Nest characteristics and recruitment behavior of absconding colonies of the African honey bee,Apis mellifera scutellata,in Africa

Absconding behavior was investigated in a naturally occurring population of honey bees in the Okavango River Delta, Botswana. Fifty percent of all colonies excavated in the field between October and December had abandoned the nest or were preparing for absconding, suggesting that an absconding season began in the Delta in October or November. However, the factors influencing absconding during this period were unclear, and there were no distinct differences in nest characteristics of the absconding and nonabsconding colonies. Waggle dance activity in observation colonies preparing for absconding was not used to preselect a specific nest site prior to departure. However, in two of the three colonies examined recruitment activity indicated the general direction of colony travel. The distances indicated by these dancers ranged between 6 and 16 km. Since these distances were three to four times greater than those communicated by dancers in nonabsconding colonies, workers from absconding colonies may sample potential forage or nest sites well outside their regular foraging range.     

Several workers lay eggs in the same brood cell in queenless honey bee (Apis mellifera) colonies

Queenless honey bee (Apis mellifera) colonies are often characterized by the presence of multiple eggs in brood cells. This is surprising because only one egg can be reared to maturity per cell. Moreover, worker honey bees cannot produce many eggs per day. There are several reasons that could explain the presence of multiple eggs in single cells: a) workers cannot control how many eggs they release; in this case we would expect all eggs to be from the same mother; b) excess eggs could be provided as food for the first larva to hatch in the absence of adequate brood care and this would again result in all eggs in one cell sharing the same mother; c) the number of cells available for oviposition may be limiting, obliging workers to lay eggs in cells that already contain eggs, resulting in eggs of mixed maternity. Here we show that the majority of brood cells in queenless colonies contain eggs from multiple mothers. Therefore our results suggest that the presence of multiple eggs in brood cells arises from a limitation on the number of suitable cells available for oviposition. Received 29 September 2008; revised 21 November 2008; accepted 24 November 2008.     

Waggle dance behavior associated with seasonal absconding in colonies of the African honey bee,Apis mellifera scutellata

Summary Waggle dance activity associated with seasonal absconding (migration) was investigated in two colonies of the African honey bee. Prior to absconding, waggle dances regularly communicated distances up to 10–20 km from the nests. However, compared to waggle dances observed during nonabsconding periods, those occurring prior to migration were less associated with food sources, occurred during periods of little or no flight activity, and exhibited great variability in the communication of distance by consecutive waggle runs of individual bees. It is therefore unlikely that migration dances communicated the locations of, or stimulated immediate recruitment for, specific foraging or nesting sites. Rather, the dances may have functioned to establish a general route of travel. The majority of migration dances observed were oriented in an easterly direction, and upon departure both colonies traveled towards the E-SE. The orientation of migration dances occurred independently of the directions communicated by waggle dances associated with past foraging success or the sampling of alternate foraging areas. Migration dance orientation may have been affected by prevailing wind directions, because during the migration period winds blew primarily from the east. However, it is unlikely that wind direction was the only factor influencing migration dance orientation. The lack of immediate flight activity associated with migration dance performance suggests the dances may have gradually prepared colonies for migratory movement by conveying a message to fly for a long, but unspecified distance in a certain direction. Waggle dances associated with migration may therefore function differently from those associated with foraging and nest site selection, which convey both the distance and direction to specific locations.     

Variation in worker response to honey bee (Apis mellifera L.) queen mandibular pheromone (Hymenoptera: Apidae)

Genetic and environmental influences on the worker honey bee retinue response to queen mandibular gland pheromone (QMP) were investigated. Worker progeny were reared from queens originating from four sources: Australia, New Zealand, and two locations in British Columbia, Canada (Simon Fraser University and Vancouver Island). Progeny from New Zealand queens responded significantly higher (P < 0.05) than progeny from Australia in a QMP retinue bioassay. Retinue response was not related to queen production of pheromone or colony environment, and the strain-dependent differences in retinue bioassay responses were maintained over a wide range of dosages. Selected high- and low-responding colonies were bioassayed over the course of 1 year. High-responding colonies contacted QMP lures more frequently than low-responding colonies (P < 0.05) throughout the year except in late summer. We conclude that there is a strong genetic component to QMP response by worker honey bees, as well as a seasonal effect on response.     

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.     

Survival of the mite Varroa jacobsoni Oud. (Mesostigmata: Varroidae) in broodless colonies of the honey bee Apis mellifera L. (Hymenoptera: Apidae)

Varroa mite free colonies of the honey bee Apis mellifera L. were artificially infested, with either parasitized bees or infested worker brood. Queens were kept in cages to provide broodless conditions during the experiment. Parasites that fell to the bottom of the hive were monitored at 3–4 days intervals for three months. An acaricide treatment was used to recover mites still alive after this time period. Survivorship at each interval was calculated and life table functions of the phoretic mite cohorts were obtained. Trends in survival of Varroa cohorts showed maximum lifespans ranging from 80 to 100 days. Life expectancy of these phoretic cohorts at the beginning of the experiment ranges between 19 to 41, with a mean of 31 days.     

The distribution of Paenibacillus larvae spores in adult bees and honey and larval mortality, following the addition of American foulbrood diseased brood or spore-contaminated honey in honey bee (Apis mellifera) colonies

Within colony transmission of Paenibacillus larvae spores was studied by giving spore-contaminated honey comb or comb containing 100 larvae killed by American foulbrood to five experimental colonies respectively. We registered the impact of the two treatments on P. larvae spore loads in adult bees and honey and on larval mortality by culturing for spores in samples of adult bees and honey, respectively, and by measuring larval survival. The results demonstrate a direct effect of treatment on spore levels in adult bees and honey as well as on larval mortality. Colonies treated with dead larvae showed immediate high spore levels in adult bee samples, while the colonies treated with contaminated honey showed a comparable spore load but the effect was delayed until the bees started to utilize the honey at the end of the flight season. During the winter there was a build up of spores in the adult bees, which may increase the risk for infection in spring. The results confirm that contaminated honey can act as an environmental reservoir of P. larvae spores and suggest that less spores may be needed in honey, compared to in diseased brood, to produce clinically diseased colonies. The spore load in adult bee samples was significantly related to larval mortality but the spore load of honey samples was not.     

啶虫脒对西方蜜蜂蜂王培育质量的影响

【目的】本实验旨在研究王台中残留啶虫脒对西方蜜蜂Apis mellifera蜂王培育质量的影响。【方法】通过融化蜂蜡并添加啶虫脒药液制作王台,使各王台中分别含4个不同剂量的啶虫脒(0, 10, 100和1 000 μg/kg蜂蜡)。同时,控制蜂王产卵6 h, 3 d后,将孵化为1日龄的幼虫分别移入各组王台中,并放入蜂群哺育。移虫后第3和6天分别统计各组王台中幼虫的接受率和封盖率,待蜂王出房时,计算其出房率,测定蜂王个体初生重、胸重和胸宽指标;采用实时荧光定量PCR(qPCR)技术测定蜂王卵巢中卵黄原蛋白基因(Vg)、储存蛋白基因(hex110和hex70b)的相对表达量。【结果】100 μg/kg蜂蜡和1 000μg/kg蜂蜡这两个啶虫脒剂量组西方蜜蜂蜂王的出房率都显著低于0 μg/kg蜂蜡和10 μg/kg蜂蜡剂量组,而0 μg/kg蜂蜡与10 μg/kg蜂蜡剂量组之间及100 μg/kg蜂蜡与1 000 μg/kg蜂蜡剂量组之间出房率 均差异不显著;这4个剂量组的王台幼虫接受率和封盖率以及蜂王的初生重、胸重和胸宽均无显著差异。qPCR结果显示,Vg基因的相对表达量随啶虫脒浓度的增加而下降,其中,1 000 μg/kg蜂蜡剂量组Vg基因的相对表达量显著低于10 μg/kg蜂蜡剂量组和0 μg/kg蜂蜡剂量组,其余各剂量组之间差异不显著;这4个剂量组之间hex110和hex70b基因的表达量差异不显著。【结论】西方蜜蜂王台中啶虫脒残留超过100 μg/kg蜂蜡剂量时,会对蜂王培育产生不利影响。     

Factors influencing seasonal absconding in colonies of the African honey bee,Apis mellifera scutellata

Summary This study investigated the effects of colony growth and development, food storage, foraging activity and weather on the migration behavior of African honey bees in the Okavango River Delta, Botswana. Four observation colonies were studied during the honey bee migration season (November–May), at which time the availability of blooming species was reduced. Two of the colonies (colonies 1 & 2) migrated during the study period, while the remaining two (colonies 3 & 4) did not. During the 4–6 weeks preceding the onset of migration preparations, colonies 1 & 2 exhibited increasing population sizes, high levels of brood production with low brood mortality, relatively large stores of food, and increasing mass. In contrast, the populations of colonies 3 & 4 did not increase, brood-rearing activity was erratic and lower, brood mortality was higher, food stores became depleted and colony mass declined. Both colonies 3 & 4 ceased rearing brood, and colony 3 died of starvation. Colony foraging activity was examined by monitoring waggle-dance activity 2–3 days each week. For 4–6 weeks before the onset of migration in colonies 1 & 2, daily foraging areas and mean daily foraging distances became increasingly large and variable. Colonies 3 & 4 exhibited foraging patterns similar to those observed for colonies 1 & 2 preceding migration. There was no clear association between 7 weather parameters examined and migration behavior. These data suggest that migration is influenced by an interaction of intra-colony demographics, food reserves and foraging patterns. Migration may be feasible only for those colonies that possess (1) a population of appropriate size and age structure to compensate for the natural attrition of older workers during the emigration process, and (2) sufficient food reserves for long-distance travel and the establishment of a new nest. Changing foraging patterns may reflect a deteriorating foraging environment, which may trigger the onset of migration preparations, provided that colony demographics and food reserves are conducive. Colonies that show decreased brood production, higher brood mortality and reduced food stores may be incapable of migrating, even when experiencing deteriorating foraging conditions. Rather, such colonies may have a greater chance of survival if they attempt to persist in a given area.     

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.     

Organization of the antennal lobe in the queen honey bee,Apis mellifera L. (Hymenoptera : Apidae)

Antennal afferent pathway topography was studied in the queen honey bee, Apis mellifera L. (Hymenoptera : Apidae) by staining with cobalt chloride applied directly to the cut antennal axons. Antennal lobe organization in the queen was compared with those in worker and drone bees. The organization is similar in queen and worker bees. For the first time in a female insect the possible existence of a macroglomerulus is shown, which may be involved in the processing of species-specific information. A comparative quantitative neuromorphological study of the glomeruli was performed between young queens (8-day old) and 1-yr-old queens. The mean volume of the glomeruli is 46% greater in the older queens.     

Impact of the introduced honey bee (Apis mellifera) (Hymenoptera: Apidae) on native bees: A review

Abstract Interspecific competition for a limited resource can result in the reduction of survival, growth and/or reproduction in one of the species involved. The introduced honey bee (Apis mellifera Linnaeus) is an example of a species that can compete with native bees for floral resources. Often, research into honey bee/native bee competition has focused on floral resource overlap, visitation rates or resource harvesting, and any negative interaction has been interpreted as a negative impact. Although this research can be valuable in indicating the potential for competition between honey bees and native bees, to determine if the long‐term survival of a native bee species is threatened, fecundity, survival or population density needs to be assessed. The present review evaluates research that has investigated all these measurements of honey bee/native bee competition and finds that many studies have problems with sample size, confounding factors or data interpretation. Guidelines for future research include increasing replication and using long‐term studies to investigate the impact of both commercial and feral honey bees.     

Colony migration in the tropical honey beeApis dorsata F. (Hymenoptera: Apidae)

Summary To obtain insights into the organization and adaptive significance of seasonal migration by colonies of the giant honey bee,Apis dorsata, we monitored the arrivals and departures of colonies in a rain forest habitat in northeastern Thailand, compared patterns of honey bee abundance with other measures of habitat variability, and observed the role of dance communication in organizing the migratory departure of a colony. Colonies arrived in the area during the end of the dry season, reproduced, and then departed early in the rainy season. During the immigration phase, early-arriving colonies stayed only temporarily, as if assessing habitat quality. Colonies departing after a long stay always left barren combs behind, suggesting that they had left in response to deteriorating resource quality. These observations support the idea that migration allows colonies to track seasonally varying resources in different regions. Our observations of a colony preparing for migration revealed that the dance language is involved in organizing the colony's departure, but that dancers signal only the direction to be taken, rather than, as in dances to feeding sites, both the direction and distance of a particular location.     

Super and half-sister discrimination by honey bee workers (Apis mellifera L.) in a trophallactic bioassay

Summary Kin recognition and nepotism between honeybee workers (Apis mellifera L.) was analysed in a trophallactic bio-assay. Donor workers were fed dyed sugar syrup and introduced into a recipient group consisting of 12 to 15 workers of the same colony. After allowing for 1 hour of trophallaxis, the distribution of the dyed food was analysed with spectrophotometry. The subfamily composition in the recipient group was varied such that the donor bees had to discriminate between workers of 2 to 7 different patrilines. Donor bees preferentially fed super sisters if few patrilines were present in the recipient group. However, preferential feeding was not observed if the recipient group consisted of workers of more than three subfamilies. Since the natural degree of polyandry causes intracolonial genetic variance to exceed the genetic variability in the experiments, nepotistic behaviour among workers may not reveal intranidal subfamily recognition in honeybees.     

Genetic pollution and number of matings in a black honey bee (Apis mellifera mellifera) population

Summary In the south-east of France, local honey bees possess only the B allele at the MDH locus, whereas the races which are usually imported into this area do not have this allele. The proportion of non-B genes in a sample of drones was used to measure the genetic pollution in the local population. Within the course of a breeding scheme of local bees, 99 queens, whose genotypes are BB, were naturally mated between April 25 and June 10, 1985 at la Tave (Gard, France). Twenty daughters-workers of each queen were analysed at the MDH locus. The frequency of the B allele in drones that mated with these queens is estimated by the proportion of workers with genotype BB and the genetic pollution by the cumulated frequency of the other alleles. The sampling variances of these frequencies involve a coefficient which is a function of the average number of drones mated with a queen. This latter parameter is estimated through the maximum likelihood method. In addition to the three well-known alleles, a rare allele (frequency=0.0055), possibly equivalent to the S1 allele described by Badino et al. (1983), has been found in three different colonies. Cumulating the frequencies of the non-B alleles results in an estimation of the genetic pollution equal to 0.0394 (±0.0071). This low value allows us to proceed to the next step of the selection project. The mean number of drones mated to a queen is 12.4 with a (10.4–19.3) confidence interval at the 90% level.     

Projection pattern of poreplate sensory neurones in honey bee worker,Apis mellifera L. (Hymenoptera : Apidae)

The projections of olfactory receptor cells of the poreplate sensilla were studied in the worker honey bee, Apis mellifera L. (Hymenoptera : Apidae) by filling single sensilla iontophoretically with cobalt chloride. Successful fillings of individual sensilla lead to staining of one to 22 sensory neurones. All stained receptor cell axons are uniglomerular. Seven fillings of poreplates from the 5th flagellar segment in different animals were compared to analyse the distribution patterns of the receptor cell axons in the antennal lobe. The sensory neurones of individual poreplates project to widely distributed glomeruli in the antennal lobe. The projection patterns of different poreplates are not the same, but may be overlapping.     

Spatial memory, navigation and dance behaviour in Apis mellifera

Navigation and dance communication in Apis mellifera have been extensively studied on the level of sensory processing, but the structure and content of the spatial memory underlying such phenomena have yet to be addressed. Here we survey new findings indicating that the memory used by bees to navigate within the range of their orientation flights is much more complex than hitherto thought. It appears to allow them to decide between at least two goals in the field, and to steer towards them over considerable distances. Two models concerning the structure of bees’ spatial memory are developed from new empirical evidence. The first one relies on the integration of at least two flight vectors, while the second assumes the existence of a ‘functional’ map based on the information available on-site. These findings also raise questions about the process of encoding and decoding information in the context of the waggle dance. We review published data and recent evidence indicating that memories of topographical features might also be involved in dance communication, and point out what needs to be addressed to elucidate the corresponding memory demands. The flight paths of recruited bees can now be traced by means of radar techniques, and thus tools are available to tackle these questions.