La subfamilia Bombinae (Him., Apidae) de la fauna española

Tesis Univ. Complutense de Madrid, 1984.Depto. de Genética, Fisiología y MicrobiologíaFac. de Ciencias BiológicasTRUEProQuestpu

Eumelanin and pheomelanin are predominant pigments in bumblebee (Apidae: Bombus) pubescence

Background: Bumblebees (Hymenoptera: Apidae: Bombus) are well known for their important inter- and intra-specific variation in hair (or pubescence) color patterns, but the chemical nature of the pigments associated with these patterns is not fully understood. For example, though melanization is believed to provide darker colors, it still unknown which types of melanin are responsible for each color, and no conclusive data are available for the lighter colors, including white. Methods: By using dispersive Raman spectroscopy analysis on 12 species/subspecies of bumblebees from seven subgenera, we tested the hypothesis that eumelanin and pheomelanin, the two main melanin types occurring in animals, are largely responsible for bumblebee pubescence coloration. Results: Eumelanin and pheomelanin occur in bumblebee pubescence. Black pigmentation is due to prevalent eumelanin, with visible signals of additional pheomelanin, while the yellow, orange, red and brown hairs clearly include pheomelanin. On the other hand, white hairs reward very weak Raman signals, suggesting that they are depigmented. Additional non-melanic pigments in yellow hair cannot be excluded but need other techniques to be detected. Raman spectra were more similar across similarly colored hairs, with no apparent effect of phylogeny and both melanin types appeared to be already used at the beginning of bumblebee radiation. Discussion: We suggest that the two main melanin forms, at variable amounts and/or vibrational states, are sufficient in giving almost the whole color range of bumblebee pubescence, allowing these insects to use a single precursor instead of synthesizing a variety of chemically different pigments. This would agree with commonly seen color interchanges between body segments across Bombus species

Searching for Molecular Markers to Differentiate Bombus terrestris (Linnaeus) Subspecies in the Iberian Peninsula

Bumblebees (genus Bombus Latreille) are pollinator insects of great ecological and economic importance, which commercial use for pollination has increased since the 80s. However, the introduction of foreign Bombus terrestris (Linnaeus) has resulted in a decline of native bumblebee populations in Japan, Chile or Argentina among others. To study the potential introgression of commercial B. terrestris into the Iberian endemic subspecies Bombus terrestris lusitanicus Krüger, it is necessary to find a precise molecular marker that differentiates both subspecies. For this purpose, comparative analyses were carried out between B. t. lusitanicus and B. t. terrestris (Linnaeus) from Spain and from Belgium by sequencing the nuclear genes elongation factor 1-α and arginine kinase and the mitochondrial gene 16S ribosomal RNA, and genotyping with eleven microsatellite loci. No differentiation was observed at the nuclear level, but haplotypes found within the 16S sequence correlated with the morphological characterization of the subspecies. In a case study including individuals sampled before the establishment of bumblebee rearing companies and others from recent samplings, we detected hybrid individuals (those with non-matching morphological subspecies and 16S haplotype) more frequently in the south supporting the naturalization of commercial B. t. terrestris and introgression events between both subspecies. This marker should be used in Iberian populations with the aim to support management and conservation actions in endemic populations of B. t. lusitanicus

NUEVOS CASOS TERATOLÓGICOS EN APOIDEA (HYMENOPTERA)

This work deals with three teratological specimens of Apoidea that belong to the families Halictidae, Anthophoridae and Apidae and the genera Lasioglossum Curtis, 1833, Nomada Scopoli, 1770 and Bombus Latreille, 1802. According to BALAZUC (1948, 1958) these cases are local and preimaginal abnormalities produced in gaster segmentation, in two of the specimens, and in the third the malformations appear in head and the mesothoracic legs. Every possible ethiology is studied too.Se estudian varias conformaciones teratológicas que afectan a tres individuos de la superfamilia Apoidea, pertenecientes a las familias Halictidae, Anthophoridae y Apidae y que corresponden a los géneros Lasioglossum Curtis, 1833, Nomada Scopoli, 1770 y Bombus Latreille, 1802. De acuerdo con BALAZUC (1948, 1958), tales alteraciones se clasifican dentro de las anomalías locales preimaginales: en dos de los ejemplares se trata de errores en la segmentación del gáster y en el tercer ejemplar las malformaciones afectan a la cabeza y patas mesotorácicas. Se indica, asimismo, la posible etiología de estas particularidades morfológicas

Preliminary report on cross-species microsatellite amplification for bumblebee biodiversity and conservation studies

The Iberian Peninsula holds a high diversity of bumblebees but there is a general lack of information about their biodiversity in this area. To overcome this and facilitate conservation studies, we present two novel multiplex assays for the amplification of six and five microsatellite loci respectively. Both assays successfully amplified for most of the studied species in the Iberian populations. Sibling workers and population genetic parameters were analysed in the managed species B. terrestris and in the wild species B. monticola and B. mesomelas, demonstrating the capability of these multiplex assays for biodiversity studies of both managed and wild bumblebee species

First data on the prevalence and distribution of pathogens in bumblebees (Bombus terrestris and Bombus pascuorum) from Spain

Bumblebees provide pollination services not only to wildflowers but also to economically important crops. In the context of the global decline of pollinators, there is an increasing interest in determining the pathogen diversity of bumblebee species. In this work, wild bumblebees of the species Bombus terrestris and Bombus pascuorum from northern and southern Spain were molecularly screened to detect and estimate prevalence of pathogens. One third of bumblebees were infected: while viruses only infected B. pascuorum, B. terrestris was infected by Apicystis bombi, Crithidia bombi and Nosema bombi. Ecological differences between host species might affect the success of the pathogens biological cycle and consequently infection prevalence. Furthermore, sex of the bumblebees (workers or males), sampling area (north or south) and altitude were important predictors of pathogen prevalence. Understanding how these factors affect pathogens distribution is essential for future conservation of bumblebee wild populations

Spatial and temporal patterns of genetic diversity in Bombus terrestris populations of the Iberian Peninsula and their conservation implications

The bumblebee Bombus terrestris is used worldwide for crop pollination. Despite its positive impact on crop yield, it has become a widespread threat to biodiversity due to its interactions with local bumblebee populations. Commercial subspecies introduced to the Iberian Peninsula since the 1990s without any regulation have colonized the environment, with evidence of naturalization and introgression with the endemic subspecies Bombus terrestris lusitanicus. We have used mitochondrial and nuclear genetic data to describe the current genetic diversity of the Iberian population and to estimate the expansion of commercial bumblebees. Samples from the natural distribution range of the commercial subspecies, the natural intergradation area between the two subspecies and from a period prior to the use of commercial colonies (i.e., before the 1990s) have been used for comparison. Our results show that the mitochondrial haplotype of the commercial breeds has spread throughout the territory, which, together with subtle changes observed in the nuclear genetic diversity of the populations, indicates that hybridization and consequent introgression are occurring in most of the peninsula. It is, therefore, necessary to improve the existing legislation concerning the management and exportation of commercial bumblebees to conserve locally adapted populations

Bee trypanosomatids: first steps in the analysis of the fenetic variation and population structure of Lotmaria passim, Crithidia bombi and Crithidia mellificae

Trypanosomatids are among the most prevalent parasites in bees but, despite the fact that their impact on the colonies can be quite important and that their infectivity may potentially depend on their genotypes, little is known about the population diversity of these pathogens. Here we cloned and sequenced three non-repetitive single copy loci (DNA topoisomerase II, glyceraldehyde-3-phosphate dehydrogenase and RNA polymerase II large subunit, RPB1) to produce new genetic data from Crithidia bombi, C. mellificae and Lotmaria passim isolated from honeybees and bumblebees. These were analysed by applying population genetic tools in order to quantify and compare their variability within and between species, and to obtain information on their demography and population structure. The general pattern for the three species was that they were subject to the action of purifying selection on nonsynonymous variants, the levels of within species diversity were similar irrespective of the host, there was evidence of recombination among haplotypes and they showed no haplotype structuring according to the host. C. bombi exhibited the lowest levels of synonymous variation (πS= 0.06 ± 0.04%) — and a mutation frequency distribution compatible with a population expansion after a bottleneck — that contrasted with the extensive polymorphism displayed by C. mellificae (πS= 2.24 ± 1.00 %), which likely has a more ancient origin. L. passim showed intermediate values (πS= 0.40 ± 0.28 %) and an excess of variants a low frequencies probably linked to the spread of this species to new geographical areasThis study was supported by the Ministerio de Economía y Competitividad (MINECO) (grant number CGL2012-34897), the Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA) - European Regional Development Fund (ERDF) (grant numbers E-RTA2014-00003-C03-01, 02 and 03), the Eva Crane Trust (grant number ECTA_20210308) and the Fundación Séneca - Agencia de Ciencia y Tecnología de la Región de Murcia (grant of Regional Excellence19908/GERM/2015)S