Pollen analysis of Apis dorsata Fabricius honeys in Bankura and Paschim Medinipur districts,West Bengal

One-hundred-and-five species corresponding to 38 families were identified through pollen analyses of 53 Apis dorsata honeys collected from Bankura and Paschim Medinipur districts, West Bengal. The families most frequently encountered were Fabaceae, Arecaceae, Asteraceae and Myrtaceae. Fabaceae had the greatest representation in number of pollen types (18 types), followed by Asteraceae (nine types), Cucurbitaceae (seven types), Lamiaceae and Myrtaceae (each with six types) and Malvaceae and Rutaceae (each with five types). Most of the honey samples correspond to class I. The presence of dominant pollen was detected in 18 samples. The predominant pollen types were Borassus flabellifer, Sesamum indicum (during summer), Eucalyptus globulus (during late autumn), Brassica nigra, Eucalyptus globulus (during winter) and Borassus flabellifer and Lannea coromandelica (during spring). The unifloral honeys obtained mostly during late autumn and winter were dominated by Eucalyptus globulus type. In monsoon and autumn unifloral honeys containing predominant pollen types (> 45%) were not found. However, according to frequency distribution the pollen types represented as very frequent were Peltophorum pterocarpum, Tridax procumbens (in monsoon) and Acacia auriculiformis, Cocos nucifera, Eucalyptus globulus, Tridax procumbens and Ziziphus mauritiana (in autumn). The seasonal diversity of pollen types obtained was at a maximum during spring (36 types) and minimum during late autumn (14 types). Seasonal variation in the number of pollen types per sample range from 5.86 ± 1.87 (during late autumn) to 6.86 ± 1.95 (during autumn) and exhibit low correlation (r = 0.31) with floral diversity. The diversity of pollen types per unifloral honey sample remains lower than multifloral honeys.     

Migrating Giant Honey Bees (Apis dorsata) Congregate Annually at Stopover Site in Thailand

Giant honey bees (Apis dorsata) of southern Asia are vital honey producers and pollinators of cultivated crops and wild plants. They are known to migrate seasonally up to 200 km. It has been assumed their migrations occur stepwise, with stops for rest and foraging, but bivouacking bees have rarely been seen by scientists. Here I report discovery of a site in northern Thailand where bivouacs appeared in large congregations during the wet seasons of 2009 and 2010. The bivouac congregation stopover site is a small mango orchard along the Pai River. Bivouacs rested in branches of mango and other tree species in the immediate vicinity. Departures were preceded by dances indicating approximate direction and apparently, distance of flights. Such consistent stopover sites likely occur throughout southern Asia and may support critical, vulnerable stages in the life history of giant honey bees that must be conserved for populations of the species to survive.     

Genetic Differentiation of the Giant Honey Bee (Apis dorsata) in Thailand Analyzed by Mitochondrial Genes and Microsatellites

Genetic diversity and population differentiation of the giant honey bee (Apis dorsata) in Thailand were examined. Six PCR-RFLP mitotypes were generated from digestion of the COI-COII, Cytb-tRNA^ser, ATPase6-8, and lrRNA genes with Dra I and Hin fI. Low genetic diversity (h=0.074, π=0.032%) and a lack of genetic population differentiation between A. dorsata originating from geographically different regions were observed from mtDNA polymorphisms (P > 0.05). In contrast, microsatellite (A14, A24, and A88) polymorphisms revealed a relatively high level of genetic diversity in A. dorsata (H _o=0.68–0.74, average number of alleles per locus=6.0–9.0). Both A24 and A88 indicated significant population differentiation between bees from the north-to-central region (north, northeast, and central regions), peninsular Thailand, and Samui Island.     

The sex determination gene shows no founder effect in the giant honey bee, Apis dorsata

Background

All honey bee species (Apis spp) share the same sex determination mechanism using the complementary sex determination (csd) gene. Only individuals heterogeneous at the csd allele develop into females, and the homozygous develop into diploid males, which do not survive. The honeybees are therefore under selection pressure to generate new csd alleles. Previous studies have shown that the csd gene is under balancing selection. We hypothesize that due to the long separation from the mainland of Hainan Island, China, that the giant honey bees (Apis dorsata) should show a founder effect for the csd gene, with many different alleles clustered together, and these would be absent on the mainland.

Methodology/Principal Findings

We sampled A. dorsata workers from both Hainan and Guangxi Provinces and then cloned and sequenced region 3 of the csd gene and constructed phylogenetic trees. We failed to find any clustering of the csd alleles according to their geographical origin, i.e. the Hainan and Guangxi samples did not form separate clades. Further analysis by including previously published csd sequences also failed to show any clade-forming in both the Philippines and Malaysia.

Conclusions/Significance

Results from this study and those from previous studies did not support the expectations of a founder effect. We conclude that because of the extremely high mating frequency of A. dorsata queens, a founder effect does not apply in this species.     

Local honeybee (Apis mellifera mellifera L.) populations in the Urals

The COI-COII intergenic region of mitochondrial DNA (mtDNA) was studied in local honeybee (Apis mellifera mellifera) L. populations from the Middle and Southern Urals. Analysis of bee colonies in these regions revealed apiaries enriched in families descending from A. m. mellifera in the maternal lineage. These results confirm the suggestion of preservation of A. m. mellifera refuges in the Urals and provide grounds for work on the preservation of the gene pool of this bee variety, valuable for all Russia.     

中蜂抗菌物质的诱导

本文报道了用大肠杆菌注射处理中蜂Ａｐｉｓ ｃｅｒａｎａ Ｆａｂｒｉｃｉｕｓ后,用含菌培养基平板测活法,就中蜂抗菌物质的产生规律及抗菌活性进行了初步研究。结果表明,不同诱导源均可诱导中蜂产生抗菌物质,但诱导的抗菌物质的抗菌活性则有一定的差异。用大肠杆菌重复诱导则使中蜂的成活率和抗菌物质的抗菌活性有很大提高。注射大肠杆菌后冲蜂抗菌物持产生高峰在４８小时左右。诱导后产生的抗菌物质具有广谱性,对大肠杆菌Ａｓｃｈｅｒｉｃｈｉａ　ｃｏｌｉ、枯草芽孢杆菌 Ｂａｃｉｌｌｕｓ　 ｓｕｂｔｉｌｉｓ、苏云金杆菌 Ｂａｃｉｌｌｕｓ　ｔｈｕｒｉｎｇ－ｉｅｎｓｉｓ、巨大芽孢杆菌 Ｂａｃｉｌｌｕｓ　ｍｅｇａｔｈｅｒｉｕｍ、黑腐菌 Ｘａｎｔｈｏｍｏｎａｓ ｃａｍｐｅｓｔｒｉｓ　等均有抑菌作用,而对真菌白僵菌Ｂｅａｕｖｅｒｉａ　ｂａｓｓｉａｎａ未发现抑菌作用。中蜂麻醉方法以冷冻法最为简便、易行。     

The larva of Oecetis tripunctata (Fabricius, 1793) (Trichoptera,Leptoceridae)

Oecetistripunctata is a widely distributed leptocerid in Europe, ranging from the Iberian and Apennine peninsulas and the Central and Western European highlands to the plains of Eastern Europe. The long, single-bladed mandibles are indicative for a predacious lifestyle. This paper describes the previously unknown larva of Oecetistripunctata. Information on the morphology of the 5th larval instar is given, and the most important diagnostic features are illustrated. A synoptic key for the European species of Oecetis is also provided. In the context of existing identification keys the larva of Oecetistripunctata keys together with Oecetisintima and Oecetisnotata. Oecetistripunctata is separated from the other two species by the fact that a double row of long setal fringes is lacking at the hind tibiae and that several long setae are present on the protrochantinus.     

不同类型蜂箱对中华蜜蜂Apis cerana cerana Fabricius生产性能的影响

【目的】为了研究不同类型蜂箱对中华蜜蜂Apis cerana cerana Fabricius生产性能的影响。【方法】我们在综合考虑甘肃南部地区中华蜜蜂饲养模式、规模、当地环境等因素的基础上,选用标准蜂箱、原始蜂箱和生态蜂箱3种类型蜂箱在当地主要流蜜期进行蜂蜜生产试验。【结果】结果发现,蜂箱类型对蜂群的年产蜜量、存蜜量和取蜜次数存在显著影响(P<0.05),其中标准蜂箱在4个试验点的年产蜜量最高,原始蜂箱的存蜜量最高,而生态蜂箱在这2个指标上表现适中,标准蜂箱的年取蜜次数稍多。本研究中海拔和蜜源植物对蜂群生产性能没有明显影响。【结论】采用何种类型蜂箱进行中华蜜蜂养殖,应根据当地的环境状况、蜜源条件、文化及养蜂基础等多种因素综合考虑。     

Asymmetric introgression of African genes in honeybee populations (Apis mellifera L.) in Central Mexico

The Africanization of the honeybee (Apis mellifera) in South America is one of the most spectacular examples of biological invasions. In this study, we analyzed the Africanization process in Central Mexico along an altitudinal transect from 72 to 2800 m, using both mitochondrial and nuclear DNA markers. The mitochondrial analysis revealed that the two high-altitude populations had a significantly greater percentage of African mitotypes (95%) than the three lowland populations (67%), indicating successful spreading of Africanized swarms to these altitudes. All populations (highland and lowland) had a similar overall proportion of African alleles at nuclear loci (58%). Thus, all populations showed an asymmetric introgression of African nuclear and mtDNA. Colonies with African mitotypes had, on average, significantly more African nuclear alleles (60%) than those with European mitotypes (51%). Furthermore, the three lowland populations showed clear signs of linkage disequilibrium, while the two high-altitude populations did not, indicating recent genetic introgression events into the lowland populations.     

Hygropreference and brood care in the honeybee (Apis mellifera)

Terrestrial organisms need to limit evaporation from their bodies in order to maintain a homeostatic water balance. Owing to a large surface to volume ratio, arthropods are particularly susceptible to desiccation and have evolved behavioural and physiological mechanisms to conserve water. In social insects, water balance is also affected by the interactions between nestmates and by the architecture of the nest. For honeybees, humidity is particularly important for the brood because it affects the hatching success of eggs and because, unlike ants, honeybees cannot relocate their brood to parts of the nest with more favourable humidity. To advance the understanding of the water economy in honeybee nests, we investigated whether workers exhibit a hygropreference when exposed to a gradient of 24-90% relative humidity (RH) and whether the expression of this preference and their behaviour is affected by the presence of brood. The results show that young honeybee workers in the absence of brood exhibit a weak hygropreference for approximately 75% RH. When brood is present the expression of this preference is further weakened, suggesting that workers tend to the brood by distributing evenly in the gradient. In addition, fanning behaviour is shown to be triggered by an increase in humidity above the preferred level but not by a decrease. Our results suggest that humidity in honeybee colonies is actively controlled by workers.     

Anti-elastolytic activity of a honeybee (Apis cerana) chymotrypsin inhibitor

The honeybee is an important insect species in global ecology, agriculture, and alternative medicine. While chymotrypsin and trypsin inhibitors from bees show activity against cathepsin G and plasmin, respectively, no anti-elastolytic role for these inhibitors has been elucidated. In this study, we identified an Asiatic honeybee (Apis cerana) chymotrypsin inhibitor (AcCI), which was shown to also act as an elastase inhibitor. AcCI was found to consist of a 65-amino acid mature peptide that displays ten cysteine residues. When expressed in baculovirus-infected insect cells, recombinant AcCI demonstrated inhibitory activity against chymotrypsin (K_i 11.27 nM), but not trypsin, defining a role for AcCI as a honeybee-derived chymotrypsin inhibitor. Additionally, AcCI showed no detectable inhibitory effects on factor Xa, thrombin, plasmin, or tissue plasminogen activator; however, AcCI inhibited human neutrophil elastase (K_i 61.05 nM), indicating that it acts as an anti-elastolytic factor. These findings constitute molecular evidence that AcCI acts as a chymotrypsin/elastase inhibitor.     

Allozymic and morphometric analysis of populations in the Zygaena purpuralis complex (Lepidoptera, Zygaenidae)

In Central Europe and Asia Minor Zygaena purpuralis and Z. minos are two sibling species exhibiting a considerable geographic variation in several features. In this study we examine some populations from the Central and Southern Apennines (Italy) by comparing multivariate analyses of individual allozymic multilocus profiles and of individual morphometric profiles of male genitalia in order to assess their genetic and phenetic relationships.
Results indicate that populations of Z. purpuralis in the Apennines behave in rather different ways with respect to the occurrence of gene exchange with other gene pools. No gene flow appears to occur between two geographically close southern populations; however, extensive introgression, revealable at both the allozymic and morphometric level, seems to occur between some purpuralis and minos -like sympatric populations from Abruzzi. Evolutionary relationships among these peninsular Italy populations are discussed with reference to historical factors, that is, the occurrence of multiple Pleistocene refugia, which could have determined different degrees of isolation among gene pools. This situation is rather different from that previously outlined for Central Europe and present results suggest that the Z. purpuralis complex might include more than two biological species.     

Simultaneous and successive colour discrimination in the honeybee (Apis mellifera)

The colour discrimination of individual free-flying honeybees (Apis mellifera) was tested with simultaneous and successive viewing conditions for a variety of broadband reflectance stimuli. For simultaneous viewing bees used form vision to discriminate patterned target stimuli from homogeneous coloured distractor stimuli, and for successive discrimination bees were required to discriminate between homogeneously coloured stimuli. Bees were significantly better at a simultaneous discrimination task, and we suggest this is explained by the inefficiency with which the bees brain can code and retrieve colour information from memory when viewing stimuli successively. Using simultaneous viewing conditions bees discriminated between the test stimuli at a level equivalent to 1 just-noticeable-difference for human colour vision. Discrimination of colours by bees with simultaneous viewing conditions exceeded previous estimates of what is possible considering models of photoreceptor noise measured in bees, which suggests spatial and/or temporal summation of colour signals for fine discrimination tasks. The results show that when behavioural experiments are used to collect data about the mechanisms facilitating colour discrimination in animals, it is important to consider the effects of the stimulus viewing conditions on results.     

Early developmental processes in the fertilised honeybee (Apis mellifera) oocyte

The behaviour of sperm from egg penetration until creation of the zygote, the development of the maternal pronucleus, and the two first cleavage divisions were studied by use of fluorescence microscopy. It was found that 4-12 sperm penetrate the egg membranes prior to oviposition. Contrary to previous reports, we found that only 1-7 sperm move from their initial location just beneath the vitelline membrane and into the cytoplasm, where they develop into paternal pronuclei. At the time of oviposition, the oocyte nucleus was usually at the stage of metaphase I, rather than anaphase I as previously reported. At 26+/-2.5 minutes the meiotic process had entered the stage of metaphase II. The paternal and maternal pronuclei formed at 55+/-2.6 minutes, and they fused at 93+/-7.3 minutes. The mitotic division of the zygote was completed at 119+/-6.5 minutes.