Fani HATJINA
Hellenic Agricultural Organization - Demeter, Division of Apiculture, Department Member
Research Interests:
In this study, different context-dependent effects of imidacloprid exposure on the honey bee response were studied. Honey bees were exposed to different concentrations of imidaclo-prid during a time period of 40 days. Next to these... more
In this study, different context-dependent effects of imidacloprid exposure on the honey bee response were studied. Honey bees were exposed to different concentrations of imidaclo-prid during a time period of 40 days. Next to these variables, a laboratory-field comparison was conducted. The influence of the chronic exposure on gene expression levels was determined using an in-house developed microarray targeting different immunity-related and detoxification genes to determine stress-related gene expression changes. Increased levels of the detoxification genes encoding, CYP9Q3 and CYT P450, were detected in imidaclo-prid-exposed honey bees. The different context-dependent effects of imidacloprid exposure on honey bees were confirmed physiologically by decreased hypopharyngeal gland sizes. Honey bees exposed to imidacloprid in laboratory cages showed a general immunosuppres-sion and no detoxification mechanisms were triggered significantly, while honey bees in-field showed a resilient response with an immune stimulation at later time points. However, the treated colonies had a brood and population decline tendency after the first brood cycle in the field. In conclusion, this study highlighted the different context-dependent effects of imidacloprid exposure on the honey bee response. These findings warn for possible pitfalls concerning the generalization of results based on specific experiments with short exposure times. The increased levels of CYT P450 and CYP9Q3 combined with an immune response reaction can be used as markers for bees which are exposed to pesticides in the field.
Research Interests:
honey bees collected from 32 different localities in greece were studied based on the geometric morphometrics approach using the coordinates of 19 landmarks located at wing vein intersections. procrustes analysis, principal component... more
honey bees collected from 32 different localities in greece were studied based on the geometric morphometrics approach using the coordinates of 19 landmarks located at wing vein intersections. procrustes analysis, principal component analysis, and canonical variate analysis (cVa) detected population variability among the studied samples. according to the principal component analysis (pca) of pooled data from each locality, the most differentiated populations were the populations from the aegean island localities astypalaia, chios, and kythira. however, the populations with the most distant according to the canonical variate analysis performed on all measurements were the populations from heraklion and chania (both from crete island). these results can be used as a starting point for the use of geometric morphometrics in the discrimination of honey bee populations in greece and the establishment of conservation areas for local honey bee populations.
The genetic variability of honey bee populations, representing Apis mellifera macedonica, Apis mellifera cecropia and Apis mellifera carnica subspecies from the Balkan Peninsula countries of Bulgaria, Greece, Serbia and Montenegro, was... more
The genetic variability of honey bee populations, representing Apis mellifera macedonica, Apis mellifera cecropia and Apis mellifera carnica subspecies from the Balkan Peninsula countries of Bulgaria, Greece, Serbia and Montenegro, was studied using alloenzymic analysis of six enzyme systems (MDH-1, ME, EST-3, ALP, PGM and HK) corresponding to 6 loci. All loci were found to be polymorphic in most of the populations studied. The observed heterozygosity was found to range from 0.161 to 0.276. Allele frequencies of all loci were used to estimate Nei's (1972) genetic distance, which was found to range between 0.001 and 0.101 among the populations studied. UPGMA and neighbour-joining phylogenetic trees obtained by genetic distance matrix methods show that the honey bee populations from Bulgaria and Greece were clustered together, as were those from Serbia and Montenegro. La variabilidad genética de las abejas de la miel de la Península Balcánica meridional, basada en datos de alozimas Resumen La variabilidad genética de las poblaciones de abejas representas por las subespecies Apis mellifera macedonica, Apis mellifera cecropia y Apis mellifera carnica de los países balcánicos de Bulgaria, Grecia, Serbia y Montenegro, fue estudiada a partir de un análisis de alozimas de seis sistemas enzimáticos (MDH-1, ME, EST-3, ALP, PGM y HK) correspondientes a seis loci. Todos los loci resultaron ser polimórficos en la mayoría de las poblaciones estudiadas. La heterocigosidad observada varió en un rango de 0,161 a 0,276. Las frecuencias alélicas de todos los loci se utilizaron para estimar la distancia genética de Nei (1972), que varió en un rango entre 0,001 y 0,101 en las poblaciones estudiadas. Los árboles filogenéticos UPGMA y neighbour-joining obtenidos por métodos de matriz de distancia muestran que las poblaciones de abejas de miel procedentes de Bulgaria y Grecia se agrupan juntas, al igual que las de Serbia con Montenegro.
Honey bee samples from 54 apiaries originating from 37 geographic locations of Greece were screened for Nosema apis and Nosema ceranae. Furthermore 15 samples coming from 12 geographic locations were screened also for Paenibacillus larvae... more
Honey bee samples from 54 apiaries originating from 37 geographic locations of Greece were screened for
Nosema apis and Nosema ceranae. Furthermore 15 samples coming from 12 geographic locations were
screened also for Paenibacillus larvae and Melissococcus plutonius and seven honey bee virus species, for
the first time on a nation-wide level. There was a tendency in finding proportionally higher spore counts
in samples from apiaries that suffered important colony losses. P. larvae bacteria were identified in two
samples and each of the tested bee viruses could be detected in at least one of the examined samples,
with IAPV, CBPV and SBV being the least abundant and BQCV and DWV being the most abundant. In
the study we focused on polymorphism of a N. ceranae gene encoding a polar tube protein (PTP) as similar
genes were proven to be highly polymorphic in the microsporidian parasites Encephalitozoon cuniculi and
Encephalitozoon hellem. The polymorphism observed in the PTP gene sequences from a single sample (bee
hive) was unexpected and can thus be considered to be a major obstacle for genotyping.
Nosema apis and Nosema ceranae. Furthermore 15 samples coming from 12 geographic locations were
screened also for Paenibacillus larvae and Melissococcus plutonius and seven honey bee virus species, for
the first time on a nation-wide level. There was a tendency in finding proportionally higher spore counts
in samples from apiaries that suffered important colony losses. P. larvae bacteria were identified in two
samples and each of the tested bee viruses could be detected in at least one of the examined samples,
with IAPV, CBPV and SBV being the least abundant and BQCV and DWV being the most abundant. In
the study we focused on polymorphism of a N. ceranae gene encoding a polar tube protein (PTP) as similar
genes were proven to be highly polymorphic in the microsporidian parasites Encephalitozoon cuniculi and
Encephalitozoon hellem. The polymorphism observed in the PTP gene sequences from a single sample (bee
hive) was unexpected and can thus be considered to be a major obstacle for genotyping.
The genetic variability of 37 honey bee populations of Greece was studied, using geometric morphometrics analysis, on a sample of 798 honey bees collected from 105 different apiaries. The geometric morphometrics analysis was based on... more
The genetic variability of 37 honey bee populations of Greece was studied, using geometric morphometrics analysis, on a sample of 798 honey bees collected from 105 different apiaries. The geometric morphometrics analysis was based on coordinates of 19 landmarks located at vein intersections of the left wing. Statistical analysis of measurements, using MS Excel and Matlab packages, showed high hybridization between the Greek honey bee populations, probably due to beekeeping manipulations (migratory beekeeping and commercial breeding), represented with the standarized wings' shapes and revealed from the centroid size of the wings' shapes appearance. This estimation is confirmed in the UPGMC dendrogram, where all populations are mixed with the exception of Ikaria and Antikythira populations. Minor inter-population variability was detected only in Karpathos, Kos, Ikaria, Antikythira and Astypalaia islands populations. Samples from Crete island appear to be of a mixed origin, a result that it is in coincidence with a previous study based on mtDNA analysis (Harizanis and Bouga, 2003). Our results are in disagreement with Ruttner's (1988) morphometrics analysis and partly in disagreement with a preliminary study of ours (Hatjina et al., 2002), where we found that the populations from Rodos, Astypalaia and Ikaria were clearly differentiated from the rest ones and formed a distant group. Geometric morphometrics analysis can be very powerful in exploring intra-specific variation at the population level and it is largely employed in evolutionary studies concerning honey bees in Greece, combined with other approaches such as classical morphometrics and molecular markers. 598 Morphometric and MtDNA analysis… 599 INTRODUCTION The genetic variability of 37 honey bee populations from Greece was studied, using geometric morphometrics analysis. The geometric morphometrics analysis is a collection of approaches for the multivariate statistical analysis of Cartesian coordinate data, usually limited to landmark point locations (Bookstein, 1991), being, a powerful tool in evolutionary studies to explore intraspecific variation at the population level. According to Ruttner (1988) morphometrics analysis, four distinct honey bee races should exist in Greece: A.m.macedonica in Macedonia and Thrace regions, A.m.cecropia in Thessalia, Peloponnese and Kyklades islands, and A.m.adami in Crete. Bees of Ionian islands were assigned to A.m.carnica race. The aim of our study was to investigate the existence of variability in honey bee populations from Greece using geometric morphometrics analysis.
SUMMARY
ABSTRACT Most studies that have shown negative sublethal effects of the pesticide imidacloprid on honeybees concern behavioral effects; only a few concern physiological effects. Therefore, we investigated sublethal effects of imidacloprid... more
ABSTRACT Most studies that have shown negative sublethal effects of the pesticide imidacloprid on honeybees concern behavioral effects; only a few concern physiological effects. Therefore, we investigated sublethal effects of imidacloprid on the development of the hypopharyngeal glands (HPGs) and respiratory rhythm in honeybees fed under laboratory conditions. We introduced newly emerged honeybees into wooden mesh-sided cages and provided sugar solution and pollen pastry ad libitum. Imidacloprid was administered in the food: 2 μg/kg in the sugar solution and 3 μg/kg in the pollen pastry. The acini, the lobes of the HPGs of imidacloprid-treated honeybees, were 14.5 % smaller in diameter in 9-day-old honeybees and 16.3 % smaller in 14-day-old honeybees than in the same-aged untreated honeybees; the difference was significant for both age groups. Imidacloprid also significantly affected the bursting pattern of abdominal ventilation movements (AVM) by causing a 59.4 % increase in the inter-burst interval and a 56.99 % decrease in the mean duration of AVM bursts. At the same time, the quantity of food consumed (sugar solution and pollen pastry) per honeybee per day was the same for both treated and untreated honeybees.
Research Interests: Zoology and Apidologie
cecilia.costa@entecra.it The aim of this study was to investigate the effects of genotype-environment interactions on the survival, performance and disease susceptibility of honey bee colonies headed by queens originating from several... more
cecilia.costa@entecra.it The aim of this study was to investigate the effects of genotype-environment interactions on the survival, performance and disease susceptibility of honey bee colonies headed by queens originating from several areas in Europe. We included 16 different genotypes from different backgrounds (some from breeding programs with strong focus on specific traits, others from conservation programs with little selection) which were located in 21 locations in 11 countries across Europe. In each location the local strain was tested together with at least 2 other strains of different origin. The experiment ran from October 2009 until March 2012. No chemical treatments for Varroa were enacted. Of the observed colonies, 16% survived until the end of the experiment. A survival analysis showed highly significant effects of the test location, the genotype and the origin of queen (local vs. non-local) on the longevity of colonies. Colonies of local origin survived on average 80 ...
Research Interests: Apiculture and Beekeeping
ABSTRACT Most studies that have shown negative sublethal effects of the pesticide imidacloprid on honeybees concern behavioral effects; only a few concern physiological effects. Therefore, we investigated sublethal effects of imidacloprid... more
ABSTRACT Most studies that have shown negative sublethal effects of the pesticide imidacloprid on honeybees concern behavioral effects; only a few concern physiological effects. Therefore, we investigated sublethal effects of imidacloprid on the development of the hypopharyngeal glands (HPGs) and respiratory rhythm in honeybees fed under laboratory conditions. We introduced newly emerged honeybees into wooden mesh-sided cages and provided sugar solution and pollen pastry ad libitum. Imidacloprid was administered in the food: 2 μg/kg in the sugar solution and 3 μg/kg in the pollen pastry. The acini, the lobes of the HPGs of imidacloprid-treated honeybees, were 14.5 % smaller in diameter in 9-day-old honeybees and 16.3 % smaller in 14-day-old honeybees than in the same-aged untreated honeybees; the difference was significant for both age groups. Imidacloprid also significantly affected the bursting pattern of abdominal ventilation movements (AVM) by causing a 59.4 % increase in the inter-burst interval and a 56.99 % decrease in the mean duration of AVM bursts. At the same time, the quantity of food consumed (sugar solution and pollen pastry) per honeybee per day was the same for both treated and untreated honeybees.
Research Interests: Zoology and Apidologie
A Europe-wide experiment for assessing the impact of genotype-environment interactions on the vitality and performance of honey bee colonies: Experimental design and trait evaluation | Określenie wpływu interakcji genetyczno-środowiskowych na wydajność i witalność rodzin pszczelich w europie: Pro...more
Research Interests:
ABSTRACT Here we cover a wide range of methods currently in use and recommended in modern queen rearing, selection and breeding. The recommendations are meant to equally serve as standards for both scientific and practical beekeeping... more
ABSTRACT Here we cover a wide range of methods currently in use and recommended in modern queen rearing, selection and breeding. The recommendations are meant to equally serve as standards for both scientific and practical beekeeping purposes. The basic conditions and different management techniques for queen rearing are described, including recommendations for suitable technical equipment. As the success of breeding programmes strongly depends on the selective mating of queens, a subchapter is dedicated to the management and quality control of mating stations. Recommendations for the handling and quality control of queens complete the queen rearing section. The improvement of colony traits usually depends on a comparative testing of colonies. Standardized recommendations for the organization of performance tests and the measurement of the most common selection characters are presented. Statistical methods and data preconditions for the estimation of breeding values which integrate pedigree and performance data from as many colonies as possible are described as the most efficient selection method for large populations. Alternative breeding programmes for small populations or certain scientific questions are briefly mentioned, including also an overview of the young and fast developing field of molecular selection tools. Because the subject of queen rearing and selection is too large to be covered within this paper, plenty of references are given to facilitate comprehensive studies
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An understanding of the anatomy and functions of internal and external structures is fundamental to many studies on the honey bee Apis mellifera. Similarly, proficiency in dissection techniques is vital for many more complex procedures.... more
An understanding of the anatomy and functions of internal and external structures is fundamental to many studies on the honey bee Apis mellifera. Similarly, proficiency in dissection techniques is vital for many more complex procedures. In this paper, which is a prelude to the other papers of the COLOSS BEEBOOK, we outline basic honey bee anatomy and basic dissection techniques.El conocimiento de la anatomía y las funciones de las estructuras internas y externas es fundamental para muchos estudios sobre la abeja de la miel Apis mellifera. Del mismo modo, el dominio de técnicas de disección es vital para muchos procedimientos más complejos. En este trabajo, que es un preludio de los demás documentos del BEEBOOK COLOSS, describimos la anatomía básica de abejas y las técnicas básicas de disección.在西方蜜蜂的很多研究中都很有必要了解蜜蜂解剖学和内外结构的功能。同样地,熟练的解剖技术对于许多复杂的研究也很重要。作为COLOSS BEEBOOK的开篇,本文概述了基本的蜜蜂解剖学和基本的解剖技术。
Research Interests: Anatomy and Dissection
We aimed to determine the differences and similarities between Greek and Turkish propolis with respect to their chemical composition given that the two countries have many similarities in floral biodiversity. We observed that: a) Greek... more
We aimed to determine the differences and similarities between Greek and Turkish propolis with respect to their chemical composition given that the two countries have many similarities in floral biodiversity. We observed that: a) Greek propolis is different from the European-type propolis, having a high terpene content; therefore we can definitely characterize it as a Mediterranean type; b) the Turkish propolis collected along the coast line of the Aegean Sea is similiar to the examined Greek propolis; c) the remaining Turkish samples, originating from the European part of Turkey, were found to be similiar to the European-type propolis, having a high flavonoid content. Finally, especially two compounds, beta-elemene and totarol, were found in Greek samples in quite high amounts that are thought to have important biological properties.