Waggle dances in absconding colonies of the red dwarf honeybee, Apis florea

The directional information encoded in the waggle dances of absconding colonies of Apis florea shows how different sites are advertised during decision-making. Colonies of A. florea were observed from the inception of absconding until the swarm settled at a new nest site. The number of waggle dancers at the beginning of the absconding sequence was low, gradually increased and then declined shortly before liftoff. During the last 2 to 0.5?h before liftoff, the dances still indicated different directions. This significantly decreased in the last 0.5?h until only one or two dance directions were being advertised. All colonies reached a near consensus in the last 20 dances before liftoff. The swarm flight path is meandering so the actual distance flown is about twice that indicated by the dances. During the last 3?min the waggle dance in most colonies showed nest target angles that were closely clustered indicating that the final directions advertised were close to the chosen target site. In all absconding/migratory species of honeybees thus far studied, there is a special dance associated with absconding that appears not to select specific destinations but rather a particular direction in search of a new nesting area.     

Experimental infection of red dwarf honeybee,Apis florea,with Nosema ceranae

This research is the first record of the infection of Apis florea by Nosema ceranae, a newly identified pathogen of honeybee in Thailand which was initially isolated from A. florea workers. Each Nosema free-bee was fed 2 μl of 50% (w/v) sucrose solution containing 0, 10,000 20,000 or 40,000 Nosema spores/bee. The survival rates of treated bees were significantly lower compared to control bees. Infectivity was not statistically different among the three spore concentrations, whereas no infection was found in control bees. Protein content of control bee hypopharyngeal glands 14 days post inoculation (p.i) was significantly higher (21.47 ± 0.17 mg/bee) compared to all treatments. The infection ratio of bees treated with 40,000 spores/bee increased with time after inoculation. These results suggest that N. ceranae has a significant negative effect on honeybee hypopharyngeal gland protein production and contributes to their shortened life span.     

Worker piping triggers hissing for coordinated colony defence in the dwarf honeybee Apis florea

Defending a large social insect colony containing several thousands of workers requires the simultaneous action of many individuals. Ideally this action involves communication between the workers, enabling coordinated action and a fast response. The Asian dwarf honeybee, Apis florea, is a small honeybee with an open nesting habit and a comparatively small colony size, features that leave them particularly exposed to predators. We describe here a novel defence response of these bees in which the emission of an initial warning signal from one individual ("piping") is followed 0.3 to 0.7 seconds later by a general response from a large number of bees ("hissing"). Piping is audible to the human ear, with a fundamental frequency of 384 +/- 31Hz and lasting for 0.82 +/- 0.35 seconds. Hissing is a broad band, noisy signal, clearly audible to the human observer and produced by slight but visible movements of the bees' wings. Hissing begins in individuals close to the piping bee, spreads rapidly to neighbours and results in an impressive coordinated crescendo occasionally involving the entire colony. Piping and hissing are accompanied by a marked decrease, or even cessation, of worker activities such as forager dancing and departures from the colony. We show that whereas hissing of the colony can be elicited without piping, the sequential and correlated piping and hissing response is specific to the presence of potential predators close to the colony. We suggest that the combined audio-visual effect of the hissing might deter small predators, while the cessation of flight activity could decrease the risk of predation by birds and insects which prey selectively on flying bees.     

云南地区小蜜蜂的饲养方法

为了小蜜蜂Apis florea资源的利用和保护,本论文对其饲养方法及生物学特性进行了研究。在云南省蒙自市,收集野生小蜜蜂8群,对其筑巢、蜂蜜生产、蜂群越冬等饲养方法进行研究,观察并记录饲养过程中蜂群生物学特性。辅助蜂群筑巢过程中,支撑巢脾的树枝距离地面高度在0.6-1.0 m,蜂群较稳定,不易弃巢;利用"巢脾分区切割"的方法生产蜂蜜可以提高产量,减少蜂群分蜂次数;模拟野外筑巢环境,用塑料框和稻草包装,置于日光室的网室内,可有效辅助蜂群越冬。通过对小蜜蜂饲养方法的探索,明确了云南地区小蜜蜂饲养过程中的筑巢高度及科学合理的蜂蜜生产、蜂群越冬方法,为深入研究该种传粉蜂资源的利用与保护提供了重要的参考依据。     

Deciding on the wing: in-flight decision making and search space sampling in the red dwarf honeybee Apis florea

During reproductive swarming and seasonal migration, a honeybee swarm needs to locate and move to a new, suitable nest site. While the nest-site selection process in cavity-nesting species such as the European honeybee Apis mellifera is very precise with the swarm carefully selecting a single site, open-nesting species, such as Apis florea, lack such precision. These differences in precision in the nest-site selection process are thought to arise from the differing nest-site requirements of open- and cavity-nesting species. While A. florea can nest on almost any tree, A. mellifera is constrained by the scarcity of suitable nest sites. Here we show that imprecision in the nest-site selection process allows swarms to quickly reach a decision when many nest sites are available. In contrast, a very precise nest-site selection process slows down the decision-making process when nest sites are abundant.     

Similar but not the same: insights into the evolutionary history of paralogous sex-determining genes of the dwarf honey bee Apis florea

Studying the fate of duplicated genes provides informative insight into the evolutionary plasticity of biological pathways to which they belong. In the paralogous sex-determining genes complementary sex determiner (csd) and feminizer (fem) of honey bee species (genus Apis), only heterozygous csd initiates female development. Here, the full-length coding sequences of the genes csd and fem of the phylogenetically basal dwarf honey bee Apis florea are characterized. Compared with other Apis species, remarkable evolutionary changes in the formation and localization of a protein-interacting (coiled-coil) motif and in the amino acids coding for the csd characteristic hypervariable region (HVR) are observed. Furthermore, functionally different csd alleles were isolated as genomic fragments from a random population sample. In the predicted potential specifying domain (PSD), a high ratio of π_N/π_S=1.6 indicated positive selection, whereas signs of balancing selection, commonly found in other Apis species, are missing. Low nucleotide diversity on synonymous and genome-wide, non-coding sites as well as site frequency analyses indicated a strong impact of genetic drift in A. florea, likely linked to its biology. Along the evolutionary trajectory of ~30 million years of csd evolution, episodic diversifying selection seems to have acted differently among distinct Apis branches. Consistently low amino-acid differences within the PSD among pairs of functional heterozygous csd alleles indicate that the HVR is the most important region for determining allele specificity. We propose that in the early history of the lineage-specific fem duplication giving rise to csd in Apis, A. florea csd stands as a remarkable example for the plasticity of initial sex-determining signals.     

Worker reproductive parasitism in naturally orphaned colonies of the Asian red dwarf honey bee, Apis florea

The truce between honey bee (Apis spp.) workers over reproduction is broken in the absence of their queen. Queenright workers generally abstain from personal reproduction, raising only the queen’s offspring. Queenless workers activate their ovaries, produce eggs, and reduce the rate at which they destroy worker-laid eggs, so that some eggs are reared to maturity. Reduced policing of worker-laid eggs renders queenless nests vulnerable to worker reproductive parasitism (WRP), and may result in the colony raising eggs of unrelated (non-natal) workers that parasitize it. Queenless colonies of A. florea are heavily parasitized with the eggs of non-natal workers. However, queenless colonies often abscond upon disturbance and build a small comb in which to rear their own male offspring. We investigated three naturally occurring orphaned colonies to determine if they are also parasitized. We show that WRP is present in orphaned colonies, and non-natal workers have significantly higher rates of ovary activation than natal workers. In contrast to experimentally manipulated colonies, in our samples, natal and non-natal workers had statistically equal reproductive success, but this may have been due to the small number of non-natals present.     

Interspecific and conspecific colony mergers in the dwarf honey bees Apis andreniformis and A. florea

The dwarf honey bees Apis florea and A. andreniformis are sympatric in southeast Asia. We translocated eight A. florea colonies and four A. andreniformis colonies to an orchard near Sai Yoke, Thailand. After 2 days, we dequeened half of the colonies. Microsatellite genotyping showed that a queenless A. florea colony merged with a queenright A. florea colony, and a queenless A. andreniformis colony merged with a queenright A. florea colony. The inter-specific merger in particular shows that colonies can combine without direct kin benefits, and that colony mergers probably arise through strong queen attraction.     

csd alleles in the red dwarf honey bee (Apis florea,Hymenoptera: Apidae) show exceptionally high nucleotide diversity

Abstract The single locus complementary sex determination (sl‐csd) gene is the primary gene determining the gender of honey bees (Apis spp.). While the csd gene has been well studied in the Western honey bee (Apis mellifera), and comparable data exist in both the Eastern honey bee (Apis cerana) and the giant honey bee (Apis dorsata), no studies have been conducted in the red dwarf honey bee, Apis florea. In this study we cloned the genomic region 3 of the A. florea csd gene from 60 workers, and identified 12 csd alleles. Analysis showed that similar to A. mellifera, region 3 of the csd gene contains a RS domain at the N terminal, a proline‐rich domain at the C terminal, and a hypervariable region in the middle. However, the A. florea csd gene possessed a much higher level of nucleotide diversity, compared to A. mellifera, A. cerana and Apis dorsata. We also show that similar to the other three Apis species, in A. florea, nonsynonymous mutations in the csd gene are selectively favored in young alleles.     

Lateralization of olfaction in the honeybee Apis mellifera

Lateralization of function is a well-known phenomenon in humans. The two hemispheres of the human brain are functionally specialized such that certain cognitive skills, such as language or musical ability, conspecific recognition, and even emotional responses, are mediated by one hemisphere more than the other [1, 2]. Studies over the past 30 years suggest that lateralization occurs in other vertebrate species as well [3-11]. In general, lateralization is observed in different sensory modalities in humans as well as vertebrates, and there are interesting parallels (reviewed in [12]). However, little is known about functional asymmetry in invertebrates [13, 14] and there is only one investigation in insects [15]. Here we show, for the first time, that the honeybee Apis mellifera displays a clear laterality in responding to learned odors. By training honeybees on two different versions of the well-known proboscis extension reflex (PER) paradigm [16, 17], we demonstrate that bees respond to odors better when they are trained through their right antenna. To our knowledge, this is the first demonstration of asymmetrical learning performance in an insect.     

Histomorphological study on embryogenesis of the honeybee Apis cerana

As important pollination species, honeybees play substantial impacts on the balance of global ecosystem, including two best-known honeybees Apis mellifera and Apis cerana. Embryogenesis is a fundamental stage of honeybee development and plays important roles in supporting the whole-life developmental process. However, few studies were reported on honeybee embryonic morphology using egg section, possibly due to the fragility of honeybee eggs and the difficulty of making embryonic sections. In this study, we reported a simply equipped method of frozen sectioning and PI (propidium iodide) staining to show the inner structure and cell distribution of A. cerena embryos at the different embryonic developmental stages. We found that the stages of A. cerena embryogenesis could also be typically classified into ten developmental stages, which are similar with the sister honeybee species, A. mellifera. To be noted, besides the cell distribution in the whole egg, we clearly observed the migration route of embryonic cells during the early embryonic development in A. cerena. This study provides a new insight into the whole process of honeybee embryogenesis from the perspective of egg sectioning, a histological basis for genetic manipulation using A. cerena eggs, and a reference method for egg sectioning for other insect species.     

Comparison of physicochemical properties and effects of heating regimes on stored Apis mellifera and Apis florea honey

Many of the components, which render honey its specific aroma, flavor, and biological activity, are unstable over time and thermolabile. This study was aimed to compare the chemical composition, effect of heating as well as the time of heat exposure, and storage period on the quality of honey samples from Apis mellifera (A.m.) and Apis florea (A.f.). Methods of the Association of the Official Analytical Chemists (AOAC) were used in this study. The mean values for both A.m. and A.f. honeys were, respectively: moisture (18.5, 13.7%); glucose (35.2, 36.3%); fructose (33.7, 33.8%); sucrose (7.3, 2.9%); invert sugar (68.9, 70.4%); ash (0.26, 1.1%); acidity (51.8, 98.4 meq/kg); pH (3.6, 4.4) and Hydroxy methyl furfural (HMF) (3.78, 3.17 mg/100 g). Honey from A. florea contained less moisture, have higher acidity and ash contents than A. mellifera honey. Significant alterations (P < 0.05) in glucose, fructose, sucrose, and acidity were noticed after six months. Honeys exposed to heating for 15 and 30 min at 50 and 80 °C have shown increased thermo-generated HMF after 15, 30, and 45 days. HMF reached 16.30 ± 1.1 in A. mellifera and 7.41 ± 1.4 mg/100 g in A. florea honeys that exposed for 30 min at 80 °C. Honey from A. florea showed more heat tolerance to thermo-generation of HMF than honey from A. mellifera.     

Lipophorin of the larval honeybee, Apis mellifera L

Most insects have a major lipoprotein species in the blood (hemolymph) that serves to transport fat from the midgut to the storage depots in fat body cells and from the fat body to peripheral tissues. The generic name lipophorin is used for this lipoprotein. In larvae of the honeybee, Apis mellifera, a lipophorin has been found with properties that correlate well with those of the only other lipophorin reported for an immature insect, that of the tobacco hornworm, Manduca sexta. The honeybee lipophorin (Mr = 530,000) has a density of 1.13 g/ml, contains approximately 41% lipid and 59% protein, and contains two apoproteins, apoLp-I, Mr = 250,000 and apoLp-II, Mr = 80,000, both of which are glycosylated. The lipids consist predominantly of polar lipids, of which phospholipids and diacylglycerols represent 60% of the total. When the intact lipophorin is treated with trypsin, apoLp-I is rapidly proteolyzed, while apoLp-II is resistant, indicating a difference in exposure of the two apoproteins to the aqueous environment. Honeybee apoLp-II cross-reacts with antibodies to M. sexta apoLp-II, but not to anti-M. sexta apoLp-I. No cross-reactivity of honeybee apoLp-I to anti-M. sexta apoLp-I was observed.     

Molecular characterization of hemoglobin from the honeybee Apis mellifera

Due to the prevailing importance of the tracheal system for insect respiration, hemoglobins had been considered rare exceptions in this arthropod subphylum. Here we report the identification, cloning and expression analysis of a true hemoglobin gene in the honeybee Apis mellifera (Hymenoptera). The deduced amino acid sequence covers 171 residues (19.5kDa) and harbors all globin-typical features, including the proximal and the distal histidines. The protein has no signal peptide for transmembrane transport and was predicted to localize in the cytoplasm. The honeybee hemoglobin gene shows an ancient structure, with introns in positions B12.2 and G7.0, while most other insect globins have divergent intron positions. In situ hybridization studies showed that hemoglobin expression in the honeybee is mainly associated with the tracheal system. We also observe hemoglobin expression in the Malpighi tubes and testis. We further demonstrated that hemoglobins occur in other insect orders (Hemiptera, Coleoptera, Lepidoptera), suggesting that such genes belong to the standard repertoire of an insect genome. Phylogenetic analyses show that globins evolved along with the accepted insect systematics, with a remarkable diversification within the Diptera. Although insect hemoglobins may be in fact involved in oxygen metabolism, it remains uncertain whether they carry out a myoglobin-like function in oxygen storage and delivery.     

The seminal fluid proteome of the honeybee Apis mellifera

Ejaculates contain sperm but also seminal fluid, which is increasingly recognized to be of central importance for reproductive success. However, a detailed biochemical composition and physiological understanding of seminal fluid is still elusive. We have used MS to identify the 57 most abundant proteins within the ejaculated seminal fluid of the honeybee Apis mellifera. Their amino acid sequences revealed the presence of diverse functional categories of enzymes, regulators and structural proteins. A number have known or predicted roles in maintaining sperm viability, protecting sperm from microbial infections or interacting with the physiology of the female. A range of putative glycoproteins or glycosylation enzymes were detected among the 57, subsequent fluorescent staining of glycolysation revealed several prominant glycoproteins in seminal fluid, while no glycoproteins were detected in sperm samples. Many of the abundant proteins that accumulate in the seminal fluid did not contain predictable tags for secretion for the cell. Comparison of the honeybee seminal fluid proteins with Drosophila seminal fluid proteins (including secreted accessory gland proteins known as ACPs), and with the human seminal fluid proteome revealed the bee protein set contains a range of newly identified seminal fluid proteins and we noted more similarity of the bee protein set with the current human seminal fluid protein set than with the known Drosophila seminal fluid proteins. The honeybee seminal fluid proteome thus represents an important addition to available data for comparative studies of seminal fluid proteomes in insects.     

引入西方蜜蜂对中蜂的危害及生态影响

作者阐述自1896年中国引进西方蜜蜂Apis melliferaL.的优良品种如意大利蜂Apis mellifera ligusticaSpinola和喀尼阿兰蜂Apis mellifera Carnica Pollmann以来,使当地的东方蜜蜂Apis cerana F.受到严重危害,其分布区域缩小75%以上,种群数量减少80%以上。使山林植物授粉总量减少,导致植物多样性减少。文中提出: 建立自然保护区保存本地蜜蜂遗传特性,和采用基因转移等技术,培育具有西方蜜蜂优良生产性能的中蜂新品种,逐步恢复中蜂的种群数量。     

Studies on the possible competition for pollen between the honey bee, Apis mellifera sudanensis, and the imported dwarf honey bee Apis florea (Hym., Apidae) in North-Khartoum (Sudan)

Abstract:   Based on identification of collected pollen, in the area of North Khartoum, 21 plant genera (ca. 21 spp.) proved to be the main pollen sources for the honey bee Apis mellifera sudanensis . The imported dwarf honey bee Apis florea exploited 11 of these. The main pollen flow in the study area occurred between early December and late March. This is reflected by the amount of pollen collected by colonies of A. mellifera sudanensis . In spite of observations conducted soon after the introduction of A. florea , which gave hints of competition between the two bee species, further studies showed that A. mellifera sudanensis and A. florea do seem to coexist. This coexistence is based on different daily rhythms of pollen collection. A. mellifera collected pollen of Acacia seyal , date palm, and onions early in the morning (and partly in the late afternoon), while A. florea started pollen collection mostly later in the morning and ended it earlier in the afternoon. But in contrast to A. mellifera, A. florea was collecting pollen all day without interruption, even at very high air temperatures. Niche overlap (concerning the times of visits to flowers) between the two bee species was very low in date palms, and of medium importance in Acacia seyal . But it is remarkable that in total, A. florea is always present in higher numbers than A. mellifera sudanensis , on flowers. The significance of the introduction of A. florea to Sudan for pollination is discussed.     

Modelling the subgenual organ of the honeybee, Apis mellifera

In a recent study on the honeybee (Apis mellifera), the subgenual organ was observed moving inside the leg during sinusoidal vibrations of the leg (Kilpinen and Storm 1997). The subgenual organ of the honeybee is suspended in a haemolymph channel in the tibia of each leg. When the leg accelerates, the inertia causes the haemolymph and the subgenual organ to lag behind the movement of the rest of the leg. To elucidate the biophysics of the subgenual organ system of the honeybee, two mathematical models to simulate the experimentally observed mechanical response are considered. The models are a classical mass-spring model and a newly developed tube model consisting of an open-ended, fluid-filled tube occluded by an elastic structure midway. Both models suggest that the subgenual organ included in the haemolymph channel resembles that of an overdamped system. In resembling the biophysics of the subgenual organ system in the honeybee, we consider the tube model to be the better of the two because it simulates a mechanical response which complies best with the experimental data, and the physical parameters in the model can be related to the␣constituent parts of the subgenual organ included in the haemolymph channel. Received: 25 July 1997 / Accepted in revised form: 8 December 1997