scholarly journals Consequences of the high abundance of Bombus terrestris on the pollination of Vicia faba

2021 ◽  
Vol 29 ◽  
Author(s):  
Cecilia Smith ◽  
Adriana Rendón ◽  
Rodrigo Barahona ◽  
Wladimir Moya

One of the main visitors to Fabia bean crops (Vicia faba) in South America is the invasive bumblebee species Bombus terrestris. This is particularly true in Chile, where B. terrestris was first introduced in 1997 and is now common over much of the country. In this study, we evaluated the activity of the principal pollinators of V. faba over two cropping seasons by assessing their visitation rates while distinguishing between legitimate visits, likely to lead to pollination, and nectar robbery. We then determined the net contribution of insect visitation on pod and seed set. We recorded seven species of floral visitors. Most visits (legitimate visits and robbery) were from the honeybee (Apis mellifera), with B. terrestris being the next most common visitor. In the case of B. terrestris, 87.19% of visits were nectar robbery. On average, the same flower perforation was visited 23 times by B. terrestris during the flower's lifespan. In general, the frequency of legitimate visits varied with pollinator identity and year. For B. terrestris, each flower received an average of 0.95 legitimate visits during its entire lifespan. The time spent by B. terrestris visiting flowers for both nectar robbery or pollen collection decreased after the first day of flowering suggesting resource depletion. The number of pods, total seed number, and seed weight were lower where self rather than open pollination. This suggests that open pollination increased reproductive success. We conclude that B. terrestris was likely to contribute relatively little to pollination while at the same time depleting floral resources throughout the flowers’ lifespan.

Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1088
Author(s):  
Mohamed Houssemeddine Sellami ◽  
Antonella Lavini ◽  
Davide Calandrelli ◽  
Giuseppe De Mastro ◽  
Cataldo Pulvento

Faba beans (Vicia faba L.), also known as fava beans, like other crops, are influenced by several factors: their genotype, environment, and management, as well as the interaction between these, have an important impact on seed yielding and seed quality traits. This study was conducted at three locations in South Italy between 2017 and 2019 to evaluate the sowing date effect on yield and yield components of three Vicia faba L., originating from cool climates. The results showed that seed yield (SY) and yield components declined with sowing delay. The crop’s environment (year × site) and management (sowing date) were found to explain 34.01% and 42.95% of the total seed yield variation, respectively. The data showed that the tested genotypes were positively influenced by the environment with sandy loam soil and early winter sowing date, resulting in either a greater number of SY and THS than in the other environment. The three faba bean genotypes showed tolerance to winter frost conditions in the two growing seasons.


Author(s):  
A. Ouji ◽  
S. Chekali ◽  
M. Rouaissi

Background: In Tunisia, faba bean (Vicia faba L.) is the first major food legume. The development of faba bean production is facing several biotic constraints. Faba bean Ascochyta blight caused by Ascochyta fabae is one of the most destructive diseases of faba bean and can cause significant yield loss under favorable conditions. As only incomplete resistance ABL varieties are available, some agronomic practices should be applied to control and reduce Ascochyta blight incidence wherever possible. Therefore, this work was undertaken to evaluate the effect of spacing row and seed rate on ABL severity, growth and yield of faba bean. Methods: A split-plot design with three replications was adopted to carry out this study during 2018 and 2019 cropping seasons. ‘Bachaar’ faba bean variety was sown at 40 and 60 cm row spacing and at three seed rates (100, 140 and 200 kg ha-1). ABL severity was assessed visually on a 0-9 scale and agro-morphological traits were measured. Analysis of variance was used to analyze the data. Correlations between agronomic traits, row spacing, seed rate and ABL severity were investigated. Result: Results showed that seed rate has a larger effect on yield than row spacing. In both cropping seasons, the highest grain yield was recorded in 60 cm row spacing and 140 kg ha-1 seed rate treatment. So, this treatment is recommended for obtaining high yield of faba bean. Most of the variation in disease severity was associated with seed rate (r=0.62). The highest ABL score severity was noted at 200 kg ha-1 rate. Over both years, wide row spacing and low seed rate reduced ABL severity. In this study, the small amounts of ABL disease (which reached a score of 5.3 and 4.7 in 2018 and 2019, respectively) had little or no effect on yield.


2021 ◽  
Author(s):  
Júlia Mendonça Almeida ◽  
Caio César Corrêa Missagia ◽  
Maria Alice Santos Alves

Abstract Many plants pollinated by nectar-foraging animals have to maintain a balance between legitimate visitor attraction strategies and mechanisms that minimize illegitimate visits. This study investigated how floral display and neighboring species composition influences nectar robbing in the tropical ornithophilous herb Heliconia spathocircinata. We tested the role of inflorescence display, flower abundance, and neighboring species in the reduction of nectar robbing in H. spathocircinata. Our results indicate that nectar robbing hummingbird activity was higher in moderately large inflorescence displays and that the frequency of nectar robbing in H. spathocircinata decreases with increased flower abundance and the presence of neighboring plant species. Neighboring non-ornithophilous plants decreased the frequency of nectar robbing in H. spathocircinata flowers to a greater extent than ornithophilous ones. These results suggest that nectar robbing hummingbirds are attracted to similar conditions that attract legitimate visitors, and that spatial aggregation and mixed-species displays may represent a mechanism to dilute nectar robbing effects at an individual level.


Apidologie ◽  
1994 ◽  
Vol 25 (3) ◽  
pp. 338-349 ◽  
Author(s):  
S. Carré ◽  
I. Badenhausser ◽  
J. N. Taséi ◽  
J. Le Guen ◽  
J. Mesquida

Agronomy ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1993
Author(s):  
Philipp W. Eckerter ◽  
Lars Albus ◽  
Sharumathi Natarajan ◽  
Matthias Albrecht ◽  
Lolita Ammann ◽  
...  

Wild bumblebees are key pollinators of crops and wild plants that rely on the continuous availability of floral resources. A better understanding of the spatio-temporal availability and use of floral food resources may help to promote bumblebees and their pollination services in agricultural landscapes. We placed colonies of Bombus terrestris L. in 24 agricultural landscapes with various degrees of floral resource availability and assessed different parameters of colony growth and fitness. We estimated pollen availability during different periods of colony development based on detailed information of the bumblebee pollen diet and the spatial distribution of the visited plant species. Total pollen availability did not significantly explain colony growth or fitness. However, when using habitat maps, the weight gain of colonies, the number of queen cells, and colony survival decreased with increasing distance from the forest. The better explanation of bumblebee performance by forest proximity than by (plant-inferred) pollen availability indicates that other functions of forests than pollen provision were important. The conservation of forests next to agricultural land might help to sustain high populations of these important wild pollinators and enhance their crop pollination services. Combining different mapping approaches might help to further disentangle complex relationships between B. terrestris and their environment in agricultural landscapes.


2020 ◽  
Vol 74 (12) ◽  
Author(s):  
Veronica R. Wignall ◽  
Matthew Brolly ◽  
Cassandra Uthoff ◽  
Kala E. Norton ◽  
Hannah M. Chipperfield ◽  
...  

Abstract Eusocial bees are likely to be ecologically important competitors for floral resources, although competitive effects can be difficult to quantify in wild pollinator communities. To investigate this, we excluded honeybees (HBE treatment), bumblebees (BBE) or both (HB&BBE) from wild-growing patches of bramble, Rubus fruticosus L. agg., flowers in two eight-day field trials at separate locations, with complementary mapping of per-site local floral resource availability. Exclusions increased per-flower volume of nectar and visitation rates of non-excluded bees, compared to control patches with no bee exclusions (CON). There was a large increase in average nectar standing crop volume both at Site 1 (+ 172%) and Site 2 (+ 137%) in HB&BBE patch flowers, and no significant change in HBE or BBE, compared to CON patches. Foraging bee responses to exclusion treatments were more pronounced at Site 2, which may be due to lower local floral resource availability, since this is likely to increase the degree of exploitative competition present. Notably, at Site 2, there was a 447% increase in larger-bodied solitary (non-Apis/Bombus) bees visiting HB&BBE patches, suggesting ecological release from competition. Hoverflies showed no response to bee removals. Numbers of other non-bee insect groups were very small and also showed no clear response to exclusions. Our findings reveal patterns of competitive exclusion between pollinator groups, mediated by resource depletion by eusocial bees. Possible long-term implications of displacement from preferred flowers, particularly where alternative forage is reduced, are discussed. Significance statement Understanding patterns of exploitative competition and displacement is necessary for pollinator conservation, particularly for vulnerable or threatened species. In this research, experimental methods reveal underlying patterns of resource competition exerted by eusocial bees in a wild pollinator community. We show that honeybees and bumblebees competitively displace each other and particularly solitary (non-Apis/Bombus) bees from bramble, an important native nectar and pollen source. Effects were stronger where local floral resource availability was identified to be limited. Notably, following experimental exclusion of both honey- and bumblebees from flowers, visitation by solitary bees increased by up to 447%, strongly suggesting ecological release from competition. These results highlight the need for informed landscape management for pollinator wellbeing, including appropriate honeybee stocking densities and improved floral resource availability.


2017 ◽  
Vol 70 ◽  
pp. 52-57 ◽  
Author(s):  
B.G. Howlett ◽  
S.F.J. Read ◽  
L.K. Jesson ◽  
A. Benoist ◽  
L.E. Evans ◽  
...  

Different pollinators may vary in their temporal flower-visitation patterns within crops, potentially extending the period pollination may occur. To assess whether this could be the case in kiwifruit, we conducted standardised observational surveys of insects visiting kiwifruit flowers within 31 orchards at three times: 10:00—11:00, 12:00—13:00 and 14:00—15:00 hr. Honey bees (Apis mellifera) represented 92% of visitations (n=5474), but temporal abundances were uneven (predicted abundances were lower at 14:00—15:00 hr). Predatory hover flies (Melangyna, Melonostoma, Allograpta spp.) also showed an uneven temporal pattern. There were no significant differences in the temporal abundances for buff-tailed bumble bees (Bombus terrestris), rat- tailed hover flies (Eristalis, Helophilus spp.), March flies (Dilophis nigrostigma), flower longhorn beetles (Zorion guttigerum) or the native bees (Leioproctus and Lasioglossum spp.) although, in some cases, low numbers may have masked potential unevenness trends. Variation in diurnal flower-visitation patterns among insects suggests the potential for complementarity between different pollinators.


2021 ◽  
Author(s):  
Jurene E Kemp ◽  
Francismeire J Telles ◽  
Mario Vallejo-Marin

Many plant species have floral morphologies that restrict access to floral resources, such as pollen or nectar, and only a subset of floral visitors can perform the complex handling behaviours required to extract restricted resources. Due to the time and energy required to extract resources from morphologically complex flowers, these plant species potentially compete for pollinators with co-flowering plants that have more easily accessible resources. A widespread floral mechanism restricting access to pollen is the presence of tubular anthers that open through small pores or slits (poricidal anthers). Some bees have evolved the capacity to remove pollen from poricidal anthers using vibrations, giving rise to the phenomenon of buzz-pollination. These bee vibrations that are produced for pollen extraction are presumably energetically costly, and to date, few studies have investigated whether buzz-pollinated flowers may be at a disadvantage when competing for pollinators' attention with plant species that present unrestricted pollen resources. Here, we studied Cyanella hyacinthoides (Tecophilaeaceae), a geophyte with poricidal anthers in the hyperdiverse Cape Floristic Region of South Africa, to assess how the composition and relative abundance of flowers with easily accessible pollen affect bee visitation to a buzz-pollinated plant. We found that the number of pollinator species was not influenced by community composition. However, visitation rates to C. hyacinthoides were negatively related to the abundance of flowers with more accessible resources. Visitation rates were strongly associated with petal colour, showing that flower colour is important in mediating these interactions. We conclude that buzz-pollinated plants might be at a competitive disadvantage when many easily accessible pollen sources are available, particularly when competitor species share its floral signals.


Author(s):  
José E Romero-González ◽  
Cwyn Solvi ◽  
Lars Chittka

AbstractBees efficiently learn asocial and social cues to optimise foraging from fluctuating floral resources. However, it remains unclear how bees respond to divergent sources of social information, and whether such social cues might modify bees’ natural preferences for non-social cues (e.g. flower colour), hence affecting foraging decisions. Here, we investigated honeybees’ (Apis mellifera) inspection and choices of unfamiliar flowers based on both natural colour preferences and simultaneous foraging information from conspecifics and heterospecifics. Individual honeybees’ preferences for flowers were recorded when the reward levels of a learned flower type had declined and novel-coloured flowers were available where they would find either no social information or one conspecific and one heterospecific (Bombus terrestris), each foraging from a different coloured flower (magenta or yellow). Honeybees showed a natural preference for magenta flowers. Honeybees modified their inspection of both types of flowers in response to conspecific and heterospecific social information. The presence of either demonstrator on the less-preferred yellow flower increased honeybees’ inspection of yellow flowers. Conspecific social information influenced observers’ foraging choices of yellow flowers, thus outweighing their original preference for magenta flowers. This effect was not elicited by heterospecific social information. Our results indicate that flower colour preferences of honeybees are rapidly adjusted in response to conspecific social information, which in turn is preferred over heterospecific information, possibly favouring the transmission of adaptive foraging information within species.


2011 ◽  
Vol 71 (2) ◽  
pp. 359-364 ◽  
Author(s):  
LC Rocha-Filho ◽  
IMP Rinaldi

Although crab spiders are common in flowering plants, their relations with plant species and its floral traits have been poorly known in the Neotropics. Observations regarding plant habits, floral visitors and also floral characteristics such as anthesis, odour, shape, colour and floral resources were recorded in flowering plant species of an area of "Cerrado" on a 2 km long trail. Misumenops argenteus and Misumenops pallens accounted for 62.86% of the spiders captured on 22 flowering plant species. The plants Senna rugosa (Fabaceae), Styrax ferrugineus (Styracaceae) and Banisteriopsis campestris (Malpighiaceae), hosted, each one, about 10 to 17% of the total spiders collected and these plants had diurnal anthesis, bee-attractive flower colours such as yellow (S. rugosa), white (S. ferrugineus), and pink (B. campestris), poricidal anthers as well as being visited by bees which evidenced bee-pollination syndrome. This study is the first survey regarding crab spiders and their associations with plant species of the "Cerrado".


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