Choice of flowers by foraging honey bees (Apis mellifera): possible morphological cues

Abstract.

• 1 Honey bees foraging for nectar on lavender (Lavandula stoechas) chose inflorescences with more of their flowers open. The number of open flowers predicted whether an inflorescence was visited by bees, inspected but rejected, or ignored. Inflorescences chosen arbitrarily by observers had numbers of open flowers intermediate between those of visited and ignored inflorescences.
• 2 Differences in morphological characters between types of inflorescence correlated with nectar volume and sugar weight per flower so that visited inflorescences had a disproportionately greater volume of nectar and weight of sugar per flower and greater variance in nectar volume.
• 3 Although there were significant associations between nectar content and the morphological characters of inflorescences, discriminant function analysis revealed discrimination on the basis of morphology rather than nectar content.
• 4 Visited inflorescences tended to have smaller than average flowers but bees tended to probe the largest flowers on visited inflorescences.
• 5 Choice of flowers within inflorescences is explicable in terms of the relationship between flower size and nectar content.

     

蜜蜂花粉采集行为的调控机制

蜜蜂Apisspp.是一种社会性昆虫。社会性昆虫在对它们群体自身数量和巢穴环境的调节方面表现出明显的稳态特点,Emerson将这种稳态调节称为社会性稳态。蜂群中花粉的储存量就具有稳态的特点。蜂群的花粉采集行为是由蜂群对花粉的需要决定的。关于蜜蜂花粉采集行为的调控机制,目前的研究主要集中于是哪些信息以及蜂群是如何识别这些信息从而调控其采粉行为,主要形成了直接识别和间接识别2种假说。对这2种假说进行综述。     

Influence of immature queen honeybees (Apis mellifera) on queen rearing and foraging

ABSTRACT. Providing queenless colonies with five queen cells containing larvae or pupae diminished the number of queen cells and queen cell cups subsequently produced, but not as effectively as the provision of a mated laying queen. Immature queens were more effective than the mature queens in stimulating pollen collection, but were less effective in stimulating nectar collection.     

Influence of virgin queen honeybees (Apis mellifera) on queen rearing and foraging

ABSTRACT. Virgin queens are as effective as mated laying queens at inhibiting colonies from rearing queens but not from producing queen cell cups. Colonies without brood produce fewer queen cell cups than similar colonies that have brood. Colonies without queens forage much less and collect less pollen than with either a mated or virgin queen. Colonies with virgin queens forage as much as those with mated queens but collected less pollen.     

Spatial foraging patterns of the African honey bee,Apis mellifera scutellata

Recruitment patterns were investigated for the African honey bee in the Okavango River Delta, Botswana. The waggle dances of two observation colonies maintained in the field were monitored and used to construct maps of daily recruitment activity. These maps revealed that the African colonies frequently adjusted the allocation of recruits among food patches, recruited for 16–17 different food sites/day over areas of 55–80 km ² ,and concentrated the majority of recruitment within 1 km of the hives (median foraging distances for the two colonies were 295 and 563 m). In both colonies pollen foragers were more abundant than nectar foragers, and pollen sources indicated by waggle dancers were significantly closer to the hives than nectar sources. Compared to the recruitment patterns of temperate climate colonies, the African colonies had smaller recruitment areas, smaller mean recruitment distances, and a greater emphasis on pollen foraging. These differences may be related to the contrasting survival strategies followed by tropical-versus temperate-climate honey bees.     

Regulation of nectar collection in relation to honey storage levels by honey bees, Apis mellifera

Honey bees collect distinct nutrient sources in the form ofnectar (energy) and pollen (nitrogen). We investigated the effectof varying energy stores on nectar and pollen foraging. We foundno significant changes in nectar foraging in response to changesin honey storage levels within colonies. Individual foragersdid not vary activity rates or nectar load sizes in responseto changes in honey stores, and colonies did not increase nectarintake rates when honey stores within the hive were decreased.This result contrasts with pollen foraging behavior, which isextremely sensitive to colony state. Our data show that individualforaging decisions during nectar collection and colony regulationof nectar intake are distincdy different from pollen foraging.The behavior of honey bees illustrates that foraging strategy(and therefore foraging models) can incorporate multiple currencies,including both energy and protein intake.[Behav Ecol 7: 286–291(1996)]     

Impact of introduced honeybees, Apis mellifera, upon native bee communities in the Bonin (Ogasawara) Islands

The Bonin (Ogasawara) Islands are oceanic islands located in the northwest Pacific, and have ten native (nine endemic) bee species, all of which are nonsocial. The European honeybee (Apis mellifera), which was introduced to the islands for apiculture in the 1880s, became naturalized in a few islands shortly after introduction. To detect the impact of the honeybees upon native bee diversity, we analyzed pollen harvest by honeybees and surveyed the relative abundance of honeybees and native bees on flowers on several islands. Both hived and feral honeybee colonies were active throughout the year, harvesting pollen of both native and alien flowers and from both entomophilous and anemophilous flowers. Honeybees strongly depended on the alien plants, especially during winter to spring when native melittophilous flowers were rare. From June to November, honeybees exhaustively utilized native flowers, which had originally been utilized and pollinated by native bees. On Chichi and Haha Islands, where human disturbance of forests has been severe, both native and alien flowers were dominated by honeybees, and native bees were rare or extinct even in well-conserved forests. In contrast, on Ani Island and Haha's satellite islands where primary forests were well conserved and honeybees were still uncommon or absent, native bees remained dominant. These results suggest that competition for nectar and pollen of the native flowers between honeybees and native bees favors honeybees on the disturbed islands, which are thoroughly invaded by alien nectariferous, sometimes aggressive, weedy plants. Received: May 8, 1998 / Accepted: May 6, 1999     

转Bt-cry1Ah基因玉米花粉对意大利蜜蜂幼虫的影响

新型杀虫蛋白基因crylAh基因是中国农业科学院植物保护研究所从Bt菌株BT8中鉴定克隆的,其编码蛋白对鳞翅目害虫具有强毒力,尤其对亚洲玉米螟Ostriniafurnacalis（Guen6e）的毒力强于目前使用的crylA类基因。转crylAh基因抗虫玉米具有很好的应用前景。花粉是蜜蜂重要的食物来源,蜜蜂是转基因植物安全性评价的关键测试生物。因此,开展转crylAh基因玉米对蜜蜂的安全性研究很有必要。给意大利蜜蜂ApismelliferoligusticoSpirola蜂群中4-6日龄幼虫饲喂转基因玉米花粉、常规玉米花粉、杂花粉,哺育蜂饲喂为对照。转基因玉米花粉对意大利蜜蜂封盖率、出房率和发育历期没有显著影响。表明转crylAh基因玉米花粉对意大利蜜蜂幼虫的存活和发育没有不良影响。     

Comparison of contemporary mating patterns in continuous and fragmented Eucalyptus globulus native forests

While habitat fragmentation is a central issue in forest conservation studies in the face of broad-scale anthropogenic changes to the environment, its effects on contemporary mating patterns remain controversial. This is partly because of the inherent variation in mating patterns which may exist within species and the fact that few studies have replication at the landscape level. To study the effect of forest fragmentation on contemporary mating patterns, including effective pollen dispersal, we compared four native populations of the Australian forest tree, Eucalyptus globulus . We used six microsatellite markers to genotype 1289 open-pollinated offspring from paired fragmented and continuous populations on the island of Tasmania and in Victoria on mainland Australia. The mating patterns in the two continuous populations were similar, despite large differences in population density. In contrast, the two fragmented populations were variable and idiosyncratic in their mating patterns, particularly in their pollen dispersal kernels. The continuous populations showed relatively high outcrossing rates (86–89%) and low correlated paternity (0.03–0.06) compared with the fragmented populations (65–79% and 0.12–0.20 respectively). A greater proportion of trees contributed to reproduction in the fragmented ( de/d ≥ 0.5) compared with the continuous populations ( de/d  =   0.03–0.04). Despite significant inbreeding in the offspring of the fragmented populations, there was little evidence of loss of genetic diversity. It is argued that enhanced medium- and long-distance dispersal in fragmented landscapes may act to partly buffer the remnant populations from the negative effects of inbreeding and drift.     

Spatial foraging patterns and colony energy status in the African honey bee,Apis mellifera scutellata

The relationship between changes in foraging patterns (inferred from waggle dance activity) and colony energy status (inferred from brood rearing activity, food storage, and colony weight) was examined for the African honey bee during a period of relative resource abundance and resource dearth. When resources were more abundant mean foraging distances (about 400 m) and foraging areas (4–5 km²) were small, and colonies recruited to 12–19 different sites per day. Colony foraging ranges and sites visited increased slightly during the dearth period, yet foraging continued to be concentrated within less than 10 km². The degree to which fluctuations in foraging patterns were correlated with colony energy status varied with the availability of floral resources. During periods of relative forage abundance, increases in foraging range and number of sites visited were significantly correlated with increases in brood rearing and colony weight. In contrast, colonies examined during periods of resource dearth exhibited no correlations between foraging areas, foraging distances, and fluctuations in brood rearing, food storage, or colony weight. Thus, during dearth periods colonies may not be able to coordinate foraging patterns with changes in colony energy status.     

Flower visitation patterns of the coexisting honey bees Apis cerana japonica and Apis mellifera (Hymenoptera: Apidae)

We compared flower visitation patterns of two coexisting honey bees, Apis mellifera Linnaeus and Apis cerana japonica Radoszkowski, on 20 plant species, including three exotics, under natural conditions in Nara, Japan, from April to August 2012. We also measured flower color based on bee color vision (15 flower species), nectar volume (nine species) and nectar concentration (eight species). Flowers colored white, pink, red, purple and cream were classified as bee‐blue‐green, and yellow was classified as bee‐green. Apis cerana visited 14 plant species and A. mellifera visited 11. Although the two Apis species are similar in morphology, they visited different plants: in particular, A. cerana visited native plant species more often than did A. mellifera. Both A. mellifera and A. cerana visited not only nectariferous flowers but also those with no nectar. We also found different visitation patterns between A. cerana and A. mellifera: Apis cerana more often visited flowers with smaller color angle (bee‐blue‐green), lower chroma and higher brightness, and flowers secreting nectars of higher concentration and smaller volume than did A. mellifera.     

Nectar and Pollen Sources for Honeybee （Apis cerana cerana Fabr.） in Qinglan Mangrove Area, Hainan Island, China

In the present study, nectar and pollen sources for honeybee （Apls cerana cerana Fabr.） were studied in Qlnglan mangrove area, Hainan Island, China, based on microscopic analysis of honey and pollen load （corblcular and gut contents） from honeybees collected In October and November 2004. Qualitative and quantitative melittopalynologlcal analysis of the natural honey sample showed that the honey is of unlfloral type with Mimosa pudlca L. （Mlmosaceae） as the predominant （89.14%） source of nectar and pollen for A. cerana cerana In October. Members of Araceae are an Important minor （3%-15%） pollen type, whereas those of Arecaceae are a minor （〈3%） pollen type. Pollen grains of Nypa fruticans Wurmb., Rhlzophora spp., Excoecarla agallocha L., Lumnitzera spp., Brugulera spp., Kandella candel Druce, and Ceriops tagal （Perr.） C. B. Rob. are among the notable mangrove texa growing In Qinglan mangrove area recorded as minor taxa In the honey. The absolute pollen count （I.e. the number of pollen grains/10 g honey sample） suggests that the honey belongs to Group V （〉1 000 000）. Pollen analysis from the corblcular and gut contents of A. cerana cerana revealed the highest representation （95.60%） of members of Sonneratia spp. （Sonneratlaceae）, followed by Bruguiera spp. （Rhizophoraceae）, Euphorblaceae, Poaceae, Fabaceae, Arecaceae, Araceae, Anacardlaceae, and Rublaceae. Of these plants, those belonging to Sonneratla plants are the most Important nectar and pollen sources for A. cerana cerana and are frequently foraged and pollinated by these bees in November.     

Thermoregulation of foraging honeybees on flowering plants: seasonal variability and influence of radiative heat gain

1. During nectar and pollen foraging in a temperate climate, honeybees are exposed to a broad range of ambient temperatures, challenging their thermoregulatory ability. The body temperature that the bees exhibit results from endothermic heat production, exogenous heat gain from solar radiation, and heat loss. In addition to profitability of foraging, season was suggested to have a considerable influence on thermoregulation. To assess the relative importance of these factors, the thermoregulatory behaviour of foragers on 33 flowering plants in dependence on season and environmental factors was investigated.2. The bees (Apis mellifera carnica Pollman) were always endothermic. On average, the thorax surface temperature (T(th)) was regulated at a high and rather constant level over a broad range of ambient temperatures (T(th) = 33.7-35.7°C, T(a) = 10-27°C). However, at a certain T(a), T(th) showed a strong variation, depending on the plants from which the bees were foraging. At warmer conditions (T(a) = 27-32°C) the T(th) increased nearly linearly with T(a) to a maximal average level of 42.6 °C. The thorax temperature excess decreased strongly with increasing T(a) (T(th)-T(a) = 21.6 - 3.6°C).3. The bees used the heat gain from solar radiation to elevate the temperature excess of thorax, head, and abdomen. Seasonal dependance was reflected in a 2.7 °C higher mean T(th) in the spring than in the summer. An anova revealed that season had the greatest effect on T(th), followed by T(a) and radiation.4. It was presumed the foragers' motivational status to be the main factor responsible for the variation of T(th) between seasons and different plants.     

Cape honeybees, Apis mellifera capensis, police worker-laid eggs despite the absence of relatedness benefits

In the Cape honeybee, Apis mellifera capensis, workers lay diploid(female) eggs via thelytoky. In other A. mellifera subspecies,workers lay haploid (male) eggs via arrhenotoky. When thelytokousworker reproduction occurs, worker policing has no relatednessbenefit because workers are equally related to their sisterworkers' clonal offspring and their mother queen's female offspring.We studied worker policing in A. m. capensis and in the arrhenotokousAfrican honeybee A. m. scutellata by quantifying the removalrates of worker-laid and queen-laid eggs. Discriminator coloniesof both subspecies policed worker-laid eggs of both their ownand the other subspecies. The occurrence of worker policing,despite the lack of relatedness benefit, in A. m. capensis stronglysuggests that worker reproduction is costly to the colony andthat policing is maintained because it enhances colony efficiency.In addition, because both subspecies policed each others eggs,it is probable that the mechanism used in thelytokous A. m.capensis to discriminate between queen-laid and worker-laideggs is the same as in arrhenotokous A. m. scutellata.     

The influence of hybridization between African and European honeybees, Apis mellifera, on asymmetries in wing size and shape

Abstract We examined the possible role of hybridization in the invasion process of the African honeybee by testing two hypotheses regarding fluctuating asymmetry (FA), a measure of developmental stability, in wing characteristics: (1) FA should be higher in hybrid versus parental genotypes of African and European races; (2) FA should be lower in African bees compared to hybrid and European workers. Parental and reciprocal hybrid worker genotypes were cross fostered in common-hive rearing environments. We did not find greater FA for wing size and shape in the hybrids compared to both parental types. However, we did find significantly lower FA of shape in the African workers compared to the European and hybrid workers, suggesting that European bees and their hybrids may have compromised fitness relative to African bees. We also found that the two hybrid genotypes significantly differed in overall wing size and shape. If these differences affect wing aerodynamics, then the paternity of hybrids may influence worker performance and could potentially contribute to the loss of European matrilines. Hybridization had few consistent effects on directional asymmetry for wing size and shape. Genotypic factors played a far greater role in determining the effect of hybridization on wing morphology than did differences in rearing environment. Thus, African bees may have lower FA for wing shape (and by inference greater developmental stability) relative to European and hybrid workers, which may contribute to the ability of African bees to displace European honeybee races in invaded regions.     

Seasonal patterns of foraging activity in colonies of the African honey bee,Apis mellifera scutellata,in Africa

Summary Seasonal foraging patterns were investigated using six observation colonies maintained in the Okavango Delta, Botswana. Pollen collection, flight from the hive, and recruitment for pollen and nectar sources occurred throughout the 11 months of the study. However, the distribution of foraging activity throughout the day changed seasonally. Colonies emphasized recruitment for pollen sites throughout most of the year. Brood production occurred in all months except May, and there was a significant, positive correlation between the proportion of recruitment activity devoted to pollen sources and the amount of brood comb in the colonies. The seasonal foraging patterns ofscutellata in the Okavango were similar to those of Africanized honey bees in the neotropics. The extended foraging season and emphasis on pollen collection may be associated with the high swarming rates and migrational movements of tropical honey bees.     

The relationship between the abundances of bumblebees and honeybees in a native habitat

Abstract. 1. The western honeybee, Apis mellifera, has been introduced to many parts of the world and is sometimes purported to be detrimental to native bees because it reduces their food base. It is seldom viewed in this light in Europe; however, when beekeepers maintain very high bee densities, the species could also be displacing insects in its native European range by reducing the resource base. 2. In England, populations of bumblebees (Bombus Latr. Hym.) have been decreasing both in terms of diversity and abundance, mainly because of a loss of habitat resulting from agricultural intensification. The impact of competition from other flower feeders is largely unknown. 3. Nineteen dry lowland heaths in southern England were sampled once for honeybees and bumblebees. Honeybee abundance varied from 4 to 81 bees per 100 m² (mean = 30.89, median = 23), whereas bumblebees varied from 2 to 17 individuals per 100 m² (mean = 8.26, median = 7), belonging to between one and five species. There was a negative association between honeybee and bumblebee abundance but there was no apparent relationship between honeybee abundance and bumblebee diversity. 4. The Bray–Curtis coefficient was used to compare the similarity in honeybee and bumblebee floral host breadth at these 19 sites. The coefficient was negatively associated with honeybee abundance: thus where honeybees were most abundant, bumblebees were fewer and/or foraged on different flower species. 5. Foraging host breadth was also examined at four heathlands over a field season (April to September). No association between honeybee abundance and foraging host breadth was found for short‐tongued bees, although there was some evidence for a change in floral host breadth for long‐tongued bees. 6. It is concluded that the impact of honeybees on bumblebees is complex. Although competition between the two species cannot be ruled out, it is perhaps equally likely that bumblebees decline in response to other factors, and that honeybees move independently of this decline.     

Impacts of hive honeybees on Tasmanian leatherwood Eucryphia lucida Labill. (Eucryphiaceae)

Despite honeybees (Apis mellifera L.) occurring as a feral and commercially managed species in many parts of Australia, the effects of honeybees on native Australian ecosystems are poorly understood. We examined the impacts of honeybee apiaries on Tasmanian Leatherwood Eucryphia lucida Labill. (Eucryphiaceae) by comparing commercial apiary sites with control sites >2 km from the nearest apiary. Feral honeybees were common at control sites (73% of honeybees feral) but were scarce at apiary sites (2%), and hive honeybees appeared to be competitively displacing feral honeybees near apiaries. Visit rates by native insects appeared to be un‐affected by the increased numbers of hive honeybees near apiaries. Standing crops of nectar sugar were significantly depressed at apiary sites. Pollen was rapidly removed from flowers at apiary sites resulting in full separation of the male and female flower‐phases (flowers completely dichogamous). In contrast, at control sites, pollen tended to remain in flowers into the female phase (flowers partially dichogamous). There was no difference in the total number of pollen grains deposited on stigmas or in percentage seed set among apiary and control sites. However, fruit set was elevated at apiary sites, possibly owing to reduced autonomous (within‐flower) selfing. Our study indicated that honeybees significantly reduce floral resources (nectar and pollen) around apiaries, although any competitive effects on native insects may have been obscured by large variation in the abundance of native insects among experimental sites.