Entomophilous Pollination Research Articles

Insects in Relation to Pollination of some Umbellifers

Plants and animals constitute the biotic component of every ecosystem. They interact with each other in many ways. Some interactions are synergistic and others antagonistic. But for one the survival of the other group and that of the ecosystem itself gets threatened. One of the arees of interaction between plants and animals is the pollination biology. The entomophilous pollination involves interaction between flowering plants and certain groups of insects. Entomophily has specific requirements, the entomophilous flowers are large, colourful, scented and zygomorphic. All these characteristics draw insects towards flowers and in the process pollination is effected.

Heritability of floral traits in Allium cepa L. populations from biparental crosses

AbstractOnions (Allium cepa L.) are one of the main vegetable crops worldwide. As an allogamous species with entomophilous pollination, floral traits play a critical role in seed production. Improving seed yield, especially for hybrid seed production, is very important. In this work, we obtained genetic information for floral traits using segregating populations from three male‐sterile lines and one open‐pollinated variety. Data on 16 floral traits, including perianth, gynoecium, stamens, and receptacle structures, were collected from the parental cultivars, their hybrids, and from segregating populations in the F2 and F3 generations. This dataset underpinned a comprehensive analysis of genetic variability, broad‐ and narrow‐sense heritability estimation, genetic gain predictions, and trait correlations. The evaluated traits exhibited high broad‐sense heritability values (0.08–0.85), but moderate narrow‐sense heritability values (0.01–0.68), implying that the observed phenotypic variance is mainly explained by genetic factors, with a minor additive genetic factors contribution. Consequently, the study revealed effective genetic gain for the analyzed traits. The phenotypic correlations observed in the parental cultivars were not always maintained in the segregating populations, suggesting random correlations. Meanwhile, genetic correlations were moderate to low, suggesting that the analyzed traits can be independently selected without affecting the expression of other floral traits. Notably, correlations among floral traits were significant in stable cultivars but weak in segregating populations, excluding pleiotropic effects. This work has successfully demonstrated the heritability of onion floral traits and provided a sound basis for selecting individuals with desirable attributes, with valuable practical implications for onion breeding and seed production.

Use of pollen assemblages as forensic evidence in non-seasonal high-altitude soils

Forensic palynology is a tool in criminalistics that uses spores and pollen grains to link a certain geographical location with a crime scene. The comparison of the pollen assemblage of a crime-scene soil and that of footwear of suspects and victims proved to be very useful as judicial evidence in multiple environments with marked seasonality. However, its usefulness in non-seasonal high-altitude soils has not been experimentally evaluated to the same extent. For this reason, the present study addressed this information gap by undertaking a palynological study in areas with high crime rates in the city of La Paz, Bolivia. To do this, we carried out multiple experimental samplings in three locations with different types of soil and different degrees of urbanization. Specifically, we compared whether the vegetation present at the time of taking the reference samples, was reflected in the pollen rain. Results showed that the vast majority of the species present in the vegetation were found in the pollen rain, with the exception of some plant species with entomophilous pollination syndrome. We also show that the transfer between assemblages from pollen rain to footwear happened effectively, which helped identify their geographical origin, and unveiled a great number of useful indicator species.

Relationship between pollination syndromes, pollen morphology and plant ecology in Quaternary deposits of the Cerrado

This study presents morphological descriptions and ecological information for 58 terrestrial pollen taxa and seven water-related pollen taxa from the Brazilian Cerrado, obtained from two sediment cores, Lake Feia (LFB1) and Getulio Swamp (VGE-17), encompassing the last 5000 and 15,000 cal yr BP, respectively. The relationships between the ecological and morphological traits (pollination syndrome, vegetation stratum and grain size) within each of the two depositional environments were investigated. In the LFB1 core, the pollen assemblages were dominated by arboreal pollen from closed physiognomies and lower storey trees (<10 m in height), while a combination of closed and open physiognomies was observed in the pollen assemblages from the VGE-17 core. The vast majority of the pollen taxa exhibited the entomophilous pollination syndrome, and a higher influx of entomophilous pollen was observed in both cores. Anemophilous and anemophilous/entomophilous syndromes were less well represented. Small and medium pollen grain classes were the most abundant, while the large pollen grain class was rare. The influx of small pollen grains was slightly more abundant in the lake record, while in the swamp record medium pollen grains were more abundant. Our results show that swamps and lakes differ in their representation of local versus regional pollen and in their sensitivity and responses to water-level changes. Landscape physiognomy also influences pollen dispersion: a closed physiognomy increases the local pollen signal, while a more open physiognomy results in better representation of local and regional signals.

Reproductive Biology and Breeding Systems of Two Opisthopappus Endemic and Endangered Species on the Taihang Mountains.

Opisthopappus is a perennial, endemic herb of the Taihang Mountains in China. Two species of this genus (O. longilobus and O. taihangensis) are important wild genetic resources for Asteraceae; however, their reproductive biology has been lacking until now. This study is the first detailed report on the reproductive biology and breeding systems of two Opisthopappus species. Through field observations, the floral syndromes of O. longilobus and O. taihangensis were found to possess a similar pattern, although O. taihangensis has a relatively larger capitulum, more ray ligules, and disc florets. The flowers of both O. longilobus and O. taihangensis are protandrous, a character that can prevent autogamy at the single-flower level, and insects are required for pollination. Further, brightly ligules, brightly bisexual florets, unique fragrance, and amount of nectar suggest that these species propagate via an entomophilous pollination system. Hymenopteran and Diptera species were observed as the effective pollinators for these two species. The outcrossing index, pollen/ovule ratio and the results of hand pollination indicated that these Opisthopappus species might have a mixed mating system that combines cross-fertilization and partial self-fertilization for O. longilobus and O. taihangensis, outcrossing predominated in the breeding system, while self-pollination played an important role in seed production when insect pollination was unavailable, particularly in a harsh environment, such as the Taihang Mountains cliffs. Meanwhile, O. taihangensis might better adapt to severe surroundings with relatively complex floral syndromes, specifically through the attraction of visiting insects and a high seed set rate. The above results not only provide reference information toward a better understanding of the survival strategies of O. longilobus and O. taihangensis in the Taihang Mountains but also lay a solid foundation for further exploring the molecular mechanisms that underly their adaptation under cliff environments.

Economic assessment of entomophilous pollination in crops from Argentina: possible effects of the pollinator crisis in agriculture

In Argentina, food production is the basis of economic and social development. Several crops depend on entomophilous pollination. However, wild and managed pollinators are threatened by conventional agricultural management practices. In this work, we evaluate the economic value attributed to entomophilous pollination (EEV) of the main crops between 2013 and 2018. Our study focused on analyses of crops with varying degrees of pollinator dependence in terms, their harvested area, yield and total economic value (EV). The EEV attributed to pollinators and the vulnerability of each crop category were estimated. The EEV attributed exclusively to entomophilous pollination, in the 27 crops analyzed, was US$ 4.437 million, representing a contribution of the pollinators of 21,83% of the EV and 13,8 million tons of agricultural products. The EEV in decreasing order is industrial crops, fruit trees, vegetables, nuts and citrus. In industrial crops, where managed pollinators are not used, the contribution of pollinators was high, reaching US$3.655 million. Fruit trees and vegetables are the most vulnerable to an eventual decrease or absence of pollinators with estimated vulnerability rates of 68 and 38% respectively. These results show the economic contribution of the pollinators to the country's agriculture, the high vulnerability of agroecosystems and the effects in quantitative terms of a potential reduction in food production due to a pollination deficit. Finally, this work may be useful to guide decision-making and establish public policies aimed at promoting diversification and sustainability of agricultural models to guarantee food security.

Biological Flora of Britain and Ireland: Liparis loeselii

Abstract This account presents information on all aspects of the biology of Liparis loeselii (L.) Rich. (Fen Orchid) that are relevant to understanding its ecological characteristics and behaviour. The main topics are presented within the standard framework of the Biological Flora of Britain and Ireland: distribution, habitat, communities, responses to biotic factors, responses to environment, structure and physiology, phenology, floral and seed characters, herbivores and disease, and history and conservation. Liparis loeselii is a small terrestrial orchid that has a circumboreal distribution and is widespread in Europe and North America. Despite its wide distribution, the species is locally rare and has declined considerably in most of its range. In Britain, the species has a disjunct distribution and is now known to occur consistently at only six sites in eastern England and three in south Wales. It is absent from Ireland. Its most characteristic habitats in Britain are inland fens and coastal dune slacks, but outside Britain it can also be found in wet meadows, marshes, forested seep springs, at lake borders or on mats of floating peat. Populations of Liparis loeselii in dune slacks tend to be short‐lived, and can rapidly increase in size or decrease and disappear as environmental conditions change. The species does not tolerate high nutrient concentrations or low pH. It is susceptible to drought, which reduces seed germination, seedling recruitment and adult survival. Heavy predation by rabbits and rodents has been observed under drought conditions. Liparis loeselii reproduces both by sexual reproduction, and by vegetative propagation through the production of pseudobulbs. Although flowers are accessible to insects, entomophilous pollination is unusual, and most sexual reproduction is the result of selfing. Fruits ripen late in the growing season (mid‐October) and the dust‐like seeds are dispersed during winter by wind and water. Germination occurs during the following growing season and is supported by a wide variety of mycorrhizal fungi. Since the late 19th century Liparis loeselii has declined considerably in Britain and elsewhere in Europe, primarily due to habitat destruction and loss, natural succession, and habitat desiccation due to drainage. As a result, the species has been listed as endangered in the Bern Convention and the European Habitat Directive (92/43/EEC) and is the focus of intensive conservation efforts in many countries. Restoration of habitat by mowing, extensive grazing and peat removal, and the creation of new habitat by dune slack formation in dune systems and peat removal in fens may prolong population persistence and promote establishment of new populations.

Osmophore patterns in Ipomoea asarifolia (Desr.) Roem. &amp; Schult. (Convolvulaceae)

To achieve reproductive fitness, floral attractants are essential for insect-plant interaction. Many entomophilous pollination plants have odorous zones, composed of glands that release volatile odors, these odors act as attractants for potential pollinators. Ipomea Asalifoila flowers were used for this study. One of its main characteristics is its infundibuliform morphology and glabrous leaves, and its reproductive structures are located in the center of the flower. In order to better understand the dynamics of the release of these odors, Ipomea A. flowers were collected to perform the test in neutral red 60%, and photographed before, during and after the procedure. These flowers were enveloped and separated by day of anthesis, from the first to the third day, where floral death occurred. After the tests, variations in the days of anthesis of the flowers were observed, with a gradual effect. Besides an osmotic concentration in their reproductive organs.

Incidencia de agentes polinizadores sobre la fecundación de la flor del cacao (Theobroma cacao L.)

Cocoa (Theobroma cacao L.) is a crop of economic importance distributed in 50 countries. It has great connotation in the international market and the chocolate industry. Its productivity in the field is limited by biotic and abiotic conditions; the same onesthat affect the fertilization of the flower. For this reason, the objective of this documentary research work is to know the incidence of more efficient pollinating agents on the fertilization of the cocoa flower. The bibliographic review was based on collecting information from primary sources that expose results of studies on entomophilous pollination of cocoa crop flowers, giving greater importance to research carried out in Ecuador. Emphasis was placed on the biotic factors of the agro-system of cocoa cultivation, such as the tree species that favor the habitat of the different pollinating agents; among the abiotic factorsarewind, water, temperature, humidity and soil. In the consulted literature, it was found that the most relevant benefits of the presence of pollinators in the cocoa crop are the increase in fertilized flowers and therefore the production of cobs.It is concluded that the interaction of the different populations of pollinating agents with biotic and abiotic factors within the crop ecosystem favors cocoa production. Therefore,it is advisable to use good techniques in the management of the plantation to guarantee the presence of pollinators.

Enhancing pollination ecosystem service in urban green areas: An opportunity for the conservation of pollinators

The rapid growing urbanization is one of the main threats to urban biodiversity and the ecosystem services (ES) that they provide. Pollination is one of the most affected ES in urban areas mainly due to the decline in urban green areas (UGAs) and other factors derived from urbanization itself. Considering this and the already existing global pollinator crisis, the aim of this work is the evaluation of urban green infrastructure as an opportunity for pollinator conservation. For that purpose, the ornamental vegetation of a medium-sized Mediterranean city (Granada, south-eastern Spain) was determined. The floral origin, phenology and floral traits of the conforming species and the pollinator species that they attract were analysed. Additionally, NMDS analysis were performed in order to determine if the “Pollination Syndromes” are a useful tool to actually predict the pollinator group attracted to a certain plant species. It was found that UGAs have huge potential for pollinator conservation as the major part of its ornamental species have an entomophilic pollination strategy. However, there is an imbalance in the availability of flower resources throughout the year. Hence, the addition of species flowering out of the main flowering season would be advisable in order to get a continuous supply of floral resources for pollinators. A current disproportion in the potentially attracted pollinator groups was also found out, being bees the predominantly attracted ones. However, results showed that the “Pollination Syndromes” are a tool with limitations at the moment and needs to be used with considerations. Thus, the specific plant-pollinator relationship should be determined through field work in each case-study. Further studies considering key factors such as urban connectivity and fragmentation would be desirable to ensure a comprehensive management for urban pollinators.

Current status and economic value of insect-pollinated dependent crops in Latin America

Latin America (LA) plays an important role in the global food supply and dedicates a significant part of its surface to croplands. Current losses of wild and managed pollinators are a threat to agricultural production because the productivity of many crops depends on entomophilous pollination; thus, consequences could be significant for the development of regional economies. We assess the current importance of pollination service for the main crops of Argentina, Brazil, Chile, Mexico, and Uruguay, which represent approximately 74% of the total surface of LA. Our study focused on three aspects, i) analyses of crops with varying degrees of pollinator dependence in terms of the harvested area and its yield, ii) estimation of economic value attributed to pollinators (EEV) and the vulnerability of each crop category, iii) characterization of the pollinator services provided by managed bees. Regional-level analyses showed that 58% of crops have essential and high dependence levels on insect pollination. LA produced 228.1 million tons of food that can be attributed directly to insect pollination, and an additional 33.9 million tons corresponds to crops that are not directly used for human food. The total production economic value of all crops dependent on pollination was US$ 77.82 billion, of which the economic value attributable to insect pollination was US$ 22.95 billion. Industrial crops and fruits were the leading crop category in the value of entomophilous pollination, followed by beverages, vegetables, hybrid seeds, citrus, and nuts. Crops occupy an area of 64.8 million hectares, 80% of which is used for soybean production, a clear sign of poor agricultural diversification, with Chile and Mexico being the countries with the highest degree of diversification. We estimated that hybrid seeds, fruits, and beverages whose productivity reached 44 million tons, are the most vulnerable to pollinator decline with 90, 64, and 44% vulnerability ratios. Our valuation demonstrates the vulnerability of agrosystems production, socioeconomic, and ecological terms.

Reproductive biology of an endangered lithophytic shrub and implications for its conservation

BackgroundPlants in cliff habitats may evolve specific reproductive strategies to cope with harsh environments, and unraveling these reproductive characteristics can improve our understanding of survival strategies and lithophyte evolution. This understanding is especially important for efforts to protect rare and endemic plants. Here, we investigated the reproductive biology of Lonicera oblata, an endangered lithophytic shrub that is scattered in highly fragmented and isolated cliff habitats of the Taihang and Yan mountains in North China.ResultsFlowers of L. oblata are herkogamous and protandrous, characteristics that can prevent autogamy at the single-flower level, and insects are necessary for pollination. The outcrossing index, pollen/ovule ratio, and the results of hand pollination were measured and all revealed a mixed mating system for L. oblata, that combines cross-fertilization and partial self-fertilization. The floral traits of L. oblata of zygomorphic and brightly yellowish corolla, heavy fragrance, and rich nectar, suggest an entomophilous pollination system. Sweat bees were observed as the most effective pollinators but their visiting frequencies were not high. Pollen limitation may limit the reproductive success of L. oblata.ConclusionsWe determined the reproductive characteristics of L. oblata, a critically endangered species endemic to cliffs in North China, providing insight into its endangerment and suggesting conservation strategies. L. oblata has highly pollinator-dependent self-fertilization as part of a mixed mating system. Floral features such as low-flowering synchrony, asynchronous anthers dehiscence, and high duration of stigma receptivity, improve pollination efficiency in the case of low pollinator service. Our work provides reference information to understand the survival strategies and conservation of L. oblata and other lithophytes.

Pollinators and seed dispersers of espinheira-santa (Monteverdia ilicifolia - Celastraceae), a Brazilian medicinal plant

Espinheira-santa (Monteverdia ilicifolia) is a native plant of Brazil widely used in folk medicine because it has several therapeutic properties. Regarding the pollination biology and seed dispersal of this species, there is no information available in the literature. In this study, pollinators and dispersers of M. ilicifolia were observed and identified, as well as the behavior of these biological agents during the period of flowering and fruiting. In addition, the frequency of pollinator visits and the efficiency of the seed disperser were recorded. It was verified that in espinheira-santa, pollination is carried out by diptera and by hymenoptera. Among the main groups of pollinators are the flies, being Lucilia eximia, Limnophora sp. and Eristalis sp. the most frequent, and the wasps, in which Brachygastra mellifica, Polistes canadensis, Mischocyttarus sp. and one species of the Tiphiidae family were the most frequent. Eight species of birds consumed diaspores (arils with seeds), acting as dispersers of this species. However, the following birds were more efficient in the dispersion of seeds: Tangara sayaca, Elaenia sp. and Pipraeidea bonariensis. In this sense, M. ilicifolia is a species that has entomophilous pollination and ornithochoric dispersion.

Unusual underwater flowering of Utricularia australis populations: a botanical enigma?

The free-floating aquatic plant Utricularia australis has typically subsurface shoots and subaerial showy inflorescences. To find it growing with large populations among benthic Chara stands at 4–6 m depth in two Central Italian lakes, is a phenomenon that was never previously reported. Production of showy chasmogamous flowers at this depth makes such finding yet increasingly intriguing. Here we make quantitative-qualitative comparisons of morphological characters among subaerial and underwater flowers taken from diverse sites in Central Italy. Environmental data were used to delineate differences between superficial and underwater habitats where flowering U. australis populations were found, and to help explain these extraordinary findings. Although similar, the subaerial and underwater flowers did show some differences, the most important being the length of the floral scape. Underwater scapes were around three times longer than those emerged. This might be a typical phototropic-response or a failed attempt to get flowers above water surface for allowing entomophilous pollination, or a redundant morpho-physiological trait as a result of a recent ecological move. Underwater flowers were generally smaller, but they did have longer styles, nectar signalling was less obvious, thinner petals, mucous-coated pollen (subaerial pollen is dry and grainy). Both types of flower were sterile, producing abortive fruits. Possibility of underwater ecological conditions causing stress-induced flowering is also proposed. A lack of water movement is an important ecological requirement for U. australis growth and could explain why large populations have been found in deep water far from its typical habitat.

Dependence of soybeans (Glycine Max Merril) to entomophile pollination and study of food resources of honey bees (Apis Mellifera L.) in contact with the crop

South America suffered strong modifications during the last decade due to the increase in anthropic activities and the expansion of agricultural areas, particularly soybeans, interacting with traditional productions such as Beekeeping. The objective of this research was to know the dependence of two soybean varieties on entomophilic pollination by means of meshing and to reveal the diversity of insects in contact with the crop, especially determining the interaction of the honeybee with it. In addition, a sample of bees was carried out in different areas of the country to compare the diversity of species between areas with anthropic management during 2015–2016 and 2016–2017. Specimens were collected and classified according to taxonomic keys. The main results: 1- Forty-five species of bees or taxa belonging to the subfamilies Megachilinae (11), Apinae (22), Halictinae (7), Colletinae (2) and Andreninae (3) were distinguished in the southern region of Uruguay and 6 of them were in contact with the crop. 2- The diversity of bees was greater for the southern region, with traditional agriculture and pastures, than that of the low-lying coastal region where an increasing use of agricultural land took place during the last decade, especially soybeans. 3 - At least two species of native bees use soy as a plant resource to make their nests. 4- Honey bees use soybeans as a source of pollen and nectar, but the flowers on the edge of the crop provide pollen and nectar that compete with soybeans. 5- Soy shows a different degree of dependence on insects to form seeds related to the amount of exchangeable K in the soil. 6- The edges of the crop are important to provide food and shelter for pollinators. This study addresses the interaction between soybeans, native bees and honeybees, showing the points of contact between them. In addition, complementary data are obtained on biotic and nutrient agents that intervene in the flowering of Soybeans, helping to think about strategies for coexistence of items.

Comparative Efficiency of Native Insect Pollinators in Reproductive Performance of Medicago sativa L. in Pakistan

Simple SummaryLucerne (Medicago sativa L.) is a cross-pollinated crop and pollination does not usually take place until the sexual column is released. The discharge of the sexual column is referred to as ‘tripping’ the flower. In this study, several bee species were investigated to facilitate the pollination of lucerne crop with a purpose to examine the pollination efficiencies of native insect pollinators that lead to a seed set of alfalfa. We designed a two-year field trial to investigate the abundance and diversity of insect pollinators along with foraging behavior in terms of stay time, visitation rate, pollen harvest and tripping efficiency. Moreover, the single-visit efficiency in terms of number of seeds per pod, germination and seed yield was evaluated. Ten major pollinators (five solitary bees, three honeybees and two flies) were tested for their pollination efficiency as effective pollinators. Findings show the solitary bees (Megachile cephalotes, Megachile hera, Amegilla sp.) can be recommended as an effective pollinator for this crop, thus increasing options available to seed growers. For lucerne seed development, more consideration should be paid to the variety of native wild bees, conservation strategies and foraging requirements in establishing a diverse pollination system rather than a single bee species.Lucerne (Medicago sativa L.) is a cross-pollinated crop and requires entomophilous pollination for tripping of flowers and subsequent pod and seed set. To discover the best pollinators for lucerne seed production, a two-year field trial was carried out at the research farm of MNS University of Agriculture, Multan, Pakistan. Abundance and diversity of insect pollinators along with the foraging behavior were recorded in terms of tripping efficiency, stay time, visitation rate and pollen harvest. The single-visit efficiency of abundant insect pollinators was also evaluated in terms of number of seeds and seed weight per raceme along with germination percentage. Ten most abundant floral visitors (five solitary bee species, three honeybee species and two syrphid fly species) were tested for their pollination efficiency. Honeybees were most abundant in both the years followed by the solitary bees and syrphid flies. Single-visit efficacy in terms of number of pods per raceme, number of seeds per raceme, 1000 seed weight and germination percentage revealed Megachile cephalotes as the most efficient insect pollinator followed by Megachile hera and Amegilla sp. Future studies should investigate the biology and ecology of these bee species with special emphasis on their nesting behavior and seasonality.

Floral attraction and flower visitors of a subcanopy, tropical rainforest tree, Fontainea picrosperma.

Flowering plants in tropical rainforests rely heavily on pollen vectors for successful reproduction. Research into pollination systems in tropical rainforests is dominated by canopy species, while subcanopy plant–pollinator interactions remain under‐represented. The microclimate beneath the rainforest canopy is characterized by low light levels and is markedly different from the canopy environment that receives more light energy.We studied the floral attractants and floral visitors of a dioecious, subcanopy tree, Fontainea picrosperma (Euphorbiaceae), in the Wet Tropics bioregion of northern Queensland, Australia.We found that wind pollination is rare and male and female flowers do not produce nectar. Female flowers are likely pollinated due to their perceptual similarity to pollen‐offering male flowers. Female flowers had the same scent profile as male flowers, and floral scent was an important floral attractant that acted to regulate pollinator behavior. The two most abundant scent compounds present in the floral bouquet were benzyl alcohol and 4‐oxoisophorone. These compounds are ubiquitous in nature and are known to attract a wide variety of insects. Both day‐time and night‐time pollinators contributed to successful pollen deposition on the stigma, and diurnal flower visitors were identified from several orders of insects including beetles, flies, predatory wasps, and thrips. Fontainea picrosperma is therefore likely to be pollinated by a diverse array of small insects.Synthesis. Our data indicate that F. picrosperma has a generalist, entomophilous pollination syndrome. The rainforest subcanopy is a distinctive environment characterized by low light levels, low or turbulent wind speeds, and relatively high humidity. Female flowers of F. picrosperma exhibit cost‐saving strategies by not producing nectar and mimicking the smell of reward‐offering male flowers. Insects opportunistically forage on or inhabit flowers, and pollination occurs from a pool of small insects with low energy requirements that are found beneath the rainforest canopy.

Complementary Contribution of Wild Bumblebees and Managed Honeybee to the Pollination Niche of an Introduced Blueberry Crop.

Simple SummaryBlueberry is a crop that is increasing globally, both in terms of yield and extent, mostly thanks to the recent introduction of North American blueberry in the temperate areas of Europe, Asia, and South America. As blueberry depends largely on insects for pollination, farmers in these expansion areas face the challenge of adapting this crop to unexpected pollinator species, whose traits and features may not entirely fit the pollination needs of the introduced crop. Here we study the abundance, the behaviour, and the response to environmental conditions of different managed and wild native pollinators of blueberry in northern Spain. Our findings suggest the dominant role of native wild bumblebees and managed honeybee as suppliers of pollination service. Honeybee and bumblebees differed in both when and where they occurred, in how they responded to environmental conditions, and in how they behaved as an effective pollinator. The role of bumblebees and honeybee as blueberry pollinators thus seems complementary and additive. These results encourage the preservation of populations of native wild bees in order to ensure the effective management of introduced blueberry crops.The entomophilous pollination niche (abundance, phenotypic traits, foraging behaviours and environmental tolerances of insect pollinators) helps to understand and better manage crop pollination. We apply this niche approach to assess how an entomophilous crop (blueberry, Vaccinium ashei) can be expanded into new territories (i.e., northern Spain) far from their original area of domestication (North America). Insect visits to blueberry flowers were monitored in a plantation on 12 different days, at 8 different times during day and covering various weather conditions. Abundance, visitation rate, pollen gathering behaviour, and frequency of inter-plant and inter-row movements were recorded. The pollinator assemblage was basically composed of one managed honeybee species (50.8% of visits) and three native bumblebee species (48.3%). There was a marked pattern of seasonal segregation throughout bloom, with bumblebees dominating the early bloom and honeybee the late bloom. Pollinators also segregated along gradients of daily temperature and relative humidity. Finally, the two pollinator types differed in foraging behaviour, with bumblebees having a visitation rate double that of honeybee, collecting pollen more frequently and changing plant and row more frequently. The spatio-temporal and functional complementarity between honeybee and bumblebees suggested here encourages the consideration of an integrated crop pollination strategy for blueberries, based on the concurrence of both wild and managed bees.

Preferencias florales por abejas Meliponas beecheii en diferentes variedades de Cucurbita moschata. L

The objective of the research was, through a completely randomized experimental design, to determine the variety of Cucurbita moschata L. preferred by bees during the pollination process. In November 2018, four varieties of pumpkins were planted. After the flowering started, sampling was started. Five morning samplings were carried out from January 31 to February 28, 2019. In each sampling, two observations were made separated in time. The open flowers in each variety and the number of bees present were recorded. Meliponas bees had a lower preference for the Fifi variety and a higher preference for the INIVIT C-2000 variety. There were no differences between observation times regarding the number of open flowers between varieties. During the entire investigation, bees were observed within the field. Melipon Bees were found mostly during the first observation. There was a correlation between the total number of bees observed per variety and the yields, demonstrating the importance of entomophilic pollination.

Chrysophyllum marginatum (Sapotaceae): Generalist pollination and cryptic gynomonoecious

AbstractChrysophyllum (Chrysophylloideae, Chrysophylleae) is the second largest genus in the Sapotaceae. Studies of pollination ecology in this genus are non‐existent, although there are records of entomophily for this family. Considering the lack of detailed studies on pollination ecology and sexual systems in Chrysophyllum species, we investigate the floral morphology and biology and floral visitors of Chrysophyllum marginatum to verify which sexual system is present in the studied population and whether flowers of this species are visited and pollinated by different insect groups. The population of C. marginatum has weak and cryptic gynomonoecy because the plants produce a low percentage of functionally pistillate flowers (4.2%) and these flowers appear to be perfect flowers (hermaphrode). Flowers of C. marginatum are phenotypically, ecologically and functionally generalist because: (a) they are actinomorphic, open and not restrictive in terms of access to floral resources; (b) they are visited by 26 species of insects that are potential pollinators; and (c) among these species several groups can be effective pollinators, mainly bees and flies, according to the most effective pollinator principle. We consider bees and flies to be the main pollinator group of C. marginatum, due to their high visitation rate, richness and intrafloral visiting behavior, and because they especially forage among plant individuals and are able to promote xenogamy. Nectaries were found in the ovary base and osmophores in the petal margins, as floral attractants. For Chrysophyllum, this is the first record of gynomonoecy and for the family this is considered the second record. Chrysophyllum marginatum has generalist and entomophilous pollination, as recorded in other Sapotaceae Neotropical species.