Bee pollination services and the enhancement of fruit yield associated with seed number in self-incompatible tangelos

Solitary, dioecious, and mostly endemic to Andean cloud forests, wax palms (Ceroxylon Bonpl. ex DC. spp.) are currently under worrisome conservation status. The establishment of management plans for their dwindling populations rely on detailed biological data, including their reproductive ecology. As in the case of numerous other Neotropical palm taxa, small beetles are assumed to be selective pollinators of wax palms, but their identity and relevance in successful fruit yield were unknown. During three consecutive reproductive seasons we collected data on population phenology and reproductive and floral biology of three syntopic species of wax palms native to the Colombian Andes. We also determined the composition of the associated flower-visiting entomofauna, quantifying the extent of the role of individual species as effective pollinators through standardized value indexes that take into consideration abundance, constancy, and pollen transport efficiency. The studied populations of C. parvifrons (Engel) H. Wendl., C. ventricosum Burret, and C. vogelianum (Engel) H. Wendl. exhibit seasonal reproductive cycles with marked temporal patterns of flower and fruit production. The composition of the associated flower-visiting entomofauna, comprised by ca. 50 morphotypes, was constant across flowering seasons and differed only marginally among species. Nonetheless, a fraction of the insect species associated with pistillate inflorescences actually carried pollen, and calculated pollinator importance indexes demonstrated that one insect species alone, Mystrops rotundula Sharp, accounted for 94%–99% of the effective pollination services for all three species of wax palms. The sequential asynchronous flowering of C. parvifrons, C. ventricosum, and C. vogelianum provides an abundant and constant supply of pollen, pivotal for the maintenance of large populations of their shared pollinators, a cooperative strategy proven effective by high fruit yield rates (up to 79%). Reproductive success might be compromised for all species by the population decline of one of them, as it would tamper with the temporal orchestration of pollen offer.

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Organic Establishment of Pollination Reservoirs in the Lowbush Blueberry (Ericales: Ericaceae) Agroecosystem

Open Agriculture ◽

10.1515/opag-2018-0044 ◽

2018 ◽

Vol 3 (1) ◽

pp. 393-403 ◽

Cited By ~ 3

Author(s):

E. M. Venturini ◽

F. A. Drummond ◽

A. K. Hoshide

Keyword(s):

Economic Analysis ◽

Coniferous Forest ◽

Cropping System ◽

Bee Pollination ◽

Pollination Services ◽

Wild Bee ◽

Lowbush Blueberry ◽

Native Bee ◽

Wild Blueberries ◽

Nurse Crops

Abstract Pollination reservoirs are pollen and nectar rich wildflower plantings intended to enhance pollination services in pollinator-dependent crops. Despite government assistance, plantings often fail to establish. Our focal crop, wild blueberries, is a unique cropping-system native to the U.S.A. It is never planted or cultivated, and typically exists in isolated fields within a mostly coniferous forest matrix. Our study takes place in Maine, U.S.A., where growers could economically benefit by switching reliance from rented honey bees to native bee pollination. Lowbush blueberry growers support wild bee enhancement efforts, but the low pH (4.0-5.0) of this agro-ecosystem presents unique challenges to wildflower establishment. We sought to identify methods that Organic certified growers can use to successfully establish pollination reservoirs in this system. We tested the effects of nurse crops and mowing on the success of a custom wildflower mixture over four years. Success was considered in terms of longevity, sown species diversity, above-ground biomass, and the number and weight of inflorescences. The authors present an economic analysis of cost versus projected planting longevity. In the fourth year of establishment, sown plant diversity significantly decreased, Solidago spp. weeds became dominant, and treatments were not a strong determinant of planting success. The economic analysis suggests that the high cost of pollination reservoir establishment may be a barrier to grower adoption. This study provides evidence and economic justification that weeds must be controlled prior to planting and represents one of the first studies to empirically test organic strategies for wildflower establishment in an agricultural context.

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Pollination Services from Insects in Homegardens in the Chengdu Plain will be Confronted with Crises

Sustainability ◽

10.3390/su11072169 ◽

2019 ◽

Vol 11 (7) ◽

pp. 2169 ◽

Cited By ~ 2

Author(s):

Qin Liu ◽

Pei Xu ◽

Kun Yan ◽

Yingman Guo

Keyword(s):

Agricultural Production ◽

Peak Time ◽

Bee Pollination ◽

Insect Pollination ◽

Peach Fruit ◽

Pollination Services ◽

Chengdu Plain ◽

Yield And Quality ◽

Field Investigations ◽

Flower Visiting

Chengdu Plain is one of China’s most important agricultural production zones and has a large human population. Agricultural crops require insect pollination to increase yield and quality, which is especially important in plains areas where forest area is small. Homegardens are the main habitat of pollinators. The present study identified the importance of insect pollination in homegardens in the Chengdu Plain through field investigations and comparative experiments and revealed the risk to pollination services caused by the decrease in diversity and population of managed and wild pollinators. The results showed that (1) prohibiting all insect pollination (treatment A) and prohibiting managed bee pollination (treatment B) significantly reduced the yield and seed number of rapeseed and significantly reduced the size, weight, and sweetness of peach fruit, but had no significant effects on plums; (2) the dependence on insect pollination and the economic values of insect pollination for rapeseed and peaches are 0.56 and $85.1 million and 0.44 and $31.0 million, respectively; (3) there were 23 flower-visiting pollinator species at the experimental sites including: four species of managed bees and 19 species of wild pollinators. The peak time for pollinators to visit flowers was 11:00 to 15:00, and the managed bees accounted for over 67.55% of these visits; (4) within a radius of 1000 m from the site, 58.06% of the bees were non-locally managed, and the bee population managed locally by farmers decreased; and (5) compared with 2008, the number of homegardens decreased by 17.24%, the managed bees within the homegardens decreased by 62.05%, and the disappearance and destruction of homegardens led to a significant reduction in wild pollinators.

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Wild Bee Visitation Rates Exceed Pollination Thresholds in Commercial Cucurbita Agroecosystems

Journal of Economic Entomology ◽

10.1093/jee/toz295 ◽

2019 ◽

Vol 113 (2) ◽

pp. 562-574 ◽

Cited By ~ 4

Author(s):

C M McGrady ◽

R Troyer ◽

S J Fleischer

Keyword(s):

Management Strategies ◽

Field Size ◽

Bee Pollination ◽

Wild Bees ◽

Temporal And Spatial Variation ◽

Pollination Services ◽

Wild Bee ◽

Visitation Rates ◽

Field Edge ◽

Temporal And Spatial

Abstract Wild bees supply sufficient pollination in Cucurbita agroecosystems in certain settings; however, some growers continue to stock fields with managed pollinators due to uncertainties of temporal and spatial variation on pollination services supplied by wild bees. Here, we evaluate wild bee pollination activity in wholesale, commercial pumpkin fields over 3 yr. We identified 37 species of bees foraging in commercial pumpkin fields. Honey bees (Apis mellifera L. [Hymenoptera: Apidae]), squash bees (Eucera (Peponapis) Say, Dorchin [Hymenoptera: Apidae]), and bumble bees (Bombus spp., primarily B. impatiens Cresson [Hymenoptera: Apidae]) were the most active pollinator taxa, responsible for over 95% of all pollination visits. Preference for female flowers decreased as distance from field edge increased for several bee taxa. Visitation rates from one key pollinator was negatively affected by field size. Visitation rates for multiple taxa exhibited a curvilinear response as the growing season progressed and responded positively to increasing floral density. We synthesized existing literature to estimate minimum ‘pollination thresholds’ per taxa and determined that each of the most active pollinator taxa exceeded these thresholds independently. Under current conditions, renting honey bee hives may be superfluous in this system. These results can aid growers when executing pollination management strategies and further highlights the importance of monitoring and conserving wild pollinator populations.

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Bee Pollination Highly Improves Oil Quality in Sunflower

Sociobiology ◽

10.13102/sociobiology.v65i4.3367 ◽

2018 ◽

Vol 65 (4) ◽

pp. 583

Author(s):

Carina A. S. Silva ◽

Wesley A. C. Godoy ◽

Cynthia R. O. Jacob ◽

Gustavo Thomas ◽

Gil M. S. Câmara ◽

...

Keyword(s):

Fatty Acids ◽

Vitamin E ◽

Unsaturated Fatty Acids ◽

Oil Quality ◽

Nutritional Composition ◽

Bee Pollination ◽

Pollination Services ◽

Agricultural Industry ◽

Exclusion Experiments ◽

Bee Community

Sunflower is a pollinator-dependent crop and one of the most cultivated oilseeds in the world, supporting important sectors of the agricultural industry, such as the food supply, because it is an important source of vitamin E and unsaturated fatty acids for human health. Although it is well stablished that bee pollination improves sunflower seed set, it is still unknown if pollinators influence the nutritional composition. Considering the economic importance of sunflowers for several Brazilian agricultural sectors, the aim of this study was to evaluate the effect of the bee community for (1) achene quality (weight and nutritional composition) and (2) market value. Exclusion experiments were performed with hybrid sunflowers and showed that bee pollination enhanced the achene weight by 91 %, the levels of vitamin E by 45 % and unsaturated fatty acids by 0.3 %. Also, it was estimated that due to the pollination services provided by bees, the grower of the sunflower cultivar used in this study nearly duplicates the sale value of the achenes per hectare of cultivated area. Thus, the current study highlights the importance of bees as providers of cross- and self-pollination to nutritional quality of sunflower achenes and provides useful baseline figures to further evaluations of the effects of pollinators on human diets and health.

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Pollination and Plant Reproductive Success of Two Ploidy Levels in Red Clover (Trifolium pratense L.)

Frontiers in Plant Science ◽

10.3389/fpls.2021.720069 ◽

2021 ◽

Vol 12 ◽

Author(s):

Shuxuan Jing ◽

Per Kryger ◽

Bo Markussen ◽

Birte Boelt

Keyword(s):

Reproductive Success ◽

Honey Bee ◽

Red Clover ◽

Flower Head ◽

Seed Number ◽

Bee Pollination ◽

Ploidy Levels ◽

Plant Reproductive Success ◽

Visitation Rates ◽

Hand Pollination

Plant reproduction in red clover requires cross-fertilization via insect pollination. However, the influences of visitation rate and timing on maximizing ovule utilization are yet to be determined. We aimed to study the influences of visitation rate, flowering stage, and self-incompatibility on reproductive success. We applied hand and honey bee pollination in the study of eight red clover cultivars with two ploidy levels released between 1964 and 2001. In hand pollination, increasing the visitation rates (from 10 to 80 pollinated florets per flower head) increased the seed number per flower head but reduced the seed number per pollinated floret. Different flowering stages (early, middle, and full flowering) did not influence the seed number per pollinated floret significantly. There was a marked difference in reproductive success depending on the ploidy level, with 0.52 seeds per pollinated floret in diploid and 0.16 in tetraploid cultivars. During the cultivar release history, seed number per pollinated floret seemed to decrease in diploid cultivars, whereas it increased in tetraploids. In honey bee pollination, diploid cultivars had more two-seeded florets than tetraploids. Different visitation rates and the stochastic nature of pollen transfer resulted in difficulties when the plant reproductive success between hand and bee pollination was compared. A maximum of 0.27 seeds per pollinated floret were produced in hand pollination compared to the 0.34 in honey bee pollination. In spite of this, hand pollination provided a valuable method for studying the pollination biology and reproduction of red clover. Future studies may employ hand pollination to unravel further aspects of the low reproductive success with the future perspective of improving seed number per pollinated floret in tetraploid red clover.

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