Pollination services in the UK: how important are honeybees?

Pollination services are known to provide substantial benefits to human populations and agriculture in particular. Although many species are known to provide pollination services, honeybees (Apis mellifera) are often assumed to provide the majority of these services to agriculture. Using data from a range of secondary sources, this study assesses the importance of insect pollinated crops at regional and national scales and investigates the capacity of honeybees to provide optimal pollination services to UK agriculture. The findings indicate that insect pollinated crops have become increasingly important in UK crop agriculture and, as of 2007, accounted for 20% of UK cropland and 19% of total farmgate crop value. Analysis of honeybee hive numbers indicates that current UK populations are only capable of supplying 34% of pollination service demands even under favourable assumptions, falling from 70% in 1984. In spite of this decline, insect pollinated crop yields have risen by an average of 54% since 1984, casting doubt on long held beliefs that honeybees provide the majority of pollination services. Future land use and crop production patterns may further increase the role of pollination services to UK agriculture, highlighting the importance of measures aimed at maintaining both wild and managed species.

Enhancement of buffer strips can improve provision of multiple ecosystem services

Farmland invertebrates play a pivotal role in the provision of ecosystem services, i.e. services that benefit humans. For example, bumblebees, solitary bees and honeybees, are crucial to the pollination of many of the world's crops and wildflowers, with over 70% of the world's major food crops dependent on the pollination services provided by these insects. The larvae of some butterfly species are considered to be pests; however, together with moth and sawfly larvae, they represent a key dietary component for many farmland birds. Spiders and ground beetles predate on crop pests including aphids, whilst soil macrofauna such as earthworms are vital for soil fertility services and nutrient recycling. Despite their importance, population declines of invertebrates have been observed during the last sixty years in the UK and NW Europe. For example, seven UK bumblebee species are in decline, and in the last 20 years, the species Bombus subterraneus (short-haired bumblebee) has become extinct, whilst there was a 54% decline in honeybee colony numbers in England from 1985 to 2005. Comparable trends have been documented for butterflies with a 23% decline in UK farmland species such as Anthocharis cardamines (orange tip) between 1990 and 2007. These declines have been widely attributed to the modern intensive arable management practices that have been developed to maximise crop yield. For example, loss and fragmentation of foraging and nesting habitats, including species-rich meadows and hedgerows, have been implicated in the decline of bees and butterflies. Increased use of herbicides and fertilisers has caused detrimental effects on many plant species with negative consequences for predatory invertebrates such as spiders and beetles which rely on plants for food and shelter.

Assembly of Recombinant Israeli Acute Paralysis virus capsids

The dicistrovirus Israeli Acute Paralysis Virus (IAPV) has been implicated in the worldwide decline of honey bees. Studies of IAPV and many other bee viruses in pure culture are restricted by available isolates and permissive cell culture. Here we show that coupling the IAPV major structural precursor protein ORF2 to its cognate 3C-like processing enzyme results in processing of the precursor to the individual structural proteins in a number of insect cell lines following expression by a recombinant baculovirus. The efficiency of expression is influenced by the level of IAPV 3C protein and moderation of its activity is required for optimal expression. The mature IAPV structural proteins assembled into empty capsids that migrated as particles on sucrose velocity gradients and showed typical dicistrovirus like morphology when examined by electron microscopy. Monoclonal antibodies raised to recombinant capsids were configured into a diagnostic test specific for the presence of IAPV. Recombinant capsids for each of the many bee viruses within the picornavirus family may provide virus specific reagents for the on-going investigation of the causes of honeybee loss.

Diesel exhaust rapidly degrades floral odours used by honeybees

Honeybees utilise floral odours when foraging for flowers; we investigated whether diesel exhaust pollution could interrupt these floral odour stimuli. A synthetic blend of eight floral chemicals, identified from oilseed rape, was exposed to diesel exhaust pollution. Within one minute of exposure the abundances of four of the chemicals were significantly lowered, with two components rendered undetectable. Honeybees were trained to recognise the full synthetic odour mix; altering the blend, by removing the two chemicals rendered undetectable, significantly reduced the ability of the trained honeybees to recognize the altered odour. Furthermore, we found that at environmentally relevant levels the mono-nitrogen oxide (NOx) fraction of the exhaust gases was a key facilitator of this odour degradation. Such changes in recognition may impact upon a honeybee's foraging efficiency and therefore the pollination services that they provide.

Ecological and social drivers of coffee pollination in Santander, Colombia

Bees and other insects provide pollination services that are key to determining the fruit set on coffee plantations. These pollination services are influenced by local ecology as well as human factors, both social and economic. To better understand these different factors, we assessed their effect on pollinators and coffee pollination services in Santander, Colombia. We quantified the effect of key ecological drivers on pollinator community composition, such as the method of farm management (either conventional or organic) and the surrounding landscape composition, specifically the proximity to forest. We found that ambient levels of pollination services provided by the local pollinator fauna (open pollination) accounted for a 10.5 ± 2.0% increase in final coffee fruit set, and that the various pollinators are affected differently by the differing factors. For example, our findings indicate that conventional farm management, using synthetic inputs, can promote pollinators, especially if they are in close proximity to natural forest fragments. This is particularly true for stingless bees. Honeybee visitation to coffee is also positively influenced by the conventional management of farms. Factors associated with greater numbers of stingless bees on farms include greater shade cover, lower tree densities, smaller numbers and types of trees in bloom, and younger coffee plantations. A forested landscape close to farms appears to enhance these factors, giving increased stability and resilience to the pollinating bees and insects. However we found that organic farms also support diverse pollinator communities, even if distant from forest fragments. The contribution of honeybees to pollination value (US$129.6/ha of coffee) is greater than that of stingless bees (US$16.5/ha of coffee). Since the method of farm management has a major impact on the numbers and types of pollinators attracted to farms, we have analysed the statistically significant social factors that influence farmers’ decisions on whether to adopt organic or conventional practices. These include the availability of technology, the type of landowner (whether married couples or individual owners), the number of years of farmers’ formal education, the role of institutions, membership of community organizations, farm size, coffee productivity and the number of coffee plots per farm. It is hoped that the use of our holistic approach, which combines investigation of the social as well as the ecological drivers of pollination, will help provide evidence to underpin the development of best practices for integrating the management of pollination into sustainable agricultural practices.

Cytochrome-b variation in Apis mellifera samples and its association with COI-COII patterns

Five Mbo I (Mbo-A, Mbo-M, Mbo-C(1), Mbo-C(2) and Mbo-C(3)) and Hinf I (Hinf-1 to Hinf-5) patterns were observed in Apis mellifera samples after restriction of a 485 bp fragment of the mitochondrial cytochrome-b (cyt-b) gene. Associating the cyt-b Restriction fragment length polymorphism (RFLP) pattern of each sample to its respective previously established COI-COII (Dra I sites) pattern, five restriction patterns (Mbo-C(1), Mbo-C(2), Mbo-C(3), Hinf-1 and Hinf-4) were observed in samples of maternal origin associated to the evolutionary branch C. No deletions or insertions were observed and the nucleotide substitution rate was estimated at 5.4%. Higher nucleotide diversity was observed among the branch C-haplotypes when compared with A and M lineages. Further studies are needed to confirm if the cyt-b + COI-COII haplotypes help to assign certain phylogeographic patterns to the branch C and to clarify phylogenetic relationships among A. mellifera subspecies.

A non-invasive method for silencing gene transcription in honeybees maintained under natural conditions

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Application of an HPLC method for analysis of propolis extract

Propolis obtained from honeybee hives has been widely used in medicine, cosmetics, and industry due to its versatile biological activities (antioxidant, antimicrobial, fungicidal, antiviral, antiulcer, immunostimulating, and cytostatic). These activities are mainly attributed to the presence of flavonoids in propolis, which points out the interest in quantifying these constituents in propolis preparations, as well as validation of analytical methodologies. High-performance liquid chromatography (HPLC) methods have been reported to quantify isolated flavonoids or these compounds in complex biological matrices, such as herbal raw materials and extractive preparations. An efficient, precise, and reliable method was developed for quantification of propolis extractive solution using HPLC with UV detection. The chromatograms were obtained from various gradient elution systems (GES) tested in order to establish the ideal conditions for the analysis of propolis extractive solution, using methanol and water: acetonitrile (97.5 : 2.5, v/v) as mobile phase. Gradient reversed phase chromatography was performed using a stainless steel column (250 x 4.6 mm i.d., 5 mum) filled with Chromsep RP 18 (Varian), column temperature at 30.0 +/- 0.1degreesC and detection at 310 nm. The main validation parameters of the method were also determined. The method showed linearity for chrysin in the range 0.24-2.4 mug mL(-1) with good correlation coefficients (0.9975). Precision and accuracy were determined. The obtained results demonstrate the efficiency of the proposed method. The analytical procedure is reliable and offers advantages in terms of speed and cost of reagents.

Inhibitory effect of propolis and bee venom on the mutagenicity of some direct- and indirect-acting mutagens

The antimutagenic effect of ethanolic extract of propolis (EEP) and honeybee (Apis mellifera) venom, both collected in the State of Sb Paulo, Brazil, was assessed by the Salmonella/microsome assay upon direct- and indirect-acting mutagens. EEP had inhibitory effect (in an ascending order) on the mutagenicity power of daunomycin (TA102), benzo(a)pyrene (TA100), and aflatoxin B-1(TA98) and the venom acted against the mutagenicity of 4-nitro-o-phenylenediamine (TA98) and daunomycin (TA102). (C) 1999 Wiley-Liss, Inc.

Protective action of propolis on the rat colon carcinogenesis

Propolis is a honeybee product with several biological and therapeutical properties. Its effect on the process of colon carcinogenesis and DNA damage were evaluated in the male Wistar rats using the aberrant crypt foci (ACF) assay and the comet assay, respectively. For both tests, animals were treated with the colon carcinogen 1,2 dimethylhydrazine (DMH, 40 mg/kg, s.c.) for 2 weeks (two injections/week) in order to induce both DNA damage and ACF. The animals were divided into groups that received propolis (ethanolic extract) at three different doses (10, 30, and 90 mg/kg b.w., by gavage), either simultaneously or after DMH treatment. For the comet assay, peripheral blood samples were collected 4 h after the last DMH treatment. All animals were sacrificed at the 5th week for evaluation of ACF. The results show that only the intermediate dose (30 mg/kg) of propolis, administered after DMH initiation, is significantly associated to a smaller number of aberrant crypts in the distal colon. No effect on DNA damage in peripheral blood cells, however, was verified by the comet assay. These data suggest that propolis has a protective influence on the process of colon carcinogenesis, suppressing the development of preneoplastic lesions, and probably exerts no protection against the initiation of carcinogenesis.

Modifying effect of propolis on dimethylhydrazine-induced DNA damage but not colonic aberrant crypt foci in rats

Propolis is a honeybee product with several biological and therapeutic properties, including antimutagenic and anticarcinogenic activities. The effects of an aqueous extract of propolis (AEP) were evaluated on the formation of 1,2-dimethylhydrazine (DMH)-induced aberrant crypt foci (ACF) and DNA damage in the colon of male Wistar rats by the ACF and Comet assays, respectively. AEP was administered orally at 0.01%, 0.03%, 0.1%, and 0.3% in the drinking water, which resulted in doses of approximately 12, 34, 108, and 336 mg/kg body weight/day. Animals were also given a single subcutaneous injection of 40 mg/kg DMH and sacrificed 4 hr later for evaluating DNA damage, or 4 doses of 40 mg/kg DMH, administered 2 doses/week for 2 weeks, and sacrificed 12 weeks after the last injection for evaluating ACF development in the distal colon. Administration of AEP either simultaneously with or after the DMH treatment resulted in no statistically significant reduction of ACF. In contrast, 0.01%, 0.03%, and 0.3% AEP, given simultaneously with DMH, reduced DNA damage induction in the mid and distal colon. However, 0.3% AEP alone increased DNA damage in the colon. In conclusion, AEP had no effect on the formation of DMH-induced ACF in rat colon, but it modulated DMH-induced DNA damage in colon cells. Further investigations are recommended in order to establish the conditions under which propolis produces either protective or deleterious effects. (C) 2004 Wiley-Liss, Inc.

The effects of Brazilian and Bulgarian propolis in vitro against Salmonella Typhi and their synergism with antibiotics acting on the ribosome

Salmonella enterica serovar Typhi is the causative agent of typhoid fever in humans, and the use of antibiotics is essential for controlling this infection; however, the excessive use of antibiotics may select resistant strains. Propolis is a honeybee product and its antimicrobial activity has been intensively investigated. Thus, the objective of this study was to investigate a possible synergism between propolis (collected in Brazil and Bulgaria) and antibiotics acting on the ribosome (chloramphenicol, tetracycline and neomycin) against Salmonella Typhi in vitro. The synergism was investigated by using 1/2 and 1/4 of the minimum inhibitory concentration for propolis and these antimicrobial agents, evaluating the number of viable cells according to the incubation time. Brazilian propolis showed a bacteriostatic action against S. Typhi, while Bulgarian propolis showed a bactericidal activity and a synergistic effect with the three antibiotics. Variations in the biological assays might be due to the differences in their chemical compositions. Based on the results, one may conclude that Bulgarian propolis showed an important antibacterial action, as well as a synergistic effect with antibiotics acting on the ribosome, which points out a possible therapeutic strategy evaluating the use of propolis preparations for the treatment of Salmonella Typhi infection.

Antibacterial effects of Brazilian and Bulgarian propolis and synergistic effects with antibiotics acting on the bacterial DNA and folic acid

Propolis is a honeybee product that has been used since ancient times because of its therapeutic effects. It can be used in the development of alternative therapies for the treatment of many diseases, and because propolis shows antibacterial action, this work was carried out in order to investigate a possible synergism between propolis and antibiotics acting on DNA (ciprofloxacin and norfloxacin) and on the metabolism (cotrimoxazole) against Salmonella Typhi. Propolis samples collected in Brazil and Bulgaria were compared in these assays, and the synergism was investigated by using 1/2 and 1/4 of the minimal inhibitory concentration for propolis and antibiotics, evaluating the number of viable cells according to the incubation time. Brazilian and Bulgarian propolis showed antibacterial activity, but no synergistic effects with the three tested antibiotics were seen. Previous works by our laboratory have revealed that propolis has synergistic effects with antibiotics, acting on the bacterial wall and ribosome, but it does not seem to interact with antibiotics acting on DNA or folic acid, and only a bacteriostatic action was seen in these assay conditions.

New Nanostructured Silica Adjuvant (SBA-15) Employed to Produce Antivenom in Young Sheep Using Crotalus durissus terrificus and Apis mellifera Venoms Detoxified by Cobalt-60

Equine antivenom is considered the only treatment for animal-generated envenomations, but it is costly. The study aimed to produce Apis mellifera (Africanized honeybee) and Crotalus durissus terrificus (C.d.t.) antivenoms using nanostructured silica (SBA-15) as adjuvant and cobalt-60 (60Co)-detoxified venoms utilizing young sheep. Natural and 60Co-irradiated venoms were employed in four different hyperimmunization protocols. Thus, 8 groups of 60- to 90-d-old sheep were hyperimmunized, enzyme-linked immunosorbent assay (ELISA) serum titers collected every 14 d were assessed clinically daily, and individual weight were measured, until d 84. Incomplete Freund's (IFA) and nanostructured silica (SBA15) adjuvants were compared. The lethal dose (LD50) for both venoms was determined following intraperitoneal (ip) administration to mice. High-performance liquid chromatography on reversed phase (HPLC-RP) was used also to measure the 60Co irradiation effects on Apis venom. At the end of the study, sheep were killed in a slaughterhouse. Kidneys were histologically analyzed. LD50 was 5.97 mg/kg Apis and 0.07 mg/kg C.d.t. for native compared to 13.44 mg/kg Apis and 0.35 mg/kg C.d.t. for irradiated venoms. HPLC revealed significant differences in chromatographic profiles between native and irradiated Apis venoms. Native venom plus IFA compared with SBA-15 showed significantly higher antibody titers for both venoms. Apis-irradiated venom plus IFA or SBA-15 displayed similar antibody titers but were significantly lower when compared with native venom plus IFA. Weight gain did not differ significantly among all groups. 60Co irradiation decreased toxicity and maintained venom immunogenic capacity, while IFA produced higher antibody titers. SBA-15 was able to act as an adjuvant without producing adverse effects. Hyperimmunization did not affect sheep weight gain, which would considerably reduce the cost of antiserum production, as these sheep were still approved for human consumption even after being subjected to hyperimmunization.

Atividade antimicrobiana de própolis de Apis mellifera obtidas em três regiões do Brasil

As propriedades biológicas da própolis de Apis mellifera são amplamente relatadas sendo comuns variações nas mesmas em função da região onde foram produzidas. A ação antimicrobiana de própolis obtidas em três regiões do Brasil (Botucatu-SP, Mossoró-RN e Urubici-SC) foi investigada sobre linhagens isoladas de infecções clínicas humanas (Staphylococcus aureus, Escherichia coli, Enterococcus sp, Pseudomonas aeruginosa e Candida albicans). Foram preparados extratos alcoólicos de própolis (EAP) e determinada a Concentração Inibitória Mínima (CIM) seguida do cálculo da CIM90%. A própolis de Botucatu foi a mais eficiente sobre S. aureus (0,3%v/v), Enterococcus sp (1,1%v/v) e C. albicans (2,1% v/v). Para E. coli, a própolis eficiente foi de Urubici (7,0%v/v) e para P. aeruginosa a de Mossoró (5,3%v/v). Os resultados mostram maior sensibilidade das bactérias Gram positivas e levedura em relação às Gram negativas. É possível concluir que, para os microrganismos testados e amostras de própolis testadas, há diferenças na atividade antimicrobiana em função do local de produção e que isso se explica pela diferença de composição química da própolis.