Evaluating the attractiveness of Coreopsis spp.
wild types and cultivars to pollinators.
Owen Cass and Dr. Deborah A. Delaney, University of Delaware, Newark, DE
Introduction
Results
Results
Popular garden plants often have a multitude of cultivars. A
cultivar has been selected for favorable characteristics such as floral
display, disease resistance, or in the case of food plants, flavor and
yield. Cultivars can be a superior selection of a species, a hybrid
cross of two species, or a complex hybrid that arose from many
generations of cross breeding. An asexually propagated cultivar
population lacks genotypic variation. Whereas an open-pollinated
plant population has genotypic variation and is “free” to undergo
natural selection. The distinction between the methods of breeding
and propagating cultivars and wild-type species may impact how
each functions in the ecosystem. This project is driven by a primary
question: Does pollinator diversity and abundance vary among
different wild-type species and derived cultivars of a flowering plant
genus?
Cultivars are propagated by humans which implies they do
not necessarily require a fully functioning reproductive system. The
patents for Coreopsis ‘Salsa’ and Coreopsis ‘Little Penny’, both
included in this evaluation, state that no seeds are produced
(Korlipara 2008, Probst 2011). Seed of course is necessary for
reproduction and is a valuable food source for animals such as birds
and insects. Frankie et al. (2005) suggested that the selection of
aesthetically pleasing plants without regard for insect visitors may
reduce the usefulness and attractiveness of the flower for
pollinators.
In addition to quantifying pollinator visitation to Coreopsis spp.,
we will be measuring pollen production, pollen nutritional content,
nectar production, and comparing different methods to sample
pollinators. This poster presents results on the observed pollinators
per flower and floral syndromes. The overall goal of this project is to
help gardeners and growers make informed decisions when
choosing native plants for the landscape.
Early season observations: June 27, 2014 to July 16, 2014.
Late season observations: July 17, 2014 to August 27, 2014
0.0035
0.014
0.003
0.0025
0.002
0.0015
0.012
C. 'Little Penny'
C. 'Jive'
C. 'Salsa'
C. 'Pineapple Pie'
C. 'Golden Dream'
C. 'Lacy Lingerie'
C. 'Moonbeam'
C. 'Golden Gain'
C. 'Route 66'
C. 'Full Moon'
C. 'Zagreb'
C. 'verticillata'
0.01
0.008
0.006
0.001
0.004
0.0005
0.002
0
0
Figure 1. Bars represent the grand mean pollinators per flower observed on 12 plant types between 6/27/2014
and 7/16/2014 at the Mt. Cuba Center trial garden. Colors represent the proportional contribution of each
plant type to the grand mean.
0.8
C. 'Salsa'
C. rosea
C. 'Redshift'
C. 'Pineapple Pie'
C. 'Moonbeam'
C. major
C. 'Little Penny'
C. 'Golden Dream'
C. 'Full Moon'
C. delphinifolia
C. 'Center Stage'
C. 'Jive'
C. 'Salsa'
0.2
0.4
C. 'Star Cluster'
C. 'Little Penny'
C. 'Salsa'
C. 'Show Stopper'
C. 'Redshift'
C. rosea
C. 'Pineapple Pie'
C. 'Moonbeam'
C. ‘Jive’
0
C. 'Center Stage'
C. 'Full Moon'
0
C. 'Golden Dream'
C. verticillata
C. 'Full Moon'
C. 'Pineapple Pie'
C. 'Moonbeam'
-0.1
C. major
C. 'Zagreb'
-0.2
-0.2
C. 'Golden Gain'
-0.4
C. 'Lacy Lingerie'
C. 'Golden Dream'
-0.3
Discussion
C. 'Little Penny'
C. 'Route 66'
-0.6
0.8
1
-0.4
-0.4
0.1
0.2
0.3
0.4
A
A
A
0.015
B
BC BC
0.005
D
E
0
CD
D
DE
E
E
E
C. 'Redshift'
C. 'Show Stopper'
C. major
C. 'Center Stage'
C. 'Full Moon'
C. 'Star Cluster'
C. 'Pineapple Pie'
C. 'Golden Dream'
C. 'Moonbeam'
C. 'Little Penny'
C. rosea
C. 'Jive
C. delphinifolia
C. 'Salsa'
0
Figure 9. Mean number of dark bees per flower observed on 14
plant types between 7/17/2014 and 8/27/2014 at the Mt. Cuba
Center trial garden. Error bars are standard error. Plant types sharing
the same letter were not significantly different (p>0.05, Wilcoxon
Signed-Rank test).
Mean wasps per flower on late season
Coreopsis spp.
Mean honey bees per flower on late
season Coreopsis spp.
A
C. ‘Lacy Lingerie
Coreopsis verticillata
Coreopsis ‘Show Stopper’
0
Figure 5. Mean number of honey bees per flower observed on 12 plant
types between 6/27/2014 and 7/16/2014 at the Mt. Cuba Center trial
garden. Error bars are standard error. Plant types sharing the same
letter were not significantly different (p>0.05, Wilcoxon Signed-Rank
test).
D
D
D
D
D
E
D
Figure 10. Mean number of honeybees per flower observed on 14
plant types between 7/17/2014 and 8/27/2014 at the Mt. Cuba
Center trial garden. Error bars are standard error. Plant types
sharing the same letter were not significantly different (p>0.05,
Wilcoxon Signed-Rank test).
DE CD
DE
E
0
DE
C. 'Salsa'
D
C
0.001
C. delphinifolia
E
References
C. 'Jive
C. 'Pineapple Pie'
C. 'Golden Dream'
C. 'Lacy Lingerie'
C. 'Moonbeam'
C. 'Golden Gain'
C. 'Route 66'
C. 'Full Moon'
C. 'Zagreb'
C. 'verticillata'
Coreopsis ‘Zagreb’
C
CDE
C. rosea
E
E
BCD
0.002
C. 'Little Penny'
Coreopsis ‘Golden Dream’ Coreopsis major
0.005
Acknowledgements
B
C. 'Moonbeam'
BCDE
D
CD
C. 'Golden Dream'
0.003
DE
BCD
AB
0.003
C. 'Center Stage'
CDE
AB
ABC
0.004
C. major
BCD
0.01
AB
ABC
C. 'Show Stopper'
BCD
0.015
C. 'Redshift'
B
0.005
C. 'Redshift'
C. 'Show Stopper'
C. major
C. 'Center Stage'
C. 'Full Moon'
C. 'Star Cluster'
C. 'Pineapple Pie'
C. 'Golden Dream'
C. 'Moonbeam'
C. 'Little Penny'
C. rosea
C. 'Jive
C. delphinifolia
C. 'Salsa'
0.006
AB
Mean wasps per flower
B
0
C. ‘Golden Gain’
Mean honey bees per flower
0.009
C. 'Little Penny'
Coreopsis ‘Little Penny’
C. 'Jive'
Coreopsis delphinifolia
Coreopsis ‘Salsa’
C. 'Salsa'
Coreopsis rosea
Coreopsis ‘Moonbeam’
Mean honey bees per flower
A
Clear variation in preference for certain Coreopsis types was
displayed by the different pollinator groups. Analysis of the floral
syndrome (plant height, flower size, flower color, nectar accessibility,
pollen production etc.), time of day, and local weather as predictors
of pollinator visitation will be performed to help explain the
differences in visitation.
Bumble bees visiting late season Coreopsis spp. showed
strong preference for C. ‘Redshift’, C. ‘Show Stopper’, C. ‘Center
Stage’ and C. major; moderate preference for C. ‘Full Moon’, C. ‘Star
Cluster’, and C. ‘Pineapple’; and little preference for the rest. No
bumble bees were detected on C. ‘Salsa’ during 78 minutes of
observations (n=26). This does not necessarily mean C. ‘Salsa’ is a
not a good plant for pollinators.
C. ‘Jive’ and C. ‘Salsa’ are both derived from Coreopsis rosea and
all 3 had similar pollinator communities (Figure 7) and mean
pollinators per flower (Figures 8, 9, 10, 11). However, C. ‘Salsa’ and
C. ‘Jive’ do not set seed and are annuals. Aside from pollinator
visitation, those traits should be considered when evaluating the
ecological services of a plant.
Pollinators exhibit differential preference for Coreopsis spp. For
concerned gardeners, the sort of detailed information presented
here may help guide decisions on what plants to install and help
them understand the interaction that their garden has with the
surrounding ecosystem.
This project was wholly funded by the Mt. Cuba Center, located
in Hockessin, Delaware. The Mt. Cuba Center is dedicated to
inspiring an appreciation for the beauty and value of native plants
and a commitment to protect the habitats that sustain them.
Many people assisted with this project including Christina
Mitchell, James Wolfin, Sabrina Lessner, and George Coombs.
Thanks to the lab group for encouragement and support: David
Gardner, Katy Evans, Dr. Deborah Delaney, and Grace Savoy-Burke.
0.006
0.02
A
DE
E
0.005
CD
E
Figure 8. Mean number of bumble bees per flower observed on
14 plant types between 7/17/2014 and 8/27/2014 at the Mt.
Cuba Center trial garden. Error bars are standard error. Plant
types sharing the same letter were not significantly different
(p>0.05, Wilcoxon Signed-Rank test).
0.015
BC
C
C. 'Salsa'
D
0.01
C. delphinifolia
D
BC
C. 'Jive
D
0.015
C. rosea
CD
AB
C. 'Little Penny'
0.01
0.02
C. 'Moonbeam'
0.02
0.025
C. 'Golden Dream'
A
Mean honey bees per flower on early
season Coreopsis spp.
Coreopsis ‘Jive’
0.6
0.03
0.025
Figure 4. Mean number of dark bees per flower observed on 12
plant types between 6/27/2014 and 7/16/2014 at the Mt. Cuba
Center trial garden. Error bars are standard error. Plant types
sharing the same letter were not significantly different (p>0.05,
Wilcoxon Signed-Rank test).
0.012
0.5
Mean dark bees per flower on late
season Coreopsis spp.
A
0.03
C. 'Little Penny'
C. 'Jive'
C. 'Salsa'
DE
0
Figure 3. Mean number of bumble bees per flower observed on
12 plant types between 6/27/2014 and 7/16/2014 at the Mt.
Cuba Center trial garden. Error bars are standard error. Plant
types sharing the same letter were not significantly different
(p>0.05, Wilcoxon Signed-Rank test).
D
Mean bumble bees per flower
DE
C. 'Pineapple Pie'
C
0.002
C. 'Golden Dream'
C. 'Pineapple Pie'
C. 'Golden Dream'
C. 'Lacy Lingerie'
C. 'Moonbeam'
C. 'Golden Gain'
C. 'Route 66'
C. 'Full Moon'
C. 'Zagreb'
C. 'verticillata'
0
C
BCD
CDE
C. 'Route 66'
C
BCE
C. 'verticillata'
C
C
C
BC
0.004
C. 'Little Penny'
C
BC
C. 'Jive'
0.002
C
ABCDE
C. 'Full Moon'
AB
ABC ABC
C. 'Lacy Lingerie'
0.004
0.006
C. 'Moonbeam'
ABC
ABC
ABC
C. 'Zagreb'
0.006
0.008
C. 'Golden Gain'
Mean dark bees per flower
0.008
0
Mean bumble bees per flower on
late-season Coreopsis spp.
0.01
A
C. 'Salsa'
Mean bumble bees per flower
0.01
-0.1
Figure 7: Distance between points represents dissimilarity between pollinator communities observed visiting
14 types of Coreopsis spp. between 7/17/2014 and 8/27/2014 at the Mt. Cuba Center trial garden. Non-metric
multidimensional scaling of Bray-Curtis dissimilarity index was employed.
Mean dark bees per flower on earlyseason Coreopsis spp.
Mean bumble bees per flower on
early season Coreopsis spp.
-0.2
C. 'Pineapple Pie'
Figure 2: Distance between points represents dissimilarity between pollinator communities observed
visiting 12 types of Coreopsis spp. between 6/27/2014 and 7/16/2014 at the Mt. Cuba Center trial
garden. Non-metric multidimensional scaling of Bray-Curtis dissimilarity index was employed.
-0.3
C. 'Pineapple Pie'
0.6
C. 'Star Cluster'
0.4
C. 'Star Cluster'
0.2
C. 'Full Moon'
0
C. 'Center Stage'
-0.2
C. major
-0.4
C. 'Show Stopper'
-0.6
C. 'Redshift'
-0.8
Mean dark bees per flower
-1
C. 'Full Moon'
Coreopsis ‘Route 66’
Within the early season Coreopsis spp., C. ‘Lacy Lingerie’
attracted significantly more bumble bees per flower than the
straight species, C. verticillata (Figure 3).
C. ‘Golden Gain’, C. ‘Golden Dream’ and C. ‘Little Penny’
attracted significantly less dark bees per flower than the straight
species, C. verticillata (Figure 4).
C. ‘Route 66’ attracted significantly more honey bees per flower
than all the other Coreopsis spp. (Figure 5).
Within the late season Coreopsis spp. observations, C. ‘Redshift’,
C. ‘Show Stopper’, C. major, and C. ‘Center Stage’ all attracted
significantly more bumble bees per flower than the other Coreopsis
spp. (Figure 8).
Coreopsis rosea and its two derived cultivars, C. ‘Jive’ and C.
‘Salsa’, maintained similar pollinator communities (Figure 7). All
three had very low visitation from bumble bees and honey bees
(Figure 3, 8, 5, and 10). The mean number of dark bees was
moderate within this group (Figure 9)
Although superficially similar plants, C. ‘Salsa’ and C. ‘Pineapple
Pie’ were significantly different in the mean observed bumble bees,
wasps, and dark bees per flower (Figures 8 and 9).
Simultaneous vacuum sampling revealed the dark bees to be
95.4% Halictidae, 2.7% Andrenidae, 0.8% Apidae, 0.5% Colletidae,
0.5% Megachilidae, and 0.1% Crabronidae (n=2151).
0.3
0.2
From June
to August
, 2014, four wild species and
thirteen cultivars from the genus Coreopsis (Asteraceae) were
evaluated for pollinator visitation and floral characteristics. The
Coreopsis plants were growing in the Mt. Cuba Center trial garden
(Hockessin, Delaware). The trial garden is part of 500 acres of land
managed by Mt. Cuba Center with an emphasis on native plants and
ecosystems. The Coreopsis genus was selected because it is native
to North America and a great number of cultivars are available on
the market.
Non-destructive sampling was performed by marking a 0.6
meter square near the center of each flower patch. On each
sampling date, the patch was photographed and the number of
open flowers counted. Every 15 seconds for 3 minutes the number
of each insect type that contacted the upper surface of a flower
head was recorded into one of the following groups: honey bee,
bumble bee, large carpenter bee, green sweat bee, Megachilidae,
[unknown] dark bee, Coleoptera, Syrphidae, Diptera, Lepidoptera,
or wasp. The number of visits by each pollinator type over the 3
minutes observation was averaged for that period and divided by
the number of flowers to give mean pollinators per flower.
Flower measurements (petal color, maximum flower
diameter, disc portion diameter, and disc florets per head) were
taken on July 3rd, 2014.
Due to considerable variation in the overall pollinator
community and plant flowering periods throughout the season, the
plants being evaluated were split into two groups. The early season
group includes samples from June 27, 2014 to July 16, 2014. The
late season group includes samples from July 17, 2014 to August 27,
2014.
C. ‘Pineapple Pie’
C. 'Show Stopper'
0.4
0.6
27th
Coreopsis ‘Star Cluster’
C. 'Star Cluster'
C. delphinifolia
Methods
Coreopsis ‘Center Stage’
Jive
Figure 6. Bars represent the grand mean pollinators per flower observed on 14 plant types between 7/17/2014
and 8/27/2014 at the Mt. Cuba Center trial garden. Colors represent the proportional contribution of each
Coreopsis spp. to the grand mean.
0.1
27th
Table 1. Floral characteristics of each Coreopsis spp. taken on July 3rd, 2014 at the Mt. Cuba
Center trial garden. (n=) early season and (n=) late season are the number of pollinator
observations performed on each Coreopsis spp. during each time period.
Diameter Disc portion
Disc flowers
Petal Color (n=) early (n=) late
Coreopsis Type
(cm)
diameter (cm) per head
Distal - Basal season season
C. 'Route 66'
3.99 ± 0.16 0.68 ± 0.025 60.8 ± 3.9
11
C. 'Lacy Lingerie' 3.27 ± 0.31 0.64 ± 0.081 49.4 ± 1.9
10
C. verticillata
2.88 ± 0.20 0.57 ± 0.056 47.5 ± 3.5
11
C. 'Golden Dream' 2.33 ± 0.14 0.34 ± 0.043 119.4 ± 6.8
11
C. 'Golden Gain' 4.12 ± 0.42 0.62 ± 0.056 32.7 ± 2.2
8
C. 'Full Moon'
4.69 ± 0.35 0.87 ± 0.068 107.4 ± 9.4
11
15
C. 'Little Penny' 1.27 ± 0.08 0.34 ± 0.031 43.2 ± 7.4
11
15
C. 'Salsa'
2.5 ± 0.09 0.61 ± 0.056 101.8 ± 5.1
11
15
C. rose
2.13 ± 0.09 0.58 ± 0.025 72.8 ± 3.8
10
C . 'Jive'
2.66 ± 0.13 0.71 ± 0.037 121.3 ± 9.7
11
15
C. 'Moonbeam' 2.94 ± 0.21 0.59 ± 0.043 56.7 ± 4.8
11
15
C. 'Pineapple Pie' 3.26 ± 0.11 0.83 ± 0.056 148.1 ± 12.0
11
15
C. 'Star Cluster' 3.48 ± 0.29 0.98 ± 0.124 128.1 ± 7.4
15
C. major
4.16 ± 0.10 0.93 ± 0.031 43.2 ± 4.2
15
C. delphinifolia
4.29 ± 0.09 0.91 ± 0.043 133.6 ± 3.3
15
C. 'Show Stopper' 4.35 ± 0.15 0.93 ± 0.031 98.6 ± 4.7
15
C. 'Center Stage' 4.38 ± 0.25 0.89 ± 0.068 106.1 ± 4.5
13
C. 'Redshift'
4.45 ± 0.26 1.05 ± 0.031 127.9 ± 12.2
15
Figure 11. Mean number of wasps per flower observed on 14 plant
types between 7/17/2014 and 8/27/2014 at the Mt. Cuba Center
trial garden. Error bars are standard error. Plant types sharing the
same letter were not significantly different (p>0.05, Wilcoxon
Signed-Rank test).
Frankie, G. W., Thorp, R. W., Schindler, M., Hernandez, J., Ertter, B., &
Rizzardi, M. (2005). Ecological Patterns of Bees and Their Host
Ornamental Flowers in Two Northern California Cities. Journal of
the Kansas Entomological Society.
Korlipara, Harini. (2008). Coreopsis Plant Named ‘RP1’ Terra Nova
Nurseries. Patent USPP18502 P2. 18 Feb. 2008.
Probst, Darrell R. (2011). Coreopsis Plant Named 'Salsa' Darrell
Probst, assignee. Patent USPP22129 P2. 6 Sept. 2011.