Honey Storage Research Articles

A critical number of workers in a honeybee colony triggers investment in reproduction.

Social insect colonies, like individualorganisms, must decide as they develop how to allocate optimally their resources among survival, growth, and reproduction. Only when colonies reach a certain state do they switch from investing purely in survival and growth to investing also in reproduction. But how do worker bees within a colony detect that their colony has reached the state where it is adaptive to begin investing in reproduction? Previous work has shown that larger honeybee colonies invest more in reproduction (i.e., the production of drones and queens), however, the term 'larger' encompasses multiple colony parameters including number of adult workers, size of the nest, amount of brood, and size of the honey stores. These colony parameters were independently increased in this study to test which one(s) would increase a colony's investment in reproduction via males. This was assayed by measuring the construction of drone comb, the special type of comb in which drones are reared. Only an increase in the number of workers stimulated construction of drone comb. Colonies with over 4,000 workers began building drone comb, independent of the other colony parameters. These results show that attaining a critical number of workers is the key parameter for honeybee colonies to start to shift resources towards reproduction. These findings are relevant to other social systems in which a group's members must adjust their behavior as a function of the group's size.

Reviews of Science for Science Librarians: An Update on Honeybee Colony Collapse Disorder

Honeybee Colony Collapse Disorder (HCCD or CCD) is an epidemic in which worker bees mysteriously disappear from hives, despite the presence of a living queen and immature brood—the care and feeding of both being their ordinary preoccupation—and sometimes even despite the presence of ample supplies of stored honey that would sustain them. While it understandably has a great impact on honey production, the greatest significance of HCCD is its effects on tens of billions of dollars’ worth of crops that depend on bees to pollinate their flowers so as to have higher rates of seed or fruit set. A review of the literature done in 2008, covering journal articles up through 2007, disclosed a wide variety of potential causes for HCCD being put forth, largely in articles confined to the literature of entomology and apiology. This update, which covers 2008–2013, suggests that the number of factors still seriously implicated has actually diminished and that the majority of papers today favor multifactorial explanations, which now appear in much higher visibility journals in science, especially multiscience and microbiology.

Nosema ceranae and queen age influence the reproduction and productivity of the honey bee colony

SummaryThe strength of the honey bee colony and the quality concerning brood production, number of worker bees and honey yield depend substantially upon the characteristics of the queen. Reproductive and productive capacities of the colony, as two important physiological qualities can depend a great deal on the age of the queen. Over the years, the laying ratio of queens could decrease depending on the age; therefore colonies headed by one-year-old queens have proven to be more efficient considering colony population and honey production than ones with older queens. Nosema ceranae infection is a possible reason for the decrease in reproductive capacities and the reduction in the honey production of infected colonies. With the help of numerous pheromones, the queen can preserve colony homeostasis, however exhausted by N. ceranae infection she might compromise the renewal of worker population. The aim of this research is to investigate the influence of N. ceranae on reproduction and productivity of honey bee colonies headed by queens of different age. Experiment was conducted on 27 honey bee colonies equalized with regard to brood, food source, number of worker bees and Nosema infection. In the three year investigation period (2009–2012), Nosema detection, identification and spore load per each colony, as well as parameters of colony reproduction (such as uncapped and capped brood area, queen egg-laying rate and colony strength) and productivity (the total extracted honey and the winter honey stores) were recorded. Concerning the influence of the age of the queens on followed parameters we compared one, two and three-years old queens and found significantly higher reproductive and productive values in favour of younger ones. Significant differences regarding the effects of N. ceranae infection on productive and reproductive characteristics could be explained with a higher capacity of one year old queens to compensate the effects of Nosema infection; a capacity which gradually declines in the second and the third year.

Factors That Affect Consumption Patterns and Market Demands for Honey in the Kingdom of Saudi Arabia

Despite the significant annual consumption of honey in Saudi Arabia, information gaps remain with regard to the marketing and market structure of honey along the value chain. This study analyzed the major factors that influenced the consumption, expenditure patterns, and demand of honey in Saudi Arabia. This study forecasted the near-future expected market demands for honey in Saudi Arabia by collecting and analyzing the primary data using questionnaires. A total of 331 respondents from representative regions and large cities were randomly selected and interviewed. The data were analyzed using qualitative and quantitative methods as well as appropriate econometric models. Respondents characterized honey quality using organoleptic words, and these characterizations varied based on the relative significance of perception parameters. Taste, aroma, physical state, and color had aggregated average scores of 4.58, 4.44, 3.54, and 3.28, respectively. In addition to the above parameters, honey source, brand name, and confidence in the producers influenced its perceived quality. The major outlets for honey in Saudi Arabia included producers, specialized honey stores, and auction markets in major cities during the harvesting seasons. Medication, food, and sweetening were the major motivations for buying honey in the Saudi market, with aggregate scores of 4.52, 3.71, and 1.52, respectively. Significant honey price variations were observed within and among different honeys and packaging volumes; this finding might be due to factors such as botanical and geographical origins, package volume size economics (i.e., bulk purchases), honey variety blending, brand names, and producer policies. The average price of locally produced honey was approximately $73 per kg, which is 10 times more than the average price of honey in the US and the EU. The estimated consumption/income elasticity was 0.27. These results suggest that honey is a basic commodity in Saudi Arabia. Based on econometric model forecasts, the Saudi market demand for honey is expected to reach approximately 29,784 tons in 2025.

A new look on protein-polyphenol complexation during honey storage: is this a random or organized event with the help of dirigent-like proteins?

Honey storage initiates melanoidin formation that involves a cascade of seemingly unguided redox reactions between amino acids/proteins, reducing sugars and polyphenols. In the process, high molecular weight protein-polyphenol complexes are formed, but the mechanism involved remains unknown. The objective of this study was twofold: to determine quantitative and qualitative changes in proteins in honeys stored for prolonged times and in different temperatures and to relate these changes to the formation of protein-polyphenol complexes. Six -month storage decreased the protein content by 46.7% in all tested honeys (t-test, p<0.002) with the rapid reduction occurring during the first three month. The changes in protein levels coincided with alterations in molecular size and net charge of proteins on SDS –PAGE. Electro-blotted proteins reacted with a quinone-specific nitro blue tetrazolium (NBT) on nitrocellulose membranes indicating that quinones derived from oxidized polyphenols formed covalent bonds with proteins. Protein-polyphenol complexes isolated by size-exclusion chromatography differed in size and stoichiometry and fall into two categories: (a) high molecular weight complexes (230–180 kDa) enriched in proteins but possessing a limited reducing activity toward the NBT and (b) lower molecular size complexes (110–85 kDa) enriched in polyphenols but strongly reducing the dye. The variable stoichiometry suggest that the large, “protein-type” complexes were formed by protein cross-linking, while in the smaller, “polyphenol-type” complexes polyphenols were first polymerized prior to protein binding. Quinones preferentially bound a 31 kDa protein which, by the electrospray quadrupole time of flight mass spectrometry (ESI-Qtof-MS) analysis, showed homology to dirigent-like proteins known for assisting in radical coupling and polymerization of phenolic compounds. These findings provide a new look on protein-polyphenol interaction in honey where the reaction of quinones with proteins and polyphenols could possibly be under assumed guidance of dirigent proteins.

Honey bee colonies from different races show variation in defenses against the varroa mite in a ‘common garden’

AbstractHoney bee [Apis mellifera L. (Hymenoptera: Apidae)] genetic diversity may be the key to responding to novel health challenges faced by this important pollinator. In this study, we first compared colonies of four honey bee races, A. m. anatoliaca, A. m. carnica, A. m. caucasica, and A. m. syriaca from Turkey, with respect to honey storage, bee population size, and defenses against varroa. The mite Varroa destructor Anderson &amp; Trueman (Acari: Varroidae) is an important pest of honey bee colonies. There are genetic correlates with two main defenses of bees against this parasite: hygienic behavior, or removing infested brood, and grooming, which involves shaking and swiping off mites and biting them. In the second part of this study, we examined the relationship of these two types of defenses, hygiene and grooming, and their correlation with infestation rates in 32 genetically diverse colonies in a ‘common garden’ apiary. Mite biting was found to be negatively correlated with mite infestation levels.

Task Specialization and Odor Effects on Proboscis Extension Conditioning in Bumblebees (Bombus huntii)

Workers in a social insect colony have distinct experiences that may affect their performance in a learning task. In this study using free-foraging and flight-cage bumblebee Bombus huntii colonies, the strength of olfactory proboscis extension conditioning (PEC) was affected by a bee’s task specialization as a nurse or forager and the stimulus odor. Nurses (n = 26) learned to respond to the odors 1-hexanol and lavender, but foragers (n = 25) had inhibited conditioning to both odors. More nurses (73 %) than foragers (48 %) had at least one conditioned response (CR), and nurses displayed significantly more CRs than foragers. As expected, a pseudoconditioned control group (n = 9) showed very few CRs. Among bees that were given a second day of trials, nurses—but not foragers—showed modest improvement. Such strong inhibition of PEC has not been described in honeybee or bumblebee foragers. The stimulus odor also affected conditioning strength in nurses. Lavender, a familiar odor, elicited earlier and more CRs than 1-hexanol. We propose that learning floral odors in the context of foraging may inhibit PEC in bumblebee foragers, whereas exposure to odors in the honey stores may prime subsequent learning in nurses.

Honey bee lines selected for high propolis production also have superior hygienic behavior and increased honey and pollen stores

Honey bees use propolis to defend against invaders and disease organisms. As some colonies produce much more propolis than others, we investigated whether propolis collecting is associated with disease resistance traits, including hygienic behavior and resistance to the parasitic bee mite, Varroa destructor. The three highest (HP) and three lowest propolis-producing (LP) colonies among 36 Africanized honey bee colonies were initially selected. Queens and drones from these colonies were crossed through artificial insemination to produce five colonies of each of the following crosses: HP♀ X HP♂, LP♀ X HP♂, HP♀ X LP♂, and LP♀ X LP♂. Colonies headed by HP♀ X HP♂ queens produced significantly more propolis than those with HP♀ X LP♂ and LP♀ X HP♂ queens and these in turn produced significantly more propolis than those headed by LP♀ X LP♂ queens. The brood cell uncapping rate of the high-propolis-producing colonies in the hygienic behavior test was significantly superior to that of the other groups. The LP X LP group was significantly less hygienic than the two HP X LP crosses, based on the evaluation of the rate of removal of pin-killed pupae. The HP X HP colonies were significantly more hygienic than the other crosses. No significant differences were found in mite infestation rates among the groups of colonies; although overall, colony infestation rates were quite low (1.0 to 3.2 mites per 100 brood cells), which could have masked such effects. Honey and pollen stores were significantly and positively correlated with propolis production.

Queen excluders enhance honey production in African honey bees, Apis mellifera, by limiting brood rearing during peak nectar flow

SummaryUnlike honey bees in temperate regions, those in tropical Africa exhibit a strong tendency towards continuous brood rearing rather than storing honey, which is a behaviour that lowers both the productivity and commercial value of African bees. In this study, the possibility of maintaining a balance in resource allocation between brood rearing and honey storage was assessed. Twelve colonies were examined, half of which were fitted with queen excluders three weeks before an expected honey harvest, while half were used as controls. Data on the honey yields and brood populations of the colonies were collected during four flowering seasons over a two-year period. The mean brood populations of all of the colonies did not differ significantly when the queen excluders were inserted into the six treatment colonies. However, at honey harvest, three weeks later, there was a highly significant difference in the mean brood population between the treatment and control groups. Colonies without queen excluders continued to rear brood, even during peak honey flow periods. The partial limiting of queen egg laying using queen excluders significantly reduced the average colony brood population compared to the control group at peak honey flow. The seasonal average honey yields were significantly different between the control and treatment groups. Under African conditions, in which bees tend to rear brood continuously even at peak honey flow and when flowering periods are short, the use of queen excluders during such periods would probably enhance honey yields of colonies.

Sugar concentration influences decision making in &amp;lt;i&amp;gt;Apis mellifera&amp;lt;/i&amp;gt; L. workers during early-stage honey storage behaviour

Decision making in honeybees is based on information which is acquired and processed in order to make choices between two or more alternatives. These choices lead to the expression of optimal behaviour strategies such as floral constancy. Optimal foraging strategies such as floral constancy improve a colony’s chances of survival, however to our knowledge, there has been no research on decision making based on optimal storage strategies. Here we show, using diagnostic radioentomology, that decision making in storer bees is influenced by nectar sugar concentrations and that, within 48 hours of collection, honeybees workers store carbohydrates in groups of cells with similar sugar concentrations in a nonrandom way. This behaviour, as evidenced by patchy spatial cell distributions, would help to hasten the ripening process by reducing the distance between cells of similar sugar concentrations. Thus, colonies which exhibit optimal storage strategies such as these would have an evolutionary advantage and improve colony survival expectations over less efficient colonies and it should be plausible to select colonies that exhibit these preferred traits.

Honey bee (Apis mellifera capensis/A. m. scutellata hybrid) nesting behavior in the Eastern Cape, South Africa

Little is known about the natural history of wild honey bee (Apis mellifera) colonies in the Eastern Cape Province of South Africa. The goal of this research was to examine nest site characteristics of honey bee (A. m. capensis/A. m. scutellata hybrid) colonies sampled from a variety of habitats (nature reserves, livestock farms, and an urban setting) in the Eastern Cape. We also determined how nest site location related to various colony strength parameters. In general, colonies not nesting in ground cavities tended to nest in locations >6 m high when nesting in cliffs and buildings and >2 m high when nesting in trees. Colonies typically nested in cavities whose entrances faced a southeasterly direction and were ~40 L in volume. We sampled a subset of colonies to determine the relationship between nest type and the following colony strength parameters: total area of comb in the colony, the volume of stored honey, pollen, and brood, adult bee population, the weight per adult bee, and the bee/nest cavity volume ratio. In general, colonies nesting in cliffs tended to be stronger than those nesting in the ground or trees. Our findings provide new insights into the nesting biology of honey bees in the Eastern Cape, South Africa, perhaps leading to the formation of conservation recommendations for honey bees in this region.

The effect of different varroacides on the acidity of winter stores and honey stores

Summary. The aim of the study was to assess the effect of selected varroacides on the pH of winter honey stores, spring honey stores, and summer honey stores. With this aim, five groups, each consisting of five colonies, were established. The control group was composed of colonies that were not treated for varrosis. The other groups were treated with oxalic acid, formic acid, Apivarol, and Bee Vital Hive Clean, respectively. The acidity of honey stores was determined with the testo 205 pH-meter. In each colony, pH of centrifuged samples of the winter honey stores, and spring and summer honey was measured in triplicate. Oxalic acid was found to lower the pH of the winter honey stores significantly (control: pH = 3.65, winter honey stores: pH = 3.29) and of the spring honey (control pH = 3.87, spring honey pH = 3.73). Formic acid significantly decreased the pH of the summer honey (control pH = 3.73, summer honey pH = 3.56). Apivarol and Bee Vital Hive Clean did not exhibit any significant impact on the pH of the winter honey stores or honey.

Extreme Effects of Season on the Foraging Activities and Colony Productivity of a Stingless Bee (Melipona asilvaiMoure, 1971) in Northeast Brazil

This study reports the influence of season on foraging activities and internal colonial parameters ofMelipona asilvaiin an Atlantic forest area of northeast Brazil. We used video cameras connected to a PC to monitor all departures and returns of foragers and the types of materials they carried. Foraging activities decreased almost 90% from dry to rainy seasons, but temperature and humidity were not the main factors influencing departures. Observed honey storage and an extreme cutback in activities during the rainy period suggest a seasonal diapause in this species.

Beneficial Effects of Bacillus subtilis subsp. subtilis Mori2, a Honey-Associated Strain, on Honeybee Colony Performance.

A Bacillus spp. strain isolated from a honey sample in Morillos (Salta, Argentina) was phylogenetically characterized as B. subtilis subsp. subtilis Mori2. The strain was administered to bee colonies as a monoculture in one litre of sugarcane syrup (125g/L) at a final concentration of 10(5)spores/mL to evaluate the bee colony performance. The treated colony was monitored, and any changes were compared with the control hives. All conditions were identical (weather, nourishment and supervision), except for the Bacillus spore supplement. The new nourishment, which was administered monthly from May to December 2010, was accepted by the bees and consumed within ca. 24-48h. Photograph records and statistic analyses revealed significant differences in the open and operculated brood areas between the treated and control groups. The status of the colony improved after the second administration of the Bacillus spores until the end of the experiment. A higher number of bees were counted in the treated groups (26% more than the control) with respect to the initial number. Furthermore, at the time of harvest, honey storage in the treated hives was 17% higher than in the control hives. In addition, spore counts of both Nosema sp. and Varroa sp. foretica in treated hives were lower than in the control hives. These results with experimental hives would indicate that B. subtilis subsp. subtilis Mori2 favoured the performance of bees; firstly, because the micro-organism stimulated the queen's egg laying, translating into a higher number of bees and consequently more honey. Secondly, because it reduced the prevalence of two important bee diseases worldwide: nosemosis and varroosis.

First Report of a Predaceous Wasp Attacking Nymphs ofDiaphorinacitri(Hemiptera: Psyllidae), Vector of Hlb

Since 2008, a wasp species has been observed to predate nymphs of Diaphorina citri Kuwayama (Hemiptera: Psyllidae) (Fig. 1), the Asian citrus psyllid, one of the vectors of the bacterial patho gen Candidatus Liberibacter asiaticus, causal agent of the deadly citrus greening disease (Xuet al. 1998; Gamier & Bove 2000). The wasp species was identified as the Mexican honey wasp, Brachygastra mellifica (Say 1837) (Vespidae: Polistinae) by M. Buck. This wasp was first ob served attacking D. citri nymphs in 2008 in sweet orange, Citrus x sinensis (L.) Osbeck (Rutaceae), and lemon, Citrus x limon (L.) Burm. f. (Ruta ceae), groves, planted 3 to 5 yr ago in Rio Bravo, Tamaulipas, Mexico (25°56'39.12N, 98°07'3.9W, 28. 2 elev.). We have been observing B. mellifica since 2008 at Rio Bravo, and have found that its predatory activity is greatest during Jul through Sep when a high population of D. citri nymphs is present on new flush. B. mellifica are small ocial wasps (body length 7-9 mm), and are one of the few insect species, other than honey bees, that produce and store honey (Sugden & McAllen 1994). The species con

The effects of land use on honey bee (Apis mellifera) population density and colony strength parameters in the Eastern Cape, South Africa

Livestock farming in the Eastern Cape, South Africa is a common land use practice that has affected the biodiversity of plants and animals in the region negatively. Indigenous populations of wild honey bee (Apis mellifera) colonies also may suffer. Recently, farmers in the Eastern Cape have been converting their farms to game reserves as ecotourism attractions and nature conservation lands. Consequently, the goal of this research was to determine if land use habits (livestock farming and conversion to game reserves) in the Eastern Cape affect honey bee colony population density and colony strength parameters. A series of indices were developed to compare the relative population densities of colonies in two or more areas by counting the number of foraging bees and number of bee lines established at feeding stations. Wild colonies on farms and reserves were located and sampled to determine land use effects on colony strength parameters including total area of comb in the colony, the area of comb containing stored honey, pollen, and brood, adult bee population, weight per bee, and the colony nest cavity volume ratio. When viewed collectively, the data indicated that land use practices have affected honey bee nesting dynamics in the Eastern Cape. Trends in the data suggested that colonies nesting on the reserves may occur in greater densities than those nesting on livestock farms, though they do not appear to be healthier. Hopefully, this work will be continued since honey bee conservation in areas where they are native is crucial to the health of agriculture and whole ecosystems globally.

Lactobacillus johnsonii CRL1647, isolated from Apis mellifera L. bee-gut, exhibited a beneficial effect on honeybee colonies

Lactobacillus johnsonii CRL1647, isolated from the intestinal tract of a honeybee and selected due to its high lactic acid production, was assayed as a monoculture on bee colony performance. It was delivered to the bees on a one litre of 125 g/l sugar-cane syrup with a final concentration of 105 cfu/ml lactobacilli. The bees accepted the new nourishment, which was consumed within 24-48 h and was administered in two independent trials (every 14-15 days for 3 consecutive months in one case, and once a month for 13 consecutive months in the other). From late spring - early summer (2008) the photo-records and statistical analyses revealed significant differences in the open and the operculated brood areas in the treated group compared with the control. This stimulation was observed after the first administration of the lactobacilli and maintained throughout. Also, a higher number of bees were measured in the treated group (54%) and the control (18%) with respect to the initial bees' number. Furthermore, honey storage was higher, 40% and 19%, for the treated and control groups, respectively. From December 2008 to December 2009, a similar situation was observed even though, in this trial, the lactobacilli cells were administered once a month. The in vivo results of this study are promising and indicate that a L. johnsonii CRL1647 supplement to beehives favours mainly open and operculated brood areas, demonstrating a stronger stimulation of egg-laying and will become a natural product which will assist the beekeeper both in colony management and the creation of late nuclei and/or bee packages due to its beneficial effects in the beehive colony.

Storage-induced chemical changes in active components of honey de-regulate its antibacterial activity

To elucidate reasons for the observed variability in the antibacterial activity of honeys, we analysed a causal relationship between (a) honey floral sources and the activity and (b) the effect of honey storage on stability of compounds conferring this activity. Honeys from diverse floral sources were screened against Escherichia coli (ATCC 14948) and Bacillus subtilis (ATCC 6633) using the broth microdilution method. Among “active” honeys, 37% originated from buckwheat, 18% from clover and 12% from blueberry, indicating that these floral sources produced phytochemical(s) that inhibited bacterial growth. The stability of the putative phytochemical(s) was analysed in “active” honeys (MIC90 6.25% v/v) by measuring the activity every 3–6months for a period of 1–3years. A sharp decline in activity against both bacteria was observed in the first 3–6months of storage. The decline coincided with major changes in chemical composition of honeys which included a significant change in colour (p<0.0025), extremely significant change in concentration of UV-absorbing compounds (p<0. 0001) and appearance of melanoidins. While these changes reduced E. coli sensitivity to honey, it rendered B. subtilis completely insensitive. Thus, the data indicates that the presence of phytochemical(s) conferring the antibacterial activity is sensitive to storage. The de-regulation of the antibacterial activity with the concomitant appearance of melanoidins suggests that the active phytochemical components might be sequestered into melanoidin aggregates, losing their function.

Multiple mechanisms underlie displacement of solitary Hawaiian Hymenoptera by an invasive social wasp

Variation in invasion success may result from the divergent evolutionary histories of introduced species compared to those of native taxa. The vulnerability of native biotas to ecological disruption may be especially great on oceanic islands invaded by continental species with unique ecological traits. In part because Hawaii lacks native eusocial insects, social invaders may threaten endemic taxa that are ecologically similar but solitary. Using a combination of field manipulations, molecular analyses, physiological data, and behavioral assays, we identify the mechanisms underlying the displacement of two genera of native solitary Hymenoptera in Hawaii by a social continental invader, the western yellowjacket (Vespula pensylvanica). Experimental removal of V. pensylvanica colonies resulted in increased densities of native Hymenoptera. Endemic Hylaeus bees directly suffer through predation by yellowjackets, and perhaps as a consequence, avoid floral resources occupied by V. pensylvanica. Native Nesodynerus wasps also avoid V. pensylvanica but are negatively affected by yellowjackets not through predation, but through exploitative competition for caterpillar prey. Displacement of native solitary Hymenoptera may be heightened by the ability of V. pensylvanica to prey upon and scavenge honey bees and to rob their honey stores, resources unavailable to endemic bees and wasps because of their specialized niches. Our study provides a unique example of an ecologically generalized social invader that restructures native assemblages of solitary Hymenoptera by interacting with endemic taxa on multiple trophic levels.

Pollen sources for honeybees in Israel: Source, periods of shortage, and influence on population growth

The nutritional demands of honeybees are met by two plant-produced components: nectar and pollen, the contents of which vary among floral sources. In Israel, there is an extraordinary richness in plant species, and one of the dominant insect pollinators is the honeybee (Apis mellifera L.). July to February is characterized as a period of low flower abundance for local species in general and for bee forage plants in particular. In this study, we monitored the amount and number of pollen sources collected by honeybees, and where possible also identified the plant source of pollen, in four geographically distinct sites in Israel. We also assessed honeybee colonies (population level, sealed brood area, and pollen and honey stores) and studied the effect of pollen levels on population growth. Our results show that peak pollen-collection times differ according to site. The number of pollen sources from trapped pollen pellets varied during the year, between sites, and between colonies in the same site, and ranged between 5 and 20 plant species per sampling date per site. The most abundant pollen source in each sample comprised between 22 and 94% of the pollen pellets. There were only a few cases in which pollen was collected from fewer than five or more than nine plants in each colony's sample. Thus, colonies seem to specialize in only a small number of species of the available flora. Overall, in all sites, the daily amount of pollen collected was significantly correlated with sealed brood and pollen store areas.