Pollination biology

In the neotropics, central Mexico and Venezuela, columnar cacti (mostly belonging to tribe Pachycereae) are pollinated mainly by bats. In the Tehuacán Valley 36 species of columnar cacti have their blooming peak almost simultaneously between April and June, and species with chiropterophilous pollination have been shown to be self-incompatible, fruiting only after bat pollination. Nectarivorous bats are abundant also during spring and summer, and migrate during autumn and winter. Two columnar cacti, Pachycereus weberi (tribe Pachycereae) and Pilosocereus chrysacanthus (tribe Cereae), flower during winter and early spring facing an apparent scarcity of bats. We hypothesized that under this condition, these plants may resemble the columnar cacti in extratropical deserts where both bats and diurnal vectors can effect seed production. However, we found that these two plant species have white, long tubular flowers, are nocturnal, self-incompatible and produce fruits only after the visitation of four nectar-feeding bats and two frugivorous bats. We found that nectar-feeding bats have a small resident population in the Valley. In addition these cacti species grow along possible routes of bat altitudinal migration. A long, and possibly variable flowering season may be also related to low pollen vector density.

The capacity for cone-mediated color vision varies among nocturnal primates. Some species are col- orblind, having lost the functionality of their short-wavelength-sensitive-1 (SWS1) opsin pigment gene. In other species, such as the aye-aye (Daubentonia madagascariensis), the SWS1 gene re- mains intact. Recent studies focused on aye-ayes indicate that this gene has been maintained by natural selection and that the pigment has a peak sensitivity (λmax) of 406 nm, which is ∼20 nm closer to the ultraviolet region of the spectrum than in most primates. The functional significance behind the retention and unusual λmax of this opsin pigment is unknown, and it is perplexing given that all mammals are presumed to be colorblind in the dark. Here we comment on this puzzle and discuss recent findings on the color vision intensity thresholds of terrestrial vertebrates with com- parable optics to aye-ayes. We draw attention to the twilight activities of aye-ayes and report that twilight is enriched in short-wavelength (bluish) light. We also show that the intensity of twilight and full moonlight is probably sufficient to support cone-mediated color vision. We speculate that the intact SWS1 opsin pigment gene of aye-ayes is a crepuscular adaptation and we report on the blueness of potential visual targets, such as scent marks and the brilliant blue arils of Ravenala madagascariensis.

We studied the diet of the Indian flying fox (Pteropus giganteus) in Pakistan from March 2008 to February 2009 and found that
the bats fed on 20 species belonging to 11 plant families. Of these, four families (Anacardiaceae, Bignonaceae, Malvaceae, and
Sapotaceae) were identified from remnants of flower petals in food boluses while the remaining families (Annonaceae, Arecaceae, Ebenaceae, Meliaceae, Moraceae, Myrtaceae, and Sapindaceae) were identified from the seeds in the boluses and from guano samples. Plants in the family Moraceae (50.7%) comprised most of the bat’s diet. Fruit of Ficus retusa (27.5%) and F. carica (23.0%) during winter, F. glomerata (30.9%) and F. religiosa (28.1%) during spring, Psidium guajava (19.6%), F. bengalensis (18.7%) and Diospyros peregrina (17.8%) during summer, and D. peregrina (71.9%) during autumn, were the most frequently identified items. The four seasonal diets varied significantly (χ2 = 435, d.f. = 18, P < 0.01). Results confirm that the ecological services rendered by P. giganteus, such as pollination and seed dispersal, outweigh its losses, such as damage to the ripe fruit. Hence, the species should not be regarded as a pest; rather efforts should be made to ensure its conservation.

Various aspects of the pollination biology of the alpine flora of Kosciusko National Park, NSW, were examined from late December 1983 until the end of March 1984, including flowering phenology, corolla tube lengths, flower colour, ultraviolet reflectance patterns, visitation rates to the flowers and proboscis lengths of the flower-visiting insects. An average of 5.3 species flowered in each of 13, 2 m×2 m montane plots and 5.6 species in the 13 alpine plots. The maximum number in flower simultaneously averaged 4.1 species in the montane and 3.3 in the alpine plots; flowering peaked in mid-January, Corolla tube lengths of the flora averaged 1.73 mm.The most common floral colour was white or predominantly white (40 species), followed by yellow (14 species). Only six of the 38 species (16%) examined had some type of reflectance pattern; the remaining species all absobed ultraviolet.Flies appeared to be the major pollinators. The insects collected in the study area comprised 60 species of Diptera, 33 species of Hymenoptera, and several species each of Lepidoptera and Coleoptera. On average, 14.4% of flowers watched during 379 observation periods (10 min each) were visited. On average, each plant species was visited by 6.4 species of flies, 2.4 species of bees, wasps or sawflies, one species of butterfly or moth and 0.3 species of beetles. Visitation rates increased over the growing season, and were significantly affected by ambient temperature (positively), light levels (positively) and wind speed (negatively).The maximum proboscis length for the 25 most common species of bees was 2.76 mm, but 18 of 51 species of flies had proboscis lengths longer than this. The mean proboscis length for all 25 species of bees was 1.68 mm, and for 51 species of flies was 2.31 mm. Proboscis lengths for flies were positively correlated with the average corolla length for the plant species they visited. For bees, however, the range in proboscis lengths was relatively small and did not show this pattern.There appear to be significant differences between the plant-pollinator community of alpine Australia and other alpine areas where bumblebees are common pollinators. These differences include shorter proboscis and corolla tube lengths, and perhaps an increased diversity and significance of flies as pollinators.

This research was carried out to evaluate the floral biology of Ipomoea acuminata, I. batata, I. cairica and I. quamoclit in Maringá, state of Paraná. Anthesis period, stigma receptivity, viability of the pollen grains and medium height of the style and filament were analyzed during the blossom period of Ipomoea. Both I. quamoclit and I. potato had their flowers opening at 6:00 a.m. and their closing at 2:00 p.m. The test of stigma receptivity demonstrated that I. quamoclit was receptive between 6:00 a.m. and 9:00 a.m. and I. batata between 6:35 a.m. and 1:00 p.m. The period of higher viability of the pollen grains in I. quamoclit was the same of the stigma receptivity. In that species, there was a reduction in the frequency of viable grains of pollen next to the time of the flowers closing. There were highest frequencies of viable pollen grains in I. batata between 6:35 a.m. and 7:00 a.m.; the variations in the frequency of viability of the pollen grains keep along the day until the flowers closing. In I. acuminata, the medium height of the style was 27.245 ± 2.431 mm and the medium height of the filament was 26.439 ± 3.147 mm. In I. batata, the medium height of the style was 19.77 mm ± 1.956 mm that is higher than the medium height of the filament. The medium height of the style in I. cairica was 19.827 mm and the medium height of the filament was 17.952 mm. In I. quamoclit the medium height of the style and the medium height of the filament had both bigger and smaller height variations of the style. For that species the estimated differences between the medium height of the style at 8:30 a.m. and the filament 1 and 4; and between the medium height of the style at 10:30 a.m. and filament 3, 4 and 5 were significant. For I. batata the differences between the medium heights of the style and of the filament were significant.

We examined pollination biology of Acacia nigrescens Oliver, flowering at the end of the dry season in Kruger National Park, South Africa. A. nigrescens produces small quantities of concentrated nectar, and has abundant pollen resources available to potential pollinators. We recorded large numbers of insect visitors and most fruit set on the tops of trees, beyond the reach of ungulate browsers such as giraffes (which consume a substantial proportion of A. nigrescens flowers). Wasps, flies and solitary bees were the most numerous visitors and are likely to play a significant role in pollination.

The observations on flowering behavior and fruit set of the various pollinizer cultivars were compared with main
cultivar ‘Red Delicious’. Among the various pollinizers and main cultivar ‘Red Delicious’, the flower bud initiation in
the year 2002 and 2003 were started the earliest on 22nd March ( Manchurian) and 21st March (Snowdrift),
respectively and subsequent flowering remain continued till 19th April (Red Gold ) in 2002 and 21st April (Red
Delicious) in 2003. The mean bloom density varied from 39.32% (Golden Spur) to 82.35% (Snowdrift) in 2002 to
35.41% (Ty. Early Worcester) to 84.34 %( Snowdrift) in 2003. The time of peak anthesis and anther dehiscence were
observed at 11:00 hours and 14:00 hours of a day, respectively. Under all pollination methods, the crabs (Manchurian,
Snowdrift and Golden Hornet) and commercial pollinizer Summer Queen exhibited excellent fruit set to ‘Red Delicious’.
Among methods of pollination, the bouquet placement proved to be most effective in improving the fruit set to the
main cultivar ‘Red Delicious’. Therefore, all the crabs as well as commercial pollinizer Summer Queen can be
recommended for apple cv. Red Delicious as a pollinizer in improving the fruit set and subsequent yield.

Background and aims Pollination is a critical stage in plant reproduction and thus in the maintenance and evolution of species and communities. The Caatinga is the fourth largest ecosystem in Brazil, but despite its great extent and its importance few studies providing ecological information are available, with a notable lack of work focusing on pollination biology. Here, general data are presented regarding the frequency of pollination systems within Caatinga communities, with the aim of characterizing patterns related to floral attributes in order to make possible comparisons with data for plant communities in other tropical areas, and to test ideas about the utility of syndromes. This paper also intends to provide a reference point for further studies on pollination ecology in this threatened ecosystem.

Microscopy Cells are small and in almost all situations a microscope is needed to observe them and their subcellular components. In fact the invention of the microscope led to the discovery and description of cells by Hooke in 1655. The microscope is still an extremely important tool in biological research. Microscope as the name suggests are instruments that help to enlarge minute (micro = very small) organisms or their parts. A microscope not only presents a magnified view of the object but also 'resolves' it better. There are two fundamentally different types of microscope:

Systematic biology is a discipline rooted in collections. These collections play important roles in research and conservation and are integral to our efforts to educate society about biodiversity and conservation. Collections provide an invaluable record of the distribution of organisms throughout the world and through recent and geological time, and they are the only direct documentation of the biological, physical, and cultural diversity of the planet: past, present, and future. Recent developments in bioinformatics and cyberinfrastructure are transforming
systematics by opening up new opportunities and as a result major digitization efforts have increasingly made
available large amounts of biodiversity data. The collections-based systematics community needs to train the next generation of systematists with integrative skills, address grand questions about biodiversity at different scales, develop a community-wide cyberinfrastructure, effectively disseminate systematic data to biologists and the public, and proactively educate the public and policy makers on the importance of systematics and collections in the biodiversity crisis of the Anthropocene. Specifically, we call for a new global Biodiversity CyberBank, comparable to GenBank for genetic data, to be the repository of all biodiversity data, as well as a World Organization of Systematic Biology to lead major initiatives of the field. We also outline a new workflow for taxonomic monographs, which
utilizes both the traditional strengths of synthesizing diverse collections-based taxonomic data and the capacity of
online resources and bioinformatics tools.

Problem of diseases is a serious concern both in domesticated and wild soiltary bees. When disease strikes a hive of bees, it can devastate the colony and spread to the entire beekeeping operation. All bees are susceptible to diseases, and when they are domesticated, their population densities increase to suit human needs, making them more susceptible. Decline in their population has threatened the food security on global scale through deficit of pollinators. Most attempts at disease control have centered on drug treatments leading to resistance in disease causing pathogens and problem of residues in hive products. This chapter discusses how disease control strategies could be improved by breeding bees for disease resistance and better hygienic behaviour allowing researchers to identify that time and place in the management system for which the pathogen is most vulnerable, followed by targeting treatments to that stage. 605 18.2 Problem of Diseases in Honeybees ceranae has a pathology that is different from Nosema apis. The causative agent for Nosema is Nosema apis, which rarely causes major losses in infected colonies. However, high mortality rate demonstrates that N. ceranae is highly pathogenic to Apis mellifera. Bees die within 8 days after exposure to N. ceranae which is faster than bees exposed to N. apis. Some new viruses and bacteria have been discovered.

The European honey bee, Apis mellifera, is well-known for its role in honey production, its ecological importance in plant reproduction and biodiversity, and more importantly, the pollination of many economically significant crops in the United States (Staveley, Law, Fairbrother, & Menzie, 2014; vanEngelsdorp & Meixner, 2010). The food we eat from the most nutritious crops in our diets – key fruits and vegetables – as well as some crops used as fodder in meat and dairy production significantly depend on the key ecosystem service that honey bees  provide: natural insect-mediated pollination (Tirado, Simon, & Johnston, 2013). As the predominant and most economically important group of pollinators in most geographical regions, both managed and wild honey bees pollinate most wild plants so that they may reproduce, thereby directly or indirectly supporting wild habitats that provide other ecosystem services (Tirado et al., 2013). One can then see the possible ramifications of the ongoing bee colony decline in recent years; however, the economic and ecological consequences tend to be viewed separately in their own scope, and it is not entirely clear how the two areas intersect.

This paper comprises Part II of a review of flower visitation and pollination by Diptera (myiophily or myophily). While Part I examined taxonomic diversity of anthophilous flies, here we consider the rewards and attractants used by flowers to procure visits by flies, and their importance in the lives of flies. Food rewards such as pollen and nectar are the primary reasons for flower visits, but there is also a diversity of non-nutritive rewards such as brood sites, shelter, and places of congregation. Floral attractants are the visual and chemical cues used by Diptera to locate flowers and the rewards that they offer, and we show how they act to increase the probability of floral visitation. Lastly, we discuss the various ways in which flowers manipulate the behaviour of flies, deceiving them to visit flowers that do not provide the advertised reward, and how some flies illegitimately remove floral rewards without causing pollination. Our review demonstrates that myiophily is a syndrome corresponding to elements of anatomical, behavioural and physiological adaptations of flower-visiting Diptera. The bewildering diversity of anthophilous Diptera and of the floral attractants and rewards to which they respond allows for only broad generalizations on myiophily and points to the need for more investigation. Ecological relationships between flies and flowers are critical to the survival of each group in many habitats. We require greater understanding of the significance of flies in pollination, especially in the face of recent pollinator declines.

This paper comprises Part II of a review of flower visitation and pollination by Diptera (myiophily or myophily). While Part I examined taxonomic diversity of anthophilous flies, here we consider the rewards and attractants used by flowers to procure visits by flies, and their importance in the lives of flies. Food rewards such as pollen and nectar are the primary reasons for flower visits, but there is also a diversity of non-nutritive rewards such as brood sites, shelter, and places of congregation. Floral attractants are the visual and chemical cues used by Diptera to locate flowers and the rewards that they offer, and we show how they act to increase the probability of floral visitation. Lastly, we discuss the various ways in which flowers manipulate the behaviour of flies, deceiving them to visit flowers that do not provide the advertised reward, and how some flies illegitimately remove floral rewards without causing pollination. Our review demonstrates that myiophily is a syndrome corresponding to elements of anatomical, behavioural and physiological adaptations of flower-visiting Diptera. The bewildering diversity of anthophilous Diptera and of the floral attractants and rewards to which they respond allows for only broad generalizations on myiophily and points to the need for more investigation. Ecological relationships between flies and flowers are critical to the survival of each group in many habitats. We require greater understanding of the significance of flies in pollination, especially in the face of recent pollinator declines.

The focus of agriculture is slowly shifting from traditional cereal crops to high-value cash crops farming such as fruits and vegetables. This transformation from subsistence systems to commercial agriculture poses new challenges for improving and maintaining productivity and quality. Among these challenges are crop failures due to inadequate pollination. This is caused by several factors, the most important of which include the lack of adequate number of pollinators as a result of decline in pollinator populations and diversity due to several factors such as decline in wilderness and loss of habitat, land use changes, monoculture-dominated agriculture and excessive and indiscriminate use of agricultural chemicals and pesticides. Consequently, the need for ensuring pollination particularly through conserving pollinators and incorporating managed crop pollination has increased and will increase further. This calls for a more intensive focus on the issue from the perspective of policy, research, development and extension. Policy reorientation, improving institutional capabilities and human resources development are the key areas needing attention.

The focus of agriculture is slowly shifting from traditional cereal crops to high-value cash crops farming such as fruits and vegetables. This transformation from subsistence systems to commercial agriculture poses new challenges for improving and maintaining productivity and quality. Among these challenges are crop failures due to inadequate pollination. This is caused by several factors, the most important of which include the lack of adequate number of pollinators as a result of decline in pollinator populations and diversity due to several factors such as decline in wilderness and loss of habitat, land use changes, monoculture-dominated agriculture and excessive and indiscriminate use of agricultural chemicals and pesticides. Consequently, the need for ensuring pollination particularly through conserving pollinators and incorporating managed crop pollination has increased and will increase further. This calls for a more intensive focus on the issue from the perspective of policy, research, development and extension. Policy reorientation, improving institutional capabilities and human resources development are the key areas needing attention.

*Zewdie Kassa, *Zemede Asfaw and Sebsebe Demissew*
*Addis Ababa University, College of Natural Sciences, Department of Plant Biology and Biodiversity Management
ABSTRACT
A study on plant diversity and ethnobotany was conducted between  October 2013 and September 2014  in Tulu Korma and its surrounding areas of Ejere District, West Shewa Zone of Oromia Regional State, Ethiopia. The objective of the study was to document plant species diversity of the area together with the associated ethnobotanical knowledge as well as to see the status and trends of biodiversity change in biodiversity the area. The various common ecological and ethnobotanical methodologies and techniques were applied during the course of the study. About 156 informants were interviewed to retrieve ethnobotanical data. A 30m by 30m quadrate was used to sample vegetation and sub plots of 2mx2m for grasses and sedges, 5mx5m for herbs and 10mx10m for shrubs were established to estimate cover abundance values. About 304 plant species belonging to 216 genera and 78 families were recorded from the area.  From the total species, 251 were recorded from 50 quadrates and the remaining 53 species were recorded from outside the plots. R statistical Software was used to run cluster analysis and four plant community types were identified. Ordination techniques were followed to see the major environmental variables structuring the floristic composition and plant community types and altitude was found to be the most influential environmental variable at 95% confidence interval (P=0.005) for both RDA and CCA ordination. The Shannon-Weiner Diversity index was also calculated to see the overall diversity of the study area. The area is with relatively high plant species diverse at H’= 3.37 with overall species evenness, J= 0.61 confirming the fact that Shewa floristic region is among the most species rich habitats. About 12 major plant use categories were identified and value of informants’ consensus factor showed medicinal use was ranked first. The study showed that the area is rich in plant species and floristic composition, hence, experiences adopted by the Centre for Indigenous Trees Propagation and Biodiversity Development in Ethiopia located at Tulu Korma should be the lessons learned for the restoration and rehabilitation of similar environments in other areas.
Key words: Diversity, Ethnobotany, Tulu Korma, Multipurpose plants, Indigenous species

Phenology, pollination biology and breeding system were investigated in three populations of Acacia senegal located in Delhi and Rajasthan. Flowers emit a mild fragrance and produce a minute quantity of nectar. The stigma is wet non-papillate, cup-shaped and generally accommodates one polyad with 16 pollen grains. The style is solid. The mass effect created by the brush type of blossoms attracts a wide variety of insects, of which the giant Asian honeybee, Apis dorsata, is the effective pollinator. Manual in vivo pollination studies have shown that the species is self-incompatible. Self-incompatibility appears to operate inside the embryo sac. Under natural conditions fruit set is as low as 0.36%. Insufficient pollination is the main cause of low fruit set. Manual xenogamous pollinations substantially improve fruit set to 30%.

Plants use chemical components to attract potential pollinators to visit flowers and facilitate the efficient transfer of pollen The Evolution of plant volatile production in pollination ecology and in pollinator-plant relationships has been discussed in this chapter. When insects, birds and bats visit flowers for nectar and pollen,

Abstract. CLAESSENS, J. & KLEYNEN, J. - In the past many forms of Ophrys apifera were described at very different taxonomic levels. There were continuous discussions if these taxa should be considered to be forms, varieties, subspecies or even species. In order to clarify the taxonomic relevance of these forms, the authors investigated a population of various forms of O. apifera in the Eifel (Germany) over a period of six years. From the exact observations of 294 individuals it proved that 23 plants changed their forms. There were as well plants that changed from the nominate plant to friburgensis- or botteronii-forms as others that changed from friburgensis to botteronii. Those changes indicate clearly that the forms of O. apifera that were followed in the observations do not have any systematic or taxonomic relevance and therefore have to be considered as being an expression of the variability of O. apifera.

This chapter describes how the climate change is potentially the most severe threat to pollinator biodiversity. Mounting evidence demonstrates that there have already been biotic responses to the relatively small climate changes that have occurred this century. Pollinators such as birds, bees, butterflies, moths, flies, wasps, beetles bats and even mosquitoes are essential for food production because they transfer pollen between seed plants-impacting 35% of the world's crops. Along with providing an essential service to human populations, pollinators also have a key role in maintaining other ecosystem services including ensuring biodiversity and helping Nature to adjust to external threats such as climate change. The "pollination crisis" that is evident in declines of honeybees and native bees worldwide is due to disruption of critical balance between the two mutually interacting organisms. Anthropogenic climate change is widely expected to drive species extinct by hampering individual survival and reproduction, by reducing the amount and accessibility of suitable habitat, or by eliminating other organisms that are essential to the species in question. The potential disruption of a ubiquitous mutualistic interaction of terrestrial habitats, that between plants and their animal pollinators, via climate change is at risk.

During three weeks of field work in 2017, two of the authors (M. C. & J. C) searched for potential orchid sites in Gran Canaria, resulting in a large number of unknown orchid sites. These data were supplemented with samples from the LPA Herbarium and unpublished data provided by two other authors (A. M. and D. G.). Finally chorological data were complemented with field campaigns during the season 2018-2019 (A.M. and C.S.). Orchids are limited almost exclusively to the Northeastern slopes and peaks of the island; the mountain region of Tenteniguada and Vega de San Mateo, Barranco de la Virgen in Valleseco, environments of Los Tiles, in Moya and the pine trees of Tamadaba and Tirma proved to be sites rich in species and in numbers of plants. Data are presented on chorological maps of Habenaria tridactylites (which has been located in 90 UTM-km grids), Orchis patens subsp. canariensis (located in 40 UTM-km grids), Gennaria diphylla (in 21 UTM-km grids), Neotinea maculata (in 24 UTM-km grids) and Ophrys bombyliflora (located in 10 UTM-km grids), as well as maps of densities of these species. Also the presence of Serapias parviflora and Himantoglossum metlesicsianum on the island is commented.

Floral symmetry has figured prominently in the study of both pollination biology and animal behavior. However, a confusion of terminology and the diffuse nature of the literature has limited our understanding of the role that this basic characteristic of flower form has played in plant-pollinator interactions. Here, we first contribute a classification scheme for floral symmetry that we hope will resolve some of the confusion resulting from the inconsistent application of terms. Next, we present a short review of the distribution of floral forms in angiosperm families. Finally, we provide a list of hypotheses and, when available, supporting evidence for the causes of the evolution of floral symmetry. 345 0066-4162/98/1120-0345$08.00 d Although organs radiate from the principal axis, the spiral arrangement of organs results in no repetition of pattern for the flower as a whole.

The pollination biology of the orchid Ceratandra grandiflora was investigated in order to determine whether the partial loss of a specialized floral reward (i.e., oil) was the result of an incomplete shift from one specialized pollinator to another. In the three-species clade of section Ceratandra, there has been a progressive loss of the oil-secreting callus. It is always present in C. atrata, sometimes present in C. grandiflora, and never present in C. globosa. Thirty-nine to 67% of individuals in populations of C. grandiflora bear the callus gland, but gland presence has no significant effect on the proportion of flowers pollinated. Pollinator observations show that the shift in pollinators is complete and that the oil-secreting callus is a vestige of the ancestral oil-bee pollination system that no longer plays a role in pollination. C. grandiflora is pollinated almost exclusively by a single species of hopliine beetle (Scarabaeidae). Experiments with artificial flower traps indicate that color alone can explain the attraction of beetles to C. grandiflora, despite the absence of a floral reward. The proportion of C. grandiflora flowers pollinated (50.2 and 61.1%; N ϭ 524 and 324 flowers, respectively) is unusually high for a plant that relies on generalized food deception and is probably due to the use of inflorescences as mating sites (i.e., rendezvous pollination).

Problem of diseases is a serious concern both in domesticated and wild soiltary bees. When disease strikes a hive of bees, it can devastate the colony and spread to the entire beekeeping operation. All bees are susceptible to diseases, and when they are domesticated, their population densities increase to suit human needs, making them more susceptible. Decline in their population has threatened the food security on global scale through deficit of pollinators. Most attempts at disease control have centered on drug treatments leading to resistance in disease causing pathogens and problem of residues in hive products. This chapter discusses how disease control strategies could be improved by breeding bees for disease resistance and better hygienic behaviour allowing researchers to identify that time and place in the management system for which the pathogen is most vulnerable, followed by targeting treatments to that stage. 605 18.2 Problem of Diseases in Honeybees ceranae has a pathology that is different from Nosema apis. The causative agent for Nosema is Nosema apis, which rarely causes major losses in infected colonies. However, high mortality rate demonstrates that N. ceranae is highly pathogenic to Apis mellifera. Bees die within 8 days after exposure to N. ceranae which is faster than bees exposed to N. apis. Some new viruses and bacteria have been discovered.

We investigated the pollination of Habenaria tridactylites, an endemic orchid of the Canary Islands. The entirely green, widely open flowers have a long spur containing nectar. We carried out fieldwork, a molecular clock analysis, herbarium surveys, identi¬fied pollinators by both morphology and DNA barcoding, and measured the length of floral spurs and insect tongues using a combination of traditional and innovative micro-CT scanning methods to 1) determine the pollinator of this orchid and 2) investigate correlations between local mean spur length and age, altitude and longitude of the island. Habenaria tridactylites was found to be pollinated on Tenerife by both small and intermediate sized moth species with variable tongue lengths and mostly belonging to Geometridae and to a lesser extent Crambidae, Erebidae, Noctuidae and Tortricidae. Of the sixteen moth species identified, nine are endemic to the Canary Islands or Macaronesia. The different local populations of H. tridactylites on the islands of Gran Canaria, El Hierro, La Gomera, La Palma and Tenerife with different ages and distances from mainland Africa, did not show a significant correlation of mean spur length and altitude, but did show a significant and positive linear correlation with lon¬gitude and the geological age of the island. The latter is congruent with the evolution¬ary arms race theory first proposed by Darwin, suggesting that flowers gradually evolve longer spurs and pollinators longer tongues.

This paper focuses on the systematics of the Specklinia endotrachys species complex in Costa Rica. Traditionally considered a variable species, S. endotrachys is here treated as one of at least four, albeit closely related, taxa. Of these species, S. endotrachys, S. pfavii, and S. spectabilis are described and illustrated from living material, and S. remotiflora is described and illustrated as new to science. Specklinia remotiflora is compared with S. endotrachys and S. spectabilis, from which it differs in the repent habit, lax inflorescence and campanulate flowers provided with convergent sepals and non-apiculate petals. New combinations are proposed for Pleurothallis pfavii and P. spectabilis. A lectotype is selected for Pleurothallis endotrachys. Observations on the pollination of S. remotiflora and S. spectabilis in cultivation are given.
Key words: Neotropical orchids, pollination, Specklinia endotrachys complex, Specklinia remotiflora

This chapter describes how the climate change is potentially the most severe threat to pollinator biodiversity. Mounting evidence demonstrates that there have already been biotic responses to the relatively small climate changes that have occurred this century. Pollinators such as birds, bees, butterflies, moths, flies, wasps, beetles bats and even mosquitoes are essential for food production because they transfer pollen between seed plants-impacting 35% of the world's crops. Along with providing an essential service to human populations, pollinators also have a key role in maintaining other ecosystem services including ensuring biodiversity and helping Nature to adjust to external threats such as climate change. The "pollination crisis" that is evident in declines of honeybees and native bees worldwide is due to disruption of critical balance between the two mutually interacting organisms. Anthropogenic climate change is widely expected to drive species extinct by hampering individual survival and reproduction, by reducing the amount and accessibility of suitable habitat, or by eliminating other organisms that are essential to the species in question. The potential disruption of a ubiquitous mutualistic interaction of terrestrial habitats, that between plants and their animal pollinators, via climate change is at risk.

ENGLISH
Chapter discusses several important aspects of pollination by beetles, such as biology and ecology of beetles; origin of the word "cantharophily" and the current tendency to be replaced by "pollination by beetles"; main groups of plants pollinated by beetles; Evolutionary ecology: origin of cantharophily; Adaptations to beetle pollination; Pollination and reproductive biology; Lack of studies on this pollination system so important in tropical ecosystems.

PORTUGUÊS
Capítulo aborda vários importantes aspectos da polinização por besouros, tais como biologia e ecologia dos besouros; origem da expressão "cantarofilia" e da tendência atual de se utilizar "polinização por besouros";  principais grupos de plantas polinizador por coleópteros; Ecologia evolutiva: origem da cantarofilia; Adaptações à polinização por besouros; Polinização e biologia reprodutiva; Falta de estudos sobre este sistema de polinização tão importante em ecossistemas tropicais.

Najas is the largest of the 18 hydrophilous angiosperm genera, however, study of pollination biology in the genus is largely ignored. In this study, the pollination mechanism of Najas marina L. was observed in two freshwater lakes as well as in aquaria. A unique mechanism of rapid pedicel elongation and curvature in the male flower of N. marina that brings the anther to lie opposite to the branches is reported for the first time. This process occurs before anther dehiscence and facilitates dispersal of pollen by water currents. A large number of pollen grains are dispersed in dense "clouds" for 5-10 min after anther dehiscence. Microscopic examination of pollen grains revealed the presence of numerous starch grains in the cytoplasm. These increase the gravity of the pollen grains and provide energy for pollen tube growth to a length of 2 mm in the water. The development of pollen tubes before contact with the stigma enhances the chances of the pollen to be captured by the branched stigmas. In addition, the pollen grains undergo a marked elongation of their polar axes just prior to release. The relatively long period of viability of both precocious and ungerminated pollen grains further enhances pollination. The high pollen loads observed on stigmas could account for the high seed yield in this submerged plant. The precocious pollen grains may be functionally equivalent to the filiform pollen occurring in submarine-pollinated seagrasses. This provides an example of convergent evolution in response to the pollination environment created by strong water currents.

The phenology, compatibility system, and pollinator fauna ofOpuntia polyacantha Haw. andO. phaeacantha Engelm. in southern Colorado were studied and compared. The total blooming periods overlap, but the peak of blooming differs between the species withO. polyacantha blooming first and for longer. Neither species is apomictic,O. polyacantha is largely self-incompatible andO. phaeacantha is self-compatible but may not automatically fully self-pollinate. Examination of flowering structures showed that the former has larger flowers with more perianth parts and heavier (but fewer) anthers. Further the flowers of the allogamous species are visited by greater diversity (but similar abundance) of pollinators. Medium to large bees of the generaDiadasia, Lithurge, Melissodes, Bombus, Agapostemon andMegachile were found to be effective pollinators of the Opuntias studied. The two species were compared as to their floral attributes, breeding systems, and pollinators, and the possible role of competition for pollinators is discussed with respect to its role in their evolutionary paths.

A B S T R A C T Understanding the importance of biodiversity in applied settings is a central theme for ecologists. Pollination is an essential ecosystem service, which may rely on biodiversity for effectiveness and stability. Empirical examples which link functional outcomes of increased biodiversity to pollination services are rare. To investigate the importance of wild and managed pollinator communities to apple production, we assessed the effect of wild and managed bee abundance and diversity on pollen limitation and seed set on commercial farms in New York State. Seed set increased and pollen limitation decreased with increasing wild bee species richness, functional group diversity (based on nesting, sociality, and size traits), and abundance, but not with honey bee abundance. Functional group diversity explained more variation in apple seed set than species richness. Our findings demonstrate the important role of functional complementarity of wild bees, defined here as functional group diversity, to crop pollination even in the presence of large populations of managed honey bees. Therefore, our results suggest that management of diverse pollinator communities may decrease reliance on managed honey bees for pollination services and enhance crop yields.

The structure and anatomy of mature flowers of four species of Meliosma is investigated using scanning electron and light microscopy. The vasculature of the flower, including the structure of the gynoecium, is described in detail. The mechanism of stamen maturation and pollen release is illustrated and discussed. The existence of an explosive pollination mechanism is questioned for at least part of the species. Flowers are proterandrous and fertile stamens are kept spatially separate from the style by a ring of large staminodes. Anthers are disporangiate by the loss of the adaxial pollen sacs. During maturation the filament bends progressively outwards and releases the pollen on the extension of the connective that acts as a secondary pollen presentation system. The nectary has five appendages topped with stomata secreting abundant nectar. The relationships of Sabiaceae are discussed relative to other early diverging eudicots. The significance of Sabiaceae as an isolated clade is highlighted, although some features point to a link with Menispermaceae.

The quantitative and qualitative variability in floral scent of 98 specimens of the dioecious species Silene latifolia belonging to 15 European and 19 North American populations was determined. Floral scent was collected from single flowers using dynamic headspace methods, and analysed by Micro-SPE and GC-MS methods. The flowers showed a nocturnal rhythm, and scent was emitted only at night. The amount of emitted volatiles varied greatly during the season, from 400 ng/flower/2 min in June to 50 ng/flower/2 min in August and September. The qualitative variability in the floral scent was high and different chemotypes, characterised by specific scent compounds, were found. Female and male flowers emitted the same type and amount of volatiles. The differences in floral scent composition between European and North American populations were small. Typical compounds were isoprenoids like lilac aldehyde isomers, or trans-b-ocimene, and benzenoids like benzaldehyde, phenyl acetaldehyde, or veratrole. Some of these compounds are known to attract nocturnal Lepidoptera species. The high qualitative variability is discussed in relation to the pollination biology of S. latifolia, and the results are compared with other studies investigating intraspecific variability of flower scent. (S. Dö tterl). www.elsevier.com/locate/phytochem Phytochemistry 66 (2005) 203-213 PHYTOCHEMISTRY

Species of Helicteres are pollinated mainly by hummingbirds and bats. Most species pollinated by hummingbirds have a mechanism of depositing pollen on the top of the pollinator's head such as is shown in this work for Helicteres sacarolha. H. brevispira has an unusual mechanism of depositing pollen grains under the tail or on the abdomen of the hummingbirds. The top of the birds' head may be considered an efficient place to transport pollen grains, because it is plain, easily accessible for deposition and donation of pollen and not easily accessible for grooming, while the tail is movable and inclined. Thus, H. brevispira pollinators may carry or transfer fewer amounts of pollen grains than H. sacarolha pollinators from one flower to another. If a large amount of pollen grains is lost, a higher quantity of flower or pollen has to be produced to guarantee reproductive success. Plants of H. brevispira set higher number of flowers and pollen grains per flower than H. sacarolha and have also higher rates of fruit and flower abortion. Thus, pollination efficiency of H. brevispira may be reached by high pollen and flower production. Flower change mechanism presented in this species may be also involved with the optimization of pollinator feeding and pollination efficiency.

Successful cross-pollination of Monardafistulosa is the result of a complex interaction among flower opening, the pollen-bearing areas of the pollinators and/or their behavior, and the maturation of the stigmas. The flowers open continuously from 0800-2000 h providing a temporally predictable and, if pollinator activity is high, a spatially unpredictable rich source of nectar and pollen. Recently opened flowers may reduce the ability of bees to discriminate between resource rich and poor patches and encourage systematic foraging within patches. The continuous opening of flowers coupled with protandry also results in some flowers of most capitula being in the staminate and others in the pistillate phase. Autogamy is highly unlikely due to strong protandry and the spatial separation of anthers and stigmas. Geitonogamy, at least that mediated by Bombus is unlikely because the pollen is spread over a relatively large area of the wings, which reduces the likelihood of a stigma contacting just deposited pollen. Because pollen is transferred from the much smaller coxal area of Anthophora and other bees that mistake the stigmas of early pistillate phase flowers for stamens some geitonogamy seems inevitable. However, the delayed receptivity of young stigmas to self-pollen decreases the likelihood of self-pollen germinating on such stigmas. Older stigmas are equally receptive to self-and cross-pollen and the number of pollen grains germinating and pollen tubes reaching the base of the style increases with flower age.

The rattleweed Crotalaria retusa was introduced in Brazil from Africa, and combines a series of characters that have ensured its establishment in NE Brazil. We focused on its reproductive biology and pollinator behavior to explain its reproductive success. We performed manual pollination and germination experiments, and monitored the behavior of C. retusa's main pollinators in monospecific plots, and in mixed plots where C. retusa occurred together with two congeners, Crotalaria pallida and Crotalaria lanceolata. Crotalaria retusa is self-compatible and capable of automatic selfing. Inbreeding depression was expressed at the level of percent seed germination, but not seed set. Few insects visited the inflorescences. Legitimate pollinators were two large carpenter bees, Xylocopa frontalis and Xylocopa grisescens which, together, accounted for more than 90 percent of the visits. The former foraged on C. retusa exclusively and has low pollen spread potential. The latter flew longer distances between plants and visited fewer flowers per inflorescence, potentially increasing the extent of pollen carryover, but at the risk of increasing heterospecific pollen transfer, because it visits other Crotalaria species during the same foraging bout. The different foraging strategies, allied to morphological disadvantages represented by pollen overlap on X. grisescens' body, may partially explain the much lower seed germination observed in C. pallida and C. lanceolata. These results are consistent with the hypothesis that a reduction in flower constancy may significantly depress viable seed set by increasing the chances of self-pollination.A leguminosa Crotalaria retusa, vulgarmente conhecida como chocalho ou xique-xique, foi introduzida no Brasil pela África, e combina uma série de características que facilitaram seu estabelecimento no nordeste do Brasil. Focalizamos aspectos da biologia reprodutiva e do comportamento dos seu polinizadores para explicar seu sucesso reprodutivo. Para isto realizamos tratamentos de polinização manual e germinação de sementes, e monitoramos o comportamento dos principais polinizadores em áreas monoespecíficas e em áreas onde C. retusa ocorria junto a duas congêneres, C. pallida e C. lanceolata. C. retusaé autocompatível e capaz de autofertilização espontânea. Ocorreu depressão endogâmica no nível de porcentagem de germinação de sementes, mas não no número. Pouco insetos visitaram as inflorescências. Os polinizadores legítimos foram duas abelhas de grande porte, Xylocopa frontalis e X. grisescens que representaram mais de 90 por cento das visitas. O primeiro forrageia exclusivamente em C. retusa e tem baixo potencial de dispersão polínica. O segundo voa a distâncias mais longas e visita menos flores por inflorescência, potencialmente aumentando a extensão de dispersão do pólen, mas com o risco de ampliar a transferência de pólen heteroespecífico, pois visita outras espécies de Crotalaria durante o vôo. As diferentes estratégias de forrageio, junto com a sobreposição de pólen no corpo de X. grisescens, explica em parte a baixa taxa de germinação de C. pallida e C. lanceolata. Os resultados são consistentes com a hipótese de que uma redução na constância floral pode deprimir significativamente a produção de sementes viáveis, ao aumentar as chances de autopolinização.

† Background and Aims Pollinator-mediated selection and evolution of floral traits have long fascinated evolutionary ecologists. No other plant family shows as wide a range of pollinator-linked floral forms as Orchidaceae. In spite of the large size of this model family and a long history of orchid pollination biology, the identity and specificity of most orchid pollinators remains inadequately studied, especially in the tropics where the family has undergone extensive diversification. Angraecum (Vandeae, Epidendroideae), a large genus of tropical Old World orchids renowned for their floral morphology specialized for hawkmoth pollination, has been a model system since the time of Darwin. † Methods The pollination biology of A. cadetii, an endemic species of the islands of Mauritius and Reunion (Mascarene Islands, Indian Ocean) displaying atypical flowers for the genus (white and medium-size, but short-spurred) was investigated. Natural pollinators were observed by means of hard-disk camcorders. Pollinator-linked floral traits, namely spur length, nectar volume and concentration and scent production were also investigated. Pollinator efficiency ( pollen removal and deposition) and reproductive success (fruit set) were quantified in natural field conditions weekly during the 2003, 2004 and 2005 flowering seasons (January to March). † Key Results Angraecum cadetii is self-compatible but requires a pollinator to achieve fruit set. Only one pollinator species was observed, an undescribed species of raspy cricket (Gryllacrididae, Orthoptera). These crickets, which are nocturnal foragers, reached flowers by climbing up leaves of the orchid or jumping across from neighbouring plants and probed the most 'fresh-looking' flowers on each plant. Visits to flowers were relatively long (if compared with the behaviour of birds or hawkmoths), averaging 16 . 5 s with a maximum of 41 . 0 s. At the study site of La Plaine des Palmistes (Pandanus forest), 46 . 5 % of flowers had pollen removed and 27 . 5 % had pollinia deposited on stigmas. The proportion of flowers that set fruit ranged from 11 . 9 % to 43 . 4 %, depending of the sites sampled across the island. † Conclusions Although orthopterans are well known for herbivory, this represents the first clearly supported case of orthopteran-mediated pollination in flowering plants.

The genus Zygostates Lindl. (Orchidaceae) comprises about 20 species of small Neotropical epiphytic plants, represented in its southernmost limit by the species Z. alleniana. In this paper, we studied morphological and anatomical floral characteristics of this species related to pollination mechanism. We confirmed the presence of the unicellular trichomes on the base of the lip and side lobes secreting oil, constituting a trichomal elaiophore. The oil is deposited beneath the cuticle at the apex of the trichomes forming small blisters. The oil could represent a reward for the species Lophopedia nigrispinis, which would be a potential pollinator of Z. alleniana in a natural area within the geographic range of this plant species. Moreover, we prove that the reconfiguration of the pollinaruim is due to the dehydration of the walls cell. This reconfiguration could favor cross-pollination mechanism already described for other species of the family Orchidaceae. Finally, we discuss the floral characters present in Z. alleniana with closely related species.

Dactylorhiza viridis is generally pollinated by Coleoptera (beetles) and Hymenoptera (sawflies, wasps, bees, and ants). This orchid offers nectar at the lip base as well as in the spur. In the Dolomites, a calcareous mountain region in Italy, we found reasonable numbers of Dact. viridis, all growing in the vicinity of nests of the ant Formica (Coptoformica) exsecta. The ants had discovered the nectar of the orchid as a supplemental food source and acted as pollinators of Dact. viridis, carrying, on average , three pollinaria on their head. Their repeated visits led to a high degree of geitonogamy. This is the first mention of ant pollination of Dact. viridis.

Attracting potential pollinators is vital for orchids, for most rely on insects for the transport of the genetic material, the pollinia or pollinaria. Nectar is an important attractant that serves as a food reward for the visiting insects. In this part of our series we will discuss two quite different ways of offering nectar to the visitors, illustrated in Gymnadenia conopsea and Neottia ovata. We will also discuss how this effects the potential visitor spectrum.