Botanical and geographical origin of honey from the dry and humid Chaco ecoregions (Argentina)

To characterise the botanical and geographical origin of honey from the Chaco region (Argentina), 189 samples of honey were examined for pollen content using standard methodology. A general feature was the high representation of pollen from native arboreal plants, mainly of Fabaceae and the scarcity of pollen from herbaceous plants. One hundred and twenty-three samples proved to be unifloral. The most common were from: Prosopis alba, Helianthus annuus, Sarcomphalus mistol, Eugenia uniflora and Schinopsis balansae followed by those of Copernicia alba, Trithrinax schizophylla, Tessaria integrifolia, Baccharis-Eupatorium, Cynophalla retusa, Schinopsis lorentzii, Gleditsia amorphoides, Heimia salicifolia, Pisonia zapallo, Sagittaria montevidensis and Bulnesia sarmientoi. The pollen spectrum allowed the Dry and Humid Chaco ecoregions to be distinguished. The presence of pollen from cultivated crops and naturalised plants reflects a transitional complex between both ecoregions.     

Airborne Penicillium in the grain shops of Nagpur (India)

The airborne Penicillium spp. and total airborne fungal spore concentration was investigated in the grain shops of Nagpur city, India, using a volumetric Hi‐Air sampler system Mark II (Hi Media Laboratories Ltd., India). The mycotoxins were analysed from the Penicillium isolates obtained from the seeds by thin layer chromatography.

The mean concentration of the total fungi isolated from different grain shops ranged from 7.8×10² to 1.1×10³ CFU/m³. The mean concentration of Penicillium isolated from the air of grain shops ranged from 8.6×10¹ CFU/m³ (10.8%) to 1.7×10² CFU/m³ (19.9%). Among the 13 species of Penicillium which were isolated, P. citrinum Thom was the most prevalent species (24.2%), followed by P. oxalicum Currie & Thom (16.5), P. digitatum Saccardo (8.9%), P. janthinellum Biourge (8.7%), P. funiculosum Thom (8.3%), P. chrysogenum Thom (6.4%), P. purpurogenum Stoll (6.2%), P. brevicompactum Dierckx (4.8%), P. frequentans Westling (4.2%), P. italicum Wehmer (3.8%), P. rubrum Stoll (3.4%), P. expansum Link (2.9%) and P. cyclopium Westling (1.6%).

Penicillium species were also isolated from seeds such as wheat, maize, soybean, and groundnut. The mycotoxins roquefortin C, citrinin, rubratoxin B, cyclopiazonic acid, verrucosidin, mitorubrinic acid and two unknown metabolites were isolated from Penicillium isolates.     

Aeropalynologic analysis of La Plata City (Argentina) during a 3-year period

A continuous aeropalynologic survey of the atmosphere of La Plata was carried out between July 1998 and June 2001 in order to study flowering development from winter to summer using a Lanzoni volumetric spore trap. The total pollen spectrum was represented by 79 pollen types. Between 10 and 12 pollen types showed a relative concentration of more than 1% of the annual total. Airborne pollen was mainly represented by Platanus, Fraxinus, Cupressaceae, Poaceae, Urticaceae, Cyperaceae, Myrtaceae, Celtis, Casuarina and Morus during the 3-year period. Acer and Ambrosia pollen types were only dominant in the first 2 years. Maximum absolute concentrations were recorded in the the July 1998–June 1999 period, and the minimum concentrations were recorded in the July 2000–June 2001 period. The contribution of the arboreal pollen grains was higher than 68% relative to the annual total for each year. Two periods of maximum pollen emissions were found for each year: pollen from aboreal taxa predominated from July to October, and pollen from herbaceous taxa predominated from November to March. There was very little pollen in the atmosphere between April and June. The maximum arboreal and herbaceous pollen emissions were recorded during hours of daylight: at 10:00 and 14:00 hours.     

New species of Allorhogas Gahan (Hymenoptera: Braconidae) reared from galls on Lycium cestroides Schltdl. (Solanaceae) in Argentina

Allorhogas cordobensis sp. nov. (Hymenoptera: Braconidae: Doryctinae) is described from the province of Córdoba, Argentina. Its representatives can be distinguished from all other known species of the genus by the unusual morphology of the ovipositor tip and the expanded clypeus apically. Remarkably, this species is also characterized by having a tridentate mandible, a feature known only in exodont braconids, mostly of the subfamily Alysiinae. The new species was reared from stem galls on Lycium cestroides, which constitutes the second record of an Allorhogas species associated with galls on representatives of the plant family Solanaceae.     

Parachoerus carlesi (Mammalia,Tayassuidae) in the Late Pleistocene (northern Argentina,South America): paleoecological and palaeobiogeographic considerations

Abstract

The Tayassuidae is one of the first families of North American immigrant mammals that arrived into South America during the ‘Great American Biotic Interchange’. They have been found associated with Late Cenozoic deposits mainly in Argentina and Brazil, but also in Uruguay, Bolivia, Colombia, Peru and Venezuela. Theirs records within Argentina come from the Pampean Region, Mesopotamia and north-central region. Here, we report the first record of P. carlesi with precise stratigraphic (26.630 ± 370 14C years BP, Late Pleistocene) data in Argentina, precisely from the Chacoan region. This specimen represents the most complete fossil material of this extinct species, increasing its morphological and morphometrical knowledge, and it provides relevant ecological and climatic information. From a palaeoenvironmental point of view, the fauna registered in this paleontological site, includes taxa mainly adapted to open or semi-open and arid or semi-arid environments. The bearing sediments and the peculiarities of the faunal assemblages, as well as the chronological data, allow confirming that arid and semiarid conditions, with scarce or absent vegetation cover were developed in this area of Argentina during the last part of MIS 3 and beginning of MIS 2. These environmental conditions favored the settlement of megamammals adapted to open environments.     

Impact of the introduced honey bee (Apis mellifera) (Hymenoptera: Apidae) on native bees: A review

Abstract Interspecific competition for a limited resource can result in the reduction of survival, growth and/or reproduction in one of the species involved. The introduced honey bee (Apis mellifera Linnaeus) is an example of a species that can compete with native bees for floral resources. Often, research into honey bee/native bee competition has focused on floral resource overlap, visitation rates or resource harvesting, and any negative interaction has been interpreted as a negative impact. Although this research can be valuable in indicating the potential for competition between honey bees and native bees, to determine if the long‐term survival of a native bee species is threatened, fecundity, survival or population density needs to be assessed. The present review evaluates research that has investigated all these measurements of honey bee/native bee competition and finds that many studies have problems with sample size, confounding factors or data interpretation. Guidelines for future research include increasing replication and using long‐term studies to investigate the impact of both commercial and feral honey bees.     

Distribution of Castanea pollen in Galician honeys (NW Spain)

With the aim to know the importance of theCastanea pollen in the Galician honey(N. W. Spain), the interannual oscillations withinthe areas of production and the most activephenological period for bees, we have madethe melissopalynological analysis of: 599samples of honey collected during the period1990–1999 in Galicia, the production of 40beehives during three consecutive years(1990, 1991, 1992), the partial production during1990 of two beehives situated at distant pointsin our geography.     

Culicidae (Diptera) selection of humans,chickens and rabbits in three different environments in the province of Chaco, Argentina

Studies were conducted to determine the selection of humans, chickens and rabbits by Culicidae in three different environments in the province of Chaco, Argentina. Mosquitoes were collected fortnightly using cylindrical metal traps containing animal bait (chickens and rabbits). The mosquitoes were collected between June 2001-May 2002. During the same period and with the same frequency, mosquitoes biting the human operators of the traps were collected during the first 15 min of exposure within different time intervals: from 09:00 am-11:00 am, 01:00 pm-03:00 pm, 05:00 pm-07:00 pm and 09:00 pm-10:00 pm. A total of 19,430 mosquitoes of 49 species belonging to 10 genera were collected. Culex species mainly selected chicken bait and Wyeomyia species selected rabbit bait. Ochlerotatus and Psorophora species were more abundant in rabbit-baited traps. Anopheles triannulatus, Coquillettidia nigricans, Ochlerotatus scapularis, Mansonia titillans and Psorophora albigenu showed a strong attraction for human bait. The Anopheles, Coquillettidia, Culex and Mansonia species were more active between 05:00 pm-09:00 pm, while Ochlerotatus, Psorophora, Haemagogus and Wyeomyia were most active from 09:00 am-07:00 pm. This study provides additional information about the biology and ecology of arbovirus vectors in Chaco.     

Floral resources foraged by Geotrigona argentina (Apidae,Meliponini) in the Argentine Dry Chaco forest

This study is the first contribution to knowledge of the relationships between Geotrigona argentina and the plants of the Argentine Dry Chaco forest. A total of 1260 g of honey (corresponding to 146 pots) and 763 g of pollen (63 pots) stored in four underground nests was studied. The honey pots from each nest were homogenised and the four honey samples were analysed by melissopalynological methods, whereas the pollen pots were studied individually. Both classical counts and counts affected by the volume of the pollen types were carried out. Pollen data were statistically analysed. Additional data on both protein and lipid content is also provided. A total of 39 pollen taxa were identified. Pollen collection was focused on a few pollen taxa: Prosopis, Castela coccinea, Maytenus and Capparis; these taxa, together with Ziziphus mistol and Pisonia zapallo, were also important nectar sources. The preliminary results show that pollen collection varied seasonally, being most diverse in the summer when G. argentina incorporates herbaceous plants into its diet. The pollen collection spectrum of G. argentina is similar to that of other Trigonina bees in that the main plant species collected are a few large shrubs or trees, whose flowering consists of small and clustered flowers. Pots with large amounts of monofloral loads with pollen from only a few species suggests an organised foraging behaviour that includes the recruitment of foragers, such as that observed in other eusocial bees.     

Population structure and safety aspects of Enterococcus strains isolated from artisanal dry fermented sausages produced in Argentina

Enterococci population from Argentinean artisanal dry fermented sausage was identified and their safety aspects were evaluated. Species-specific PCR was used to distinguish between Enterococcus faecium (56%) and Enterococcus faecalis (17%). Other isolates (27%) were identified as Enterococcus durans , Enterococcus casseliflavus and Enterococcus mundtii by using 16S RNA gene sequence. RAPD analyses showed different biotypes for Ent. faecium and Ent. faecalis species. Low incidence of antibiotic resistance and high virulence traits in Ent. casseliflavus and Ent. faecalis were found; the majority of the Ent. faecium strains were shown to be free of virulence factors. The absence of virulence/resistance traits and the anti-Listeria activity of Ent. faecium isolates may be exploited to enhance natural preservation thereby guaranteeing organoleptic/safety characteristics of artisanal fermented sausages.     

Comparison of diurnal variation of airborne pollen in Mar del Plata (Argentina)

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.     

Thermoconformity strategy in the freshwater turtle Hydromedusa tectifera (Testudines,Chelidae) in its southern distribution area

Ectotherm species are not capable of generating metabolic heat; therefore, they present different strategies for regulating their body temperatures, ranging from a precise degree of thermoregulation to a passive thermoconformity with ambient temperatures. In reptiles, aerial basking is the most common mechanism for gaining heat. However, among aquatic reptiles, such as freshwater turtles, aquatic basking is also frequent. Hydromedusa tectifera is a turtle of exclusively aquatic and nocturnal habits widely distributed in South America. We studied the relationship between body temperature (Tb) of H. tectifera and its habitat, and explored the effects of sex, life stage and body size and mass on Tb. Fieldwork was conducted in two streams of a mountain area of central Argentina. We recorded cloacal temperature, size and mass of 84 turtles. We also determined individuals’ sex and life stage (adult/juvenile). Regarding ambient temperatures, we measured water temperature on the surface (Tsurf) and at depth of turtle capture (Tdepth) and air temperature. Mean Tb was 18.58 °C (Min = 10.20 °C; Max = 25.70 °C). Tsurf and Tdepth were highly correlated. Multi-model analysis using Akaike criterion indicated that Tb was strongly associated with water temperature, whereas air temperature and body size and mass did not show a significant effect. There was also no effect of turtle sex or life stage on Tb. Our results indicate that H. tectifera is a thermoconformer and eurythermal species. A nocturnal pattern of activity and a fully aquatic lifestyle are suggested as determinant factors.     

Descriptions of melissopalynological methods involving centrifugation should include data for calculating Relative Centrifugal Force (RCF) or should express data in units of RCF or gravities (g)

Techniques of pollen recovery involving centrifugation of honey pollen (melissopalynology) described in certain publications are difficult to 1) reproduce and 2) compare to other melissopalynological methods because dimensions of the centrifuge rotor were not described. Centrifugation data should be stated either in units of Relative Centrifugal Force (RCF) or gravities (g), or the data should be stated so RCF can be calculated using revolutions per minute (RPM) and the dimensions of the centrifuge rotor.     

Foraging behaviour of the stingless bee Melipona orbignyi (Hymenoptera: Apidae: Meliponini) in a dry forest assessed by multivariate analysis from palynological data

Pollen analysis was applied to study the botanical composition of honey and pollen stored by Melipona orbignyi in its southernmost distributional range. Many studies have revealed that robust buzzing bees of this genus are associated with diverse plant families, some of which are different to those exploited by the remaining genera of Meliponini. Cluster analysis was performed to assess similarity in botanical composition between pot-pollen and pot-honey provisions from different colonies. The results indicated that each colony was capable to access to different plant species for obtaining nectar and pollen, a fact observed when discarding the contaminated honey samples. As honey samples were not clustered together with other ones but with pollen samples indicating a similar botanical composition, it could be assumed that a same plant species provided nectar and pollen to bees. Resource partitioning was not clearly observed among a subset of late spring colonies, as two families of high richness of species and abundant in this dry forest (the mimosoid clade in Fabaceae and Capparaceae) were foraged. A higher number of synchronously sampled colonies would be necessary to detect this ecological aspect. The botanical composition of samples of M. orbignyi was governed by both random factors such as local and temporary flower availability plus preferences for particular plant species such as those from Solanaceae and Ximeniaceae. The Capparaceae and Ximeniaceae are here reported for the first time as intensively foraged pollen resources by the genus Melipona.     

Palynological characterisation of sedra honeys (Ziziphus lotus) produced in Algeria

Abstract

A melissopalynological study was carried out on 46 samples of Ziziphus lotus honey from Laghouat and Djelfa region (central Algeria). The number of pollen types identified per honey sample ranges between nine and 39 with a mean of 24. These correspond to 52 botanical families with 79 different pollen types in the whole samples. Asteraceae and Fabaceae families were present in all the samples where as Apiaceae, Brassicaceae and Nitrariaceae (Peganum harmala) were identified in more than 90%. Other plant families as Boraginaceae, Cistaceae, Myrtaceae, Oleaceae, Salicaceae or Urticaceae were identified in more than 50% of the samples but frequently as minor pollen. Ziziphus lotus pollen had a mean content of 68.9% (with a range of 45.3% to 93.4%). The secondary pollen types were Ononis natrix, Peganum harmala, Brassica napus, Echium and Olea europaea. Regarding the important pollen it is highlighted the presence Lotus t., Eucalyptus, Pimpinella anisum t., Trifolium t., Eryngium campestre t., Centaurea t., Galega officinalis t., Citrus or Scrophularia t. The sedra honeys of the studied region are characterised by their high content in pollen grains with a mean content of 188 403 grains/10 g. The presence of some pollen types in the pollen spectra of honeys such as Peganum harmala, Thapsia garganica, Launaea, Muscari comosum, Carthamus or Limonium bonduellei together several Asteraceae as Centaurea, Taraxacum, Carduus, Artemisia and Matricaria was proposed as geographical markers of this honey type.     

The role of Mimosa L. (Fabaceae) on pollen provision of Melipona asilvai Moure 1971 in a Caatinga area from Brazil

The pollen spectrum of Melipona asilvai pollen samples, collected over the course of two years, was analysed with the objective of inferring the flora visited by this bee in a region of Caatinga in Bahia, Brazil. This study also evaluated the role of Mimosa species as a source of resources used by Melipona asilvai. Forty-eight pollen types, distributed in 22 families, were morphologically distinguished. The family Fabaceae was notable in the pollen spectrum, with 14 identified types. Mimosa was the most representative and found in all samples analysed, sometimes with high frequency. Mimosa tenuiflora had a 91.5% frequency of occurrence in the sample set and greatly contributed to the monthly samples with percentages over 95% in four of the months analysed. The other Mimosa pollen types identified were M. arenosa, M. quadrivalvis, M. misera and M. pudica. In addition, the Angelonia (Plantaginaceae) type in three samples and the Chamaecrista racemosa (Fabaceae) type in one sample had frequencies over 50% in the pollen spectrum. Other very frequent types in the sample set, occurring in more than 50% of the samples analysed, were the following: Melastomataceae, Solanum paniculatum (Solanaceae), Borreria verticillata (Rubiaceae) and Myrcia (Myrtaceae). Despite the variety of floral sources recorded, it was possible to identify the floral preference of this bee as Mimosa, indicating the importance of Mimosa species as a source of resources used by this bee.     

A histological study of microsporogenesis in Tarenna gracilipes (Rubiaceae)

We studied the microsporogenesis in Tarenna gracilipes (Hayata) Ohwi, with special attention to the mode of exine deposition and tapetum development. We based this research on light (LM), scanning electron (SEM) and transmission electron microscopic (TEM) observations of developing anthers of T. gracilipes, from the microspore mother cell stage towards anther dehiscence. Evidence is supplied that the microsporogenesis in T. gracilipes can be considered as simultaneous. Columellae, foot layer and tectum develop in a fibrillar matrix. Similar with earlier studies in Rubiaceae species, a single white line formed near the plasmalemma in the extra‐apertural region. The developing endexine dilated into several white line centered lamellae at the apertures. An annulus is formed around the inner surface of each pore. In the mature intine two strata can be distinguished. At the apertures thick onci are formed protruding through the apertures thereby forming papillae, a common feature in Rubiaceae. In Rubiaceae species amoeboid as well as secretory tapeta are reported. In T. gracilipes it is shown that the tapetum cells possess in all developmental stages characteristics of the secretory type. During microsporogenesis the tapetum cytoplasm undergoes considerable changes which may indicate cycles of hyperactivity. Sporopollenin deposition on the pre‐orbicules is mediated by white lines showing correlations with endexine, annulus and columellae ontogeny. These findings corroborate the idea that orbicule wall development can represent a model to study sporopollenin deposition. At anther dehiscence Ca‐oxalate crystals are released out of the ruptured septum cells into the locule, providing a possible visual signal for pollinators.     

四川被子植物区系特征的初步研究

四川地区被子植物区系188科1493属8711种及1252变种,全球50％以上的科都有代表,与毗邻地区及世界植物区系有着广泛而密切的联系。区系古老而原始,珍稀孑遗类群丰富;单型或少种的科属众多,含100种以上的大科和大属也十分繁荣;含5种以下的属占76.89%,但占总属数约22.64%的多种属和大属是区系的主体,包含区系总种数的63.28%。科的分布类型有明显热带性质,属、种的分布类型反映出典型的亚热带属性。优势现象明显,特有类群和表征类群丰富。该地区被子植物区系对中国乃至东亚都有代表性。     

贝加尔湖-钻孔(BDP 96-1)的孢粉分析

贝加尔钻探计划（BDP）中的96－1井位于贝加尔湖中央的科学湖脊,1996年冬从位于332m水深以下的钻井采样,钻孔从湖底向下深2000m,根据古地磁资料,钻孔年代推测为5．1Ma,Tsuga,Lepidobalanus,Ulmaceae,Tilia和Corylus发现于钻孔的下部约60m,因为这些化石花粉目前在贝加尔湖地区已经消失,说明该钻孔上部的气候比下部的冷,因此,第四纪的气候比晚第三纪的更为干冷。在亚北极的西伯利亚,冰期时期以草本植物花粉占统治地位,花粉浓度较低,而在间冰期时期以木本花粉为主,花粉浓度较高,在间冰期时期硅藻及有机物总量增加,潮湿度（wet density)及氧同位素比率都降低,相反,在冰期时期硅藻含量及有机物总量降低,而潮湿度（wet dendity)和氧同位素比率都增加。