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This paper reports the pollen sources selected by Apis mellifera in the area northwest of Santa Cruz (Argentina). It evaluates the relative biomass contribution and the protein content of the collected taxa. During the apicultural period (September 2008-March 2009) pollen loads from three colonies were collected every fortnight using pollen traps. Forty-two pollen types were found in the samples, from which 15 taxa had a biomass contribution over 1% of the total pollen crop. The main pollen sources were Brassicaceae, Taraxacum officinale, Convolvulus arvensis, Rosaceae, Salix spp. and Schinus marchandii (Anacardiaceae). Of the total pollen sources identified, 15 are new records for the bee pollen flora of Argentina and 13 are native plants of South America. The contribution of native flora occurred mainly in spring. Schinus marchandii, Mulguraea-Junellia type (Verbenaceae), Adesmia spp. (Fabaceae), Sysirinchium spp. (Iridaceae), Acaena spp. (Rosaceae), Astereae and Senecio spp. (Asteraceae) were the indigenous pollen types with the highest biomass contribution. Protein content of most collected pollen types was variable (between 13.25% and 24.43%). [ABSTRACT FROM AUTHOR]

Pollen morphology is widely used in taxonomic treatments of tribe Vernonieae, and differences in exine structure and aperture form have been described for many species within the genera comprising the tribe. However, in recent years a number of new species have been described and, in the present paper, we describe in detail the pollen of 24 species of the tribe which are either endemic or uncommon to certain regions of Argentina or of Paraguay. The pollen of these species are radially symmetrical and more or less spheroidal, 3-colporate or, in one species, 3-porate; the exine may be tectate or semitectate and microperforate, with echinate lophae or, in the 3-porate example, psilate lophae. Using a range of characteristics related to size, shape, wall thickness, apertures and tectum surface morphology, five of the six pollen types previously described for tribe Vernonieae, and a subtype, are recognized. Our results support the usefulness of pollen morphology in helping to determine the taxonomic position of species within tribe Vernonieae. [ABSTRACT FROM AUTHOR]

Here we present a revision of the elaterate pollen species that belong to the genus Galeacornea. We also describe a new species, Galeacornea guayaguensis sp. nov., from the Early Cretaceous (Albian?) of central-western Argentina. The specimens from this species were retrieved from sediments of the Lagarcito Formation (San Luis Basin) located at the Sierra de Guayaguás ranges in the San Juan province. Galeacornea guayaguensis shares with the other Galeacornea species the shape of the grain and the presence of an annular rim and distal appendages. The ridge-like appendages of G. guayaguensis are similar to those of G. stoveri and G. tarimensis, although they never fuse with the annular rim or with each other at their ends as it respectively occurs in these species. This new pollen species provides further evidence on the morphological variation of elaterate grains and extends the geographical distribution of Galeacornea to southern South America, far beyond the palaeophytogeographic Albian–Cenomanian Elaterates Province of the equatorial region. Finally, we propose a new combination of the species Quantonenpollenites crassatus to Galeacornea crassatus, considering that the morphological features of the former perfectly fit the diagnosis of the genus Galeacornea. [ABSTRACT FROM AUTHOR]

Plant resources foraged by Polybia scutellaris were identified by analysing the pollen content of 14 nests in Magdalena (Buenos Aires Province, Argentina). Six nests were inhabited at the time of collection. The palynological analysis indicated that the wasps visited 33 different taxa of flowering plants during the active cycle of the colonies. Flowers visited by the wasps belonged to both native and exotic plants located close to the nests. The variety of resources foraged by P. scutellaris characterises this species as a generalist flower visitor. [ABSTRACT FROM AUTHOR]

In the south of the Caldén district (Phytogeographical province of Espinal, Argentina) the availability of flowering along with the botanical origin and protein content of pollen harvested by honey bees, was studied. During two apiculture periods (from end August to early January) pollen loads were collected every fortnight using pollen traps. A total of 637.96 g of pollen loads was analysed. From 139 species recorded, only 29 were visited by honey bees. In terms of biomass the contribution of exotic plants was high at the end of the winter (Brassicaceae and Erodium cicutarium ); during this period of pollen shortage, honey bees collected spores of Puccinia interveniens . During the spring, the native plants ( Condalia microphylla , Chuquiraga erinacea , Discaria americana , Grindelia tehuelches , Larrea divaricata , Prosopis sp., Prosopidastrum globosum and Vicia pampicola ) were utilised. Those pollen types of high protein level were collected most intensively. [ABSTRACT FROM AUTHOR]

In order to determine the plants foraged by solitary Ptilothrix relata , the pollen content of food provisions was identified. The main pollen types confirm foraging by these bees on Malvaceae, Asteraceae and Onagraceae. Pollen sources belonging to Cucurbitaceae, Dipsacaceae and Portulacaceae families enrich the harvesting range of P. relata . According to the preliminary results, these bees can be considered more as narrowly polylectic than oligolectic because they collect pollen from a few unrelated species. Among the most abundant pollen collected, two major morphological types were recognized: (1) pollen with long spines (4-25 μm), many single apertures and large size (115-135 μm of diameter); and (2) tricolporate pollen with viscin threads. [ABSTRACT FROM AUTHOR]

Intradiurnal variation of arboreal pollen (AP) in Mar del Plata city is compared during three non - consecutive years of survey and described in relation to the associated weather. The daily pattern of pollen abundance has a maximum between 10:00 and 12:00 h, while a minimum occurs at 18:00 h. The first two years of survey showed homogeneous daily trends, but in 1995 the maximum and minimum concentrations were delayed because of the change in position of the collecting station. Arboreal pollen spectrum presented qualitative and quantitative changes in the three years analysed. Results indicate optimal conditions for diurnal dispersion of arboreal pollen are high temperatures and low relative humidity. Also interaction between source position and wind direction has important effects on the timing of the peaks of some pollen types. [ABSTRACT FROM AUTHOR]

We performed palynological analysis of 75 honey samples from the south of Caldén district, which is the part of the phytogeographical province del Espinal. Prosopis caldenia, "caldén" (Fabaceae) is the dominant arboreal species in this region. 79 pollen types that belong to 36 plant families were identified. Honeydew elements are absent or present in negligible amounts. Native flora is intensely utilized. Main nectar sources that characterize monofloral honey samples, are these natives Condalia microphylla (Rhamnaceae), Prosopis sp. and Vicia sp. (Fabaceae), Larrea divaricata (Zygophyllaceae) and Brassicaceae, which are foreign to the area. The pollen from these plants along with the pollen of Trichocline sp. (Asteraceae) and Prosopidastrum globosum (Fabaceae), Schinus fasciculatus (Anacardiaceae), Astereae and Lycium sp.(Solanaceae), characterize honey from Caldén. [ABSTRACT FROM AUTHOR]

Glochidiniumgen. nov., a ncw genus of Peridiniaceae based on Peridinium penardiforme Lindemann, is herewith erected. Its plate formula is: Po+X+4′+6′′+3C+4S+5′′′+2′′′′ Main diagnostic characters of this new genus are the presence of only 3 cingular plates (it lacks the transitionalone), the third cingular contacting the anterior sulcal plate, and an unusual sulcus holding a small triangular posterior sulcal plate. The thecal morphology and structure of two freshwater planktic species of the genus are described on the basis of LM and SEM observations. G. penardiforme comb. nov. is an infrequent species, albeit widely distributed world-wide. It has been recorded under the names of Peridinium, Glenodinium and Peridiniopsis. Peculiar features in the tabulation of the furrows and of the surface sculpture show that the species does not fit any of the known genera, for which reason the new genus Glochidinium is established. G. platygaster sp. nov., the second species included in the genus, differs from the former by its elongated body, the regular pentagonal shape of its large first apical plate, an equally large sulcal anterior plate, and well developed sculpture, chiefly on the antapical plates. Glochidinium penardiforme and G. platygaster were found in some reservoirs from central and northern Argentina. G. penardiforme was also found in several Argentine rivers and ponds. [ABSTRACT FROM PUBLISHER]

The morphology, energy reserves and viability of three species from Solanum Sect. Cyphomandropsis (Solanum adelphum Morton, S. glaucophyllum Desf. and S. stuckertii Bitter), which grow in Argentina were studied. The pollen grains are tricolporate and their characters are homogeneous. The only differences found among the species were the pollen grain size and the sculpture distribution. The surface features of exine were not readily visible under light microscope, but with SEM the sculpture appeared granulate. Analyses of the cytoplasm of pollen grains show the presence of oils. The average viability was high in two of the studied species (S. adelphum and S. glaucophyllum). An interesting difference was observed between the first and second day flowers of S. stuckertii. The second day flowers had high fertility but those from the first day had a very low fertility. In the latter case, an inner placentoid tissue of the anther hinders pollen release until the entire development is completed. The P/O ratio is linked to the breeding system. [ABSTRACT FROM AUTHOR]