Sequence analysis of bacterial DNA in the colon and stomach of the Tyrolean Iceman

The male human body found in an Alpine glacier on September 19, 1991 ("Tyrolean Iceman") has, for the first time in history, given scientists a chance to perform detailed anatomical, histological, and molecular investigations on the organs of a person from the Neolithic Age (5350-5100 B.P.). In the present study, tissue samples aseptically taken from the stomach and the colon of the mummy were utilized for DNA extraction, and the DNA was PCR-amplified, using primer pairs designed to bind to fragments of the 16s ribosomal RNA gene (16s rDNA) of a broad range of bacteria. The PCR products were cloned in plasmid vectors, and the recombinant clones (amplicons) were sequenced. The sequence data were finally used for scanning data libraries containing the corresponding sequences of present-day bacteria, to infer the putative ecophysiology of the ancient ones. The same procedure was repeated on some fragments of grass from the clothing found near the corpse. These fragments were taken as a control of the microbiological situation of the glacier. The results show that the flora of the Iceman's stomach is entirely composed of Burkholderia pickettii, an organism commonly found in aquatic habitats. The colon, on the other hand, contains several members of the fecal flora of humans, such as Clostridium perfringens, C. ghonii, C. sordellii, Eubacterium tenue, and Bacteroides sp. The Iceman's colon, however, was found to contain, rather unexpectedly, also some members of the genus Vibrio. The results are discussed in light of what is known about the preservation of microbial DNA at the Iceman's site and of previous parasitological studies performed on the Iceman himself and on human coprolites.     

Riccia rhenana Lorb. ex. K.Mill. in Britain

Abstract

A single, small moss leaf has been found among very small amounts of contents extracted from the Tyrolean Iceman's colon. It belongs to the species Neckera complanata Hedw., a woodland moss of low to moderate altitudes. The leaf was accidently ingested and not consumed as food.     

Seasonal variation in the diet of Tetrix tenuicornis (Orthoptera: Tetrigidae)

Many animals change their diet during the season according to food availability. The current field study determined whether the groundhopper Tetrix tenuicornis (Orthoptera: Tetrigidae), which specializes on moss and detritus, changes its diet during the season under conditions in which food components are constantly available. Dietary differences of T. tenuicornis were studied through the season, from May to October, by alimentary tract analyses. Detritus and moss (phylloids) dominated the alimentary tract contents, and other components were found in only minor amounts. The diversity of moss species in the alimentary tract varied during the season, and more moss species were consumed in spring and summer than in autumn. Diet was affected by developmental stage, sex (females consumed more food than males), population and abiotic factors. The rate at which detritus was consumed was significantly affected by the ambient temperature but the rate at which moss was consumed was mainly affected by relative humidity. Later instars consumed greater amounts of detritus than younger instars, and this difference corresponded to body size.     

14. Lake Sedmo Rilsko (Bulgaria): Lateglacial vegetation history

The length of the pollen deposition period covered by an individual moss sample is a matter of discussion. Here we evaluate (1) how many years of pollen deposition are contained in individual moss samples, (2) which factors (i.e. moss type, geographical location and thickness of sample) affect the pollen content, and (3) whether the time span of the pollen deposited in the moss is related to the pollen type. The pollen deposition period covered by 20 individual moss samples adjacent to pollen traps was estimated using the accumulation method. The investigated moss samples usually contain pollen from a period of two to five years. The length of the time period covered by the moss depends on the thickness of the moss cushion and, therefore, we recommend estimating the time period over which the moss has been growing by the increment method. Compared to pollen traps, mosses tend to accumulate more Poaceae and bisaccate grains (especially Picea) but less Cyperaceae pollen. Betula and pollen tetrads tend to be equally represented in mosses and traps. This study demonstrates that moss samples may contain sufficient pollen to be a reliable modern analogue for Quaternary peat and sediment samples but cannot be used to calculate pollen accumulation rates.     

Comparisons of moss polster and pollen trap data: a pilot study

Modern pollen-vegetation relationships have been explored in recent years through analysis of either pollen trap (= absolute results) or moss polster contents (= relative results). In the past few attempts were made to compare data from these two sources. It was the aim of the present study to achieve this comparison through more exact sampling of moss polsters. A pilot study was carried at Morton Lochs, Fife, Scotland where pollen traps have been sampled continuously for ten years. Moss samples were collected from cushions adjacent to two of the pollen traps during May 1985, 1986 and 1987. Moss polsters were sampled usingan equivalent surface cross-section area to that of the traps. In comparing the pollen results from the two sources some similarities can be identified, but in general there are more inconsistencies. These may be traced to difficulties in the precision of moss sampling, variable rates of moss growth and local deposition factors. It is considered that further study, in which these difficulties are minimised, would be justified. Ultimately it is hoped that precise sampling of mosses will produce sufficiently reliable modern pollen rain results to enable pollen-vegetation studies to move away from relative (percentage) values without requiring long-term artificial pollen trapping techniques.     

Fine characterization of the Iceman's mtDNA haplogroup

Starting from specimens of the intestinal contents of the so-called Tyrolean Iceman or Otzi (5,350-5,100 years before present), it was possible by polymerase chain reaction to amplify fragments of the human mitochondrial DNA (mtDNA) control region that correspond to the sequence found in 1994 at the Munich and Oxford laboratories and which had been attributed to the original DNA of the mummy. The particularly favorable condition of the specimens, showing very low contamination levels, made it easier to extend the analyses to the coding region, which had not previously been considered. The mtDNA of the European population is currently divided into nine (H, T, U, V, W, X, I, J, and K) main groups (haplogroups). The K haplogroup, in particular, is composed of two (K1 and K2) subclusters. The results demonstrate that the Iceman's mtDNA belongs to the K1 subcluster, yet it does not fit any of the three known branches (a, b, and c) into which the K1 subcluster is presently divided. In addition, some other sites, reported to be linked to environmental adaptation or pathologies, were investigated.     

Cupressaceae pollen: new data about diffusion,record and preservation

Abstract

Cupressaceae is one of the most widespread families in the Mediterranean region, widely used as ornamental trees both in cities and extra urban areas. The family is also known to produce a considerable amount of pollen grains. Nevertheless, Cupressaceae pollen is generally scarce in sediments and it is attested to be one of the most underrepresented pollen in ancient spectra. Cupressaceae pollen diffusion was detected by means of two sampling methods: moss cushions, which are able to accumulate pollen grains for several successive years, and volumetric sampler, which records the airborne pollen day by day. The study was conducted in the city of Florence (Italy), repeating moss samplings at the same sites for three times. The comparison between the two sampling methods revealed the low preservation of this pollen type and suggested that even low quantities of this pollen may indicate the local presence of the source plants. In order to test the contribution of the local pollen sources to the background of the airborne pollen, the pollen content of moss cushions was also related to the number of Cupressaceae plants surroundings each sampling site. The results indicate a noticeable influence of the plants growing in a short-range distance.     

Comparing pollen spectra from modified Tauber traps and moss samples: examples from a selection of woodlands across Europe

This paper compares pollen spectra derived from modified Tauber traps and moss samples from a selection of woodland types from Bulgaria, the Czech Republic, Georgia, Greece, Poland, Switzerland and Wales. The study examines the representation of individual taxa in the two sampling media and aims to ascertain the duration of pollen deposition captured by a moss. The latter aim was pursued through the calculation of dissimilarity indexes to assess how many years of pollen deposited in a pollen trap yield percentage values that are most similar to those obtained from the moss. The results are broadly scattered; the majority of moss samples being most similar to several years of pollen deposition in the adjacent trap. For a selection of samples, a comparison of the pollen accumulation rate in pollen traps with the pollen concentration in the moss per unit surface indicates that the entrapment and/or preservation of individual pollen types in the moss differ from that in the pollen trap. A comparison of the proportion of different taxa in the moss with the pollen spectrum of 2 years of pollen deposition in the trap also revealed large differences. There is a tendency for bisaccate grains such as Pinus and Picea to have a higher representation in moss than in traps but there is considerable regional variation. The results indicate that pollen proportions from moss samples often represent the pollen deposition of one area over several years. However, bisaccate pollen grains tend to be over-represented in moss samples compared to both pollen traps and, potentially, lake sediments.     

Evaluation of the nutritive value of maize for honey bees

In modern managed agro-ecosystems, the supply of adequate food from blooming crops is limited to brief periods. During periods of pollen deficiencies, bees are forced to forage on alternative crops, such as maize. However, pollen of maize is believed to be a minor food source for bees as it is thought to be lacking in proteins and essential amino acids. This study was conducted to verify this assumption. In maize, a strikingly low concentration of histidine was found, but the amount of all other essential amino acids was greater than that of mixed pollen. The performance and the immunocompetence of bees consuming a pure maize pollen diet (A) was compared to bees feeding on a polyfloral pollen diet (B) and to bees feeding on an artificial substitute of pollen (C). Consumption of diets A and C were linked to a reduction in brood rearing and lifespan. However, no immunological effects were observed based on two parameters of the humoral immunity.     

A comparison between modern pollen spectra of moss cushions and Cundill pollen traps

Pollen spectra of 23 Cundill pollen traps from 23 different sampling sites in Southwest Turkey are compared with the corresponding pollen spectra of moss cushions from the same sites. The Cundill pollen traps represent the modern pollen rain data from one year whereas the moss cushions represent the pollen rain of several years. The comparative study reveals some main differences between the two pollen entrapment media. The one-year entrapment medium (pollen trap) appears to be more sensitive for local (releve area 10x10 m) and regional (100-500 m, or a few kilometres for Olea europaea) vegetation. Pollen spectra of moss cushions are dominated by high pine pollen percentage values and hardly sense fine vegetation structures. The conclusion of this comparative modern pollen study allows to interpret fossil sediment spectra from the Near East in a more critical way. It is concluded that one should preferably sample rapidly deposited sediments for palynological analyses, as the resulting highresolution pollen diagrams will be most informative about the former vegetation patterns.     

Entrapment of long-distance transported pollen grains by various moss species in coastal Victoria Land,Antarctica

Summary In northern Victoria Land (continental Antarctica, between 72° and 76°S, 162° and 169°E), 18 moss samples have been collected and analysed for the presence of pollen. In turfs and cushions of 8 different moss species, at least 27 pollen taxa could be identified. The pinus-type pollen and those of grasses were very common. More than 60% of the total grains were damaged or could not be identified. There is evidence that the Antarctic continent could act as a sink for wind-transported pollen from sub-Antarctic islands or from plants (native or cultivated) in South America, Australia, New Zealand and South Africa. However, the pollen concentration in air ( 1 pollen grain/100 m³) and its entrapment rate on moss (about 0.12 grain/cm²/year) result in a very low pollen density in these plants.     

Assimilation of carbon and nitrogen from pollen and nectar by a predaceous larva and its effects on growth and development

Abstract. 1. Predaceous insects may benefit from feeding on non‐prey foods, such as pollen, nectar, and honeydew, because they can provide nutrients that help maintain metabolism and enhance overall nutrient intake. Yet, the extent to which predaceous insects can assimilate non‐prey food and the importance of diet mixing during particular life history stages is poorly understood. In this study the relative contribution of an omnivorous diet to the growth and survivorship of a predaceous larva was tested in a hypothetical situation in which nutritionally optimal prey was not available. The study system comprised a predaceous larva (second‐ and third‐instar larvae of the green lacewing Chrysoperla carnea), nutritionally poor prey (larvae of Drosophila melanogaster), and non‐prey food (pollen suspension, a mixture of bee pollen and artificial nectar (1 M sucrose solution)). Chrysoperla carnea larvae in the mixed diet treatment were provided with both Drosophila larvae and pollen suspension, while those reared on the prey and non‐prey diet treatments received only Drosophila larvae or pollen suspension respectively. 2. The inclusion of pollen and sucrose in their diet enhanced the growth of C. carnea larvae. Second instars reared on the mixed diet developed significantly faster than their cohorts reared on the prey diet, however third instars reared on the mixed diet did not develop faster than their cohorts reared on the prey diet. Larvae reared on the mixed diet became larger adults than did those reared on either the prey or non‐prey diets. Third instars reared on the non‐prey diet completed their development while second instars in the non‐prey diet treatment failed to pupate. 3. Stable isotope analysis indicated that the larvae obtained most of their carbon (55–73%) and nitrogen (71–73%) from Drosophila but acquired only a minor amount of carbon (2–5%) and nitrogen (3–11%) from pollen. Larvae reared on the mixed and non‐prey diets acquired a relatively significant amount of carbon (23–51%) from sucrose. 4. A model, which included a novel fractionation factor to account for the isotopic effect of metamorphosis, was developed to explain the proportion of larval growth attributable to each diet item. It explained the adult δ¹³C values to within 0.2‰ and adult δ¹⁵N values to within 0.7‰ in all treatments. 5. Adults fed ¹⁵N‐labelled pollen as larvae retained the ¹⁵N signal of the pollen as adults. 6. The collective results of this study support the view that, despite their dependence on prey arthropods to obtain most of their dietary nitrogen, omnivorous lacewing larvae can enhance their growth and development by supplementing their diets with alternative non‐prey food resources. This finding is consistent with the notion that omnivory has evolved as a feeding strategy to acquire both additional nitrogen as well as trace nutrients.     

Effect of Diet History on Prey and Pollen Food Choice by Two Lady Beetle Species

Mixed diets of prey and plant-provided foods, such as pollen, have been shown to benefit a wide range of arthropods. However, diet shifting between these two very different food sources remains poorly understood. We hypothesized that previous diet should influence subsequent time allocation between prey and plant food types; to reach a balanced diet, consumers are expected to allocate more time to resources previously lacking in their diet. We tested this hypothesis by observing the foraging choices of larvae of two omnivorous coccinellid species: Coccinella septempunctata L. and Hippodamia variegata (Goeze) (Coleoptera: Coccinellidae), following a diet history of prey, pollen or a mixed diet of both food types. Results showed an asymmetrical tendency of C. septempunctata larvae to complement their previous diet with unfamiliar food: larvae allocated more time to pollen feeding, but not to prey, when each of the foods was previously absent from their diet. Study results have important implications for the use of plant-provided food supplements to enhance biological control by these omnivorous consumers.     

The use of mosses in modern pollen studies at Morton Lochs,Fife

Summary

Samples of moss were collected each month between April 1980 and April 1983 from three sites within a small woodland glade at Morton Lochs National Nature Reserve, Tayport, Fife. Variations occured in the amount and range of modern pollen and spores in the moss samples from month to month and from year to year. In particular, lower numbers and a more restricted range of taxa were found in samples collected during winter months. This casts doubt on the assumptions that moss samples contain several years' accumulation of pollen and spores and that winter is the best time of year for collecting moss samples for modern pollen sudies.     

Influence of predator density,diet and living substrate on developmental fitness of Orius laevigatus

Mass rearing of Orius laevigatus on non‐insect foods could substantially increase the cost‐effectiveness of the production of this biological control agent which is largely based on the use of expensive eggs of the Mediterranean flour moth Ephestia kuehniella. In this study, the effect of substrate quality and predator density on nymphal development of O. laevigatus fed on E. kuehniella eggs, honeybee pollen or an egg yolk based artificial diet was assessed using several types of substrates as shelter materials in the rearing containers (wax paper, bean pod or no extra substrate). In general, E. kuehniella eggs proved to be a nutritionally superior food compared to pollen and artificial diet. Pollen supported nymphal development of O. laevigatus better than the artificial diet. Overall, increasing nymphal density resulted in higher mortality, which may be due in part to cannibalism. The addition of a bean pod compensated for the nutritionally suboptimal artificial, but had a negative effect when O. laevigatus was fed on pollen. The non‐insect foods tested could not adequately replace lepidopteran eggs as a food source for O. laevigatus but they may be useful as an alternative food or in a part of the rearing process.     

Effects of contact kairomone and experience on initial giving-up time

Reproduction and longevity of the anthocorid predators Orius laevigatus (Fieber) and Orius albidipennis (Reuter) (Heteroptera: Anthocoridae) were studied under controlled conditions in the laboratory. Three different diets were tested: eggs of the Mediterranean flour moth. Ephestia kuehniella Zeller, E. kuehniella eggs plus pollen, and pollen only. Small rooted plants of Spanish pepper (Capsicum annuum L. cv. Creta, long red) served as oviposition substrate and moisture source. In all treatments, total fecundity, oviposition period and female longevity of O. laevigatus were greater than that of O. albidipennis. When a diet of E. kuehniella eggs was supplemented with pollen, total fecundity of O. albidipennis was increased by about 40%. Female O. albidipennis fed only pollen laid five times less eggs than those fed flour moth eggs and pollen; also, longevity of females was shorter when only pollen was offered as food. Fecundity and longevity of O. laevigatus were not influenced when supplementing a diet of E. kuehniella eggs with pollen. Females of O. laevigatus receiving only pollen reduced egg production by about 60% but had a similar longevity as those receiving a diet including flour moth eggs. In either species, preoviposition period and egg hatch were not affected by diet. The ability of both anthocorids to use pollen as an alternative or additional food is discussed in relation to their practical use in integrated control programmes.     

Landscape distribution of food and nesting sites affect larval diet and nest size,but not abundance of Osmia bicornis

Habitat fragmentation is a major threat for beneficial organisms and the ecosystem services they provide. Multiple‐habitat users such as wild bees depend on both nesting and foraging habitat. Thus, they may be affected by the fragmentation of at least two habitat types. We investigated the effects of landscape‐scale amount of and patch isolation from both nesting habitat (woody plants) and foraging habitat (specific pollen sources) on the abundance and diet of Osmia bicornis L. Trap‐nests of O. bicornis were studied in 30 agricultural landscapes of the Swiss Plateau. Nesting and foraging habitats were mapped in a radius of 500 m around the sites. Pollen composition of larval diet changed as isolation to the main pollen source, Ranunculus, increased, suggesting that O. bicornis adapted its foraging strategy in function of the nest proximity to main pollen sources. Abundance of O. bicornis was neither related to isolation or amount of nesting habitat nor to isolation or abundance of food plants. Surprisingly, nests of O. bicornis contained fewer larvae in sites at forest edge compared to isolated sites, possibly due to higher parasitism risk. This study indicates that O. bicornis can nest in a variety of situations by compensating scarcity of its main larval food by exploiting alternative food sources.     

Gastrointestinal pH measurement in rats: influence of the microbial flora, diet and fasting

The pH of the rat intestinal tract was decreased by the presence of a microbial flora, but its influence in the forestomach is less clear. Stomach pH values varied according to the amount of food present at the time of measurement. Fasting increased the pH of the gastrointestinal tract in conventional rats but had little effect in germfree rats. In the conventional rat, feeding a purified diet compared with a commercial diet resulted in a lower pH in the forestomach and a higher pH in the caecal contents. Magnesium trisilicate promoted gastric emptying in conventional rats and its antacid effect was observed only in the caecum and colon.     

Performance of Amblyseius herbicolus on broad mites and on castor bean and sunnhemp pollen

Amblyseius herbicolus (Banks) is found associated with broad mites Polyphagotarsonemus latus in crops such as chili pepper in Brazil. The species has a potential for controlling P. latus, but little is known about its development and reproduction on this pest as well as on other food sources. We studied biological, reproductive and life table parameters of A. herbicolus on three different diets: broad mites, castor bean pollen (Ricinus communis) and sunnhemp pollen (Crotalaria juncea). The predator was able to develop and reproduce on all diets. However, its intrinsic growth rate was higher on the diet of broad mites or on castor bean pollen than on sunnhemp pollen. Differences among pollen species may be due to their nutritional content. Feeding on alternative food such as pollen can facilitate the predator’s mass rearing and maintain its population on crops when prey is absent or scarce. Other strategies of using pollen to sustain predator population and reduce pest damage are discussed.     

Bryophyte use by an insect herbivore: does the crane‐fly Tipula montana select food to maximise growth?

1. Growth rates of immature invertebrates can be of profound importance to subsequent reproductive success in the adult stage. If diet selection in herbivores is a principal means of maximising growth and rate of development, individuals should select food of the highest quality. 2. If disparities are found between performance and preference, these may be the result of individuals balancing nutritional gain against other demands on their behaviour, such as a need for shelter. The responses of the crane‐fly herbivore Tipula montana Curtis (Diptera: Tipulidae) to a range of moss genera from an upland environment were investigated to determine whether diet selection was determined by food quality alone, as measured by its effect on larval growth and survival. 3. Larvae were reared individually on single moss genus diets, and their growth, development, and survival were measured. Each of the mosses supported growth and development although the mean weights achieved differed by a factor of two between food genera. In two‐choice preference experiments, individuals broadly chose bryophyte foods as expected from their quality. One notable exception was the moss Pleurozium schreberi, which gave the best growth performance but was among the least preferred. 4. The two methods of assessing preference gave different results: observations of larvae showed relatively greater selection for dense mosses than faecal pellet analysis. A strong dietary preference for an angiosperm, the sedge Carex bigelowii, over all mosses supported the interpretation that crane‐fly larvae benefit from bryophytes as a refuge, and that this factor may override dietary quality.