estimate the annual value of these ecological services provided in the United States to be at least $57 billion, an amount that justifies greater investment in the conservation of these services.
Article
To help evaluate the worth of alternative pollinators in agriculture, we present a theoretical framework for comparing the effectiveness of two or more pollinators by measuring pollen removal and deposition. We report pollen removal and deposition data by Apis mellifera and Bombus spp. during single visits to four cultivars of apples (Golden Delicious, Starkrimson Delicious, Empire/MacIntosh and Rome) and Mission almond. Apis and Bombus removed similar amounts of pollen from apple flowers but Bombus deposited more pollen on stigmas. Pollen‐collecting bees removed more pollen from apple anthers than nectar‐collecting bees. Apis that approached nectaries laterally deposited substantially less pollen than other visitors. Apis and Bombus removed and deposited similar amounts of pollen on almond flowers. Apis tended to remove more during pollen‐collecting visits than nectar‐collecting visits. The type of resource sought did not significantly influence deposition. Based on removal and deposition data, additions of Bombus may increase pollen delivery in apple orchards but reduce pollen delivery in almond orchards if Apis already serve as primary pollinators. Additional data on inter‐tree and inter‐row flights would be necessary to know how much these changes in pollen transfer might affect fertilization. Measures of pollen‐transfer effectiveness do not provide a complete assessment of pollination value, but can serve as a general, inexpensive tool for pre‐screening possible alternative pollinators.
Article
Pollinators are a key component of global biodiversity, providing vital ecosystem services to crops and wild plants. There is clear evidence of recent declines in both wild and domesticated pollinators, and parallel declines in the plants that rely upon them. Here we describe the nature and extent of reported declines, and review the potential drivers of pollinator loss, including habitat loss and fragmentation, agrochemicals, pathogens, alien species, climate change and the interactions between them. Pollinator declines can result in loss of pollination services which have important negative ecological and economic impacts that could significantly affect the maintenance of wild plant diversity, wider ecosystem stability, crop production, food security and human welfare.
Article
One of the values of biodiversity is that it may provide 'biological insurance' for services currently rendered by domesticated species or technology. We used crop pollination as a model system, and investigated whether the loss of a domesticated pollinator (the honey bee) could be compensated for by native, wild bee species. We measured pollination provided to watermelon crops at 23 farms in New Jersey and Pennsylvania, USA, and used a simulation model to separate the pollen provided by honey bees and native bees. Simulation results predict that native bees alone provide sufficient pollination at > 90% of the farms studied. Furthermore, empirical total pollen deposition at flowers was strongly, significantly correlated with native bee visitation but not with honey bee visitation. The honey bee is currently undergoing extensive die-offs because of Colony Collapse Disorder. We predict that in our region native bees will buffer potential declines in agricultural production because of honey bee losses.
The Xerces Society; right, bumble bee nest
  • Margarita Left
  • Lopez-Uribe
  • Center
  • Matthew Block
  • Shepherd
Left, cellophane bee nest, Margarita Lopez-Uribe; center, block nest, Matthew Shepherd, The Xerces Society; right, bumble bee nest, Al Eggenberger.
The Ohio State University, Bugwood. org The Xerces Society; Blue giant hyssop
  • Purple Coneflower
  • Joseph A Echinacea Purpurea
  • Lady Bird Johnson Wildflower Marcus
  • Center
  • Wild Bergamot
  • Catherine Herms Joe Monarda Fistulosa
  • Pye Weed
  • Matthew Eupatorium Purpureum
  • Shepherd
Purple coneflower, Echinacea purpurea, Joseph A. Marcus, Lady Bird Johnson Wildflower Center; Wild bergamot, Monarda fistulosa, Catherine Herms, The Ohio State University, Bugwood. org; Joe Pye weed, Eupatorium purpureum, Matthew Shepherd, The Xerces Society; Blue giant hyssop, Agastache foeniculum, Andy and Sally Wasowski, Lady Bird Johnson Wildflower Center; White meadowsweet, Spiraea alba sub. latifolia, J.S. Peterson, USDA- NRCS PLANTS Database; New England aster, Symphyotrichum novae-angliae, Pennsylvania Department of Conservation and Natural Resources, Forestry Archive, Bugwood.org.