Euschistus heros mass rearing technique for the multiplication of Telenomus podisi

The objective of this work was to improve the mass rearing technique of Euschistus heros in laboratory. Nymphs and adults were reared at densities 100, 200, 300 and 400 eggs per Petri dish (9 cm diameter), and at 50, 100, 150 and 200 couples per rearing cages (900 mL), respectively. Survival rate of immature stages and survivorship and reproduction of adults were determinated. Survivorship of nymph to adult was the highest (89%) at density 100 eggs per dish. Adult survivorship was independent of density, and 100 couples per cage were the best to improve quality of the produced progeny. In these conditions, fecundity was 160.8±9.28 eggs per female, and a total of 8,950±456 eggs per cage per month was produced. Two hundred couples per cage showed a negative effect on reproduction, which decreased to 65%. With this technique, a colony of 35 cages with 100 couples per cage yields about 313.3 thousands eggs per month, which is enough to supply the egg parasitoid Telenomus podisi to colonize about 35 ha of soybean field.

The assessment of reproductive success of queens in ants and other social insects

Recently considerable research has focused on the causes of evolution of multiple-queen (polygynous) colonies. In order to better understand the factors which may have led to these polygynous associations it is vital to compare the reproductive success of queens in monogynous (one queen per colony) and polygynous colonies as well as the relative fitness of queens in polygynous colonies. This paper addresses the difficulties arising from such comparisons and their implications with regard to the methods commonly used to assess reproductive success in queens. The relative reproductive success of queens in monogynous and polygynous colonies is commonly assessed by comparing the relative number of reproductives they produce during a single reproductive season. However, shift in queen number seems to be only one aspect of a profound shift in social structure and reproductive strategy that constitutes, in effect, a ''polygyny syndrome''. For example, female reproductives produced in polygynous colonies frequently use a different mode of colony founding, which in turn affects the probability of their survival. Furthermore, queens from monogynous and polygynous colonies frequently differ in their life-span and the number of sexual broods they produce. As a result, the reproductive success of queens in monogynous and polygynous colonies may not be directly related to the relative number of sexuals they produce during a single reproductive season.

Water-filtered infrared-A radiation (wIRA) is not implicated in cellular degeneration of human skin.

BACKGROUND: Excessive exposure to solar ultraviolet radiation is involved in the complex biologic process of cutaneous aging. Wavelengths in the ultraviolet-A and -B range (UV-A and UV-B) have been shown to be responsible for the induction of proteases, e. g. the collagenase matrix metalloproteinase 1 (MMP-1), which are related to cell aging. As devices emitting longer wavelengths are widely used in therapeutic and cosmetic interventions and as the induction of MMP-1 by water-filtered infrared-A (wIRA) had been discussed, it was of interest to assess effects of wIRA on the cellular and molecular level known to be possibly involved in cutaneous degeneration. OBJECTIVES: Investigation of the biological implications of widely used water-filtered infrared-A (wIRA) radiators for clinical use on human skin fibroblasts assessed by MMP-1 gene expression (MMP-1 messenger ribonucleic acid (mRNA) expression).Methods: Human skin fibroblasts were irradiated with approximately 88% wIRA (780-1400 nm) and 12% red light (RL, 665-780 nm) with 380 mW/cm(2) wIRA(+RL) (333 mW/cm(2) wIRA) on the one hand and for comparison with UV-A (330-400 nm, mainly UV-A1) and a small amount of blue light (BL, 400-450 nm) with 28 mW/cm(2) UV-A(+BL) on the other hand. Survival curves were established by colony forming ability after single exposures between 15 minutes and 8 hours to wIRA(+RL) (340-10880 J/cm(2) wIRA(+RL), 300-9600 J/cm(2) wIRA) or 15-45 minutes to UV-A(+BL) (25-75 J/cm(2) UV-A(+BL)). Both conventional Reverse Transcriptase Polymerase Chain Reaction (RT-PCR) and quantitative real-time RT-PCR techniques were used to determine the induction of MMP-1 mRNA at two physiologic temperatures for skin fibroblasts (30 degrees C and 37 degrees C) in single exposure regimens (15-60 minutes wIRA(+RL), 340-1360 J/cm(2) wIRA(+RL), 300-1200 J/cm(2) wIRA; 30 minutes UV-A(+BL), 50 J/cm(2) UV-A(+BL)) and in addition at 30 degrees C in a repeated exposure protocol (up to 10 times 15 minutes wIRA(+RL) with 340 J/cm(2) wIRA(+RL), 300 J/cm(2) wIRA at each time). RESULTS: Single exposure of cultured human dermal fibroblasts to UV-A(+BL) radiation yielded a very high increase in MMP-1 mRNA expression (11 +/-1 fold expression for RT-PCR and 76 +/-2 fold expression for real-time RT-PCR both at 30 degrees C, 75 +/-1 fold expression for real-time RT-PCR at 37 degrees C) and a dose-dependent decrease in cell survival. In contrast, wIRA(+RL) did not produce cell death and did not induce a systematic increase in MMP-1 mRNA expression (less than twofold expression, within the laboratory range of fluctuation) detectable with the sensitive methods applied. Additionally, repeated exposure of human skin fibroblasts to wIRA(+RL) did not induce MMP-1 mRNA expression systematically (less than twofold expression by up to 10 consecutive wIRA(+RL) exposures and analysis with real-time RT-PCR). CONCLUSIONS: wIRA(+RL) even at the investigated disproportionally high irradiances does not induce cell death or a systematic increase of MMP-1 mRNA expression, both of which can be easily induced by UV-A radiation. Furthermore, these results support previous findings of in vivo investigations on collagenase induction by UV-A but not wIRA and show that infrared-A with appropriate irradiances does not seem to be involved in MMP-1 mediated photoaging of the skin. As suggested by previously published studies wIRA could even be implicated in a protective manner.

Awakening dormant haematopoietic stem cells.

Haematopoietic stem cells (HSCs) in mouse bone marrow are located in specialized niches as single cells. During homeostasis, signals from this environment keep some HSCs dormant, which preserves long-term self-renewal potential, while other HSCs actively self renew to maintain haematopoiesis. In response to haematopoietic stress, dormant HSCs become activated and rapidly replenish the haematopoietic system. Interestingly, three factors - granulocyte colony-stimulating factor, interferon-alpha and arsenic trioxide - have been shown to efficiently activate dormant stem cells and thereby could break their resistance to anti-proliferative chemotherapeutics. Thus, we propose that two-step strategies could target resistant leukaemic stem cells by priming tumours with activators of dormancy followed by chemotherapy or targeted therapies.

Variable queen number in ant colonies: no impact on queen turnover, inbreeding, and population genetic differentiation in the ant Formica selysi.

Variation in queen number alters the genetic structure of social insect colonies, which in turn affects patterns of kin-selected conflict and cooperation. Theory suggests that shifts from single- to multiple-queen colonies are often associated with other changes in the breeding system, such as higher queen turnover, more local mating, and restricted dispersal. These changes may restrict gene flow between the two types of colonies and it has been suggested that this might ultimately lead to sympatric speciation. We performed a detailed microsatellite analysis of a large population of the ant Formica selysi, which revealed extensive variation in social structure, with 71 colonies headed by a single queen and 41 by multiple queens. This polymorphism in social structure appeared stable over time, since little change in the number of queens per colony was detected over a five-year period. Apart from queen number, single- and multiple-queen colonies had very similar breeding systems. Queen turnover was absent or very low in both types of colonies. Single- and multiple-queen colonies exhibited very small but significant levels of inbreeding, which indicates a slight deviation from random mating at a local scale and suggests that a small proportion of queens mate with related males. For both types of colonies, there was very little genetic structuring above the level of the nest, with no sign of isolation by distance. These similarities in the breeding systems were associated with a complete lack of genetic differentiation between single- and multiple-queen colonies, which provides no support for the hypothesis that change in queen number leads to restricted gene flow between social forms. Overall, this study suggests that the higher rates of queen turnover, local mating, and population structuring that are often associated with multiple-queen colonies do not appear when single- and multiple-queen colonies still coexist within the same population, but build up over time in populations consisting mostly of multiple-queen colonies.

Population genetic structure in the native and introduced range of the Argentine ant/

SUMMARY : The evolution of animal societies, where some individuals forego their own reproductive opportunities to help others to reproduce, poses an evolutionary paradox that can be traced back to Darwin. Altruism may evolve through kin selection when the donor and recipient of altruistic acts are related to each other. In social insects, workers are generally highly related to the brood they rear when colonies are headed by a single queen. Yet some ants have an extraordinary social organization, called unicoloniality, whereby individuals from separate nests mix freely to form large supercolonies, which in some cases extend over hundreds of km. These supercolonies are characterised by a high number of queens (polygyny) and an absence of clear colony boundaries. This type of social organization represents an evolutionary paradox because relatedness between nestmates is effectively zero. In such conditions, kin selection cannot account for the evolution of reproductive altruism. Moreover, unicoloniality is thought to be unstable over time, because workers that can no longer aid close relatives may evolve more selfish strategies. The Argentine ant (Linepithema humile) is a highly invasive species listed among the hundred world's worst invaders by the UICN. Native from South America, L. humile has been accidentally introduced throughout the world. Native populations have been described as noninvasive with a family-based organization. In contrast, within its introduction range, they form unicolonial supercolonies that contain numerous nests without intraspecific aggression. The development of such unicolonial populations has been explained as a direct consequence of the ant's introduction into a new habitat, favouring a transition from family-based to open colonies. To determine if the social structure of the Argentine ant is fundamentally different between the native and the introduced range, we studied genetically and behaviourally native and introduced populations of L. humile over different geographic scales. Our results clearly indicated that there are no fundamental differences in the social organisation of the Argentine ant between the two ranges. Our investigations revealed that, contrary to previous claims, native populations have a unicolonial social organisation very similar to that observed in the introduced range. Consequently, the unicolonial social structure of the Argentine ant does not stem from a shift in social organization associated with introduction into new habitats but evolved in the native range and is likely a stable, evolutionarily ancient adaptation to the local environment. Our study on native populations of L. humile also gave important insight in the comprehension of the evolution of unicoloniality in the Argentine ant. Native supercolonies are relatively small compared to introduced ones and may co-habit in a same population. These supercolonies are genetically highly differentiated leading to a significant relatedness among nestmate workers when the different supercolonies of a population are taken as a reference population. This provides the necessary conditions for loin selection to operate. Furthermore, we examined a native population over time, which revealed a high supercolony extinction rate. If more competitive supercolonies are more likely to survive or replace other supercolonies, a subtle dynamical process between the spread of selfish traits within supercolony and the selective elimination of supercolonies with such traits may allow a stable equilibrium and the persistence of unicoloniality over time. Finally, a worldwide study of the Argentine ant showed that the introduced supercolonies originate from numerous independent introduction events. In conclusion, the success of the Argentine ant does not stem from a shift in social organization associated with its introduction into new habitats, but is most probably explained by the intrinsic characteristics developed in its native range. RESUME : L'altruisme de reproduction où certains individus renoncent à leur propre reproduction pour aider d'autres individus à se reproduire constitue l'un des plus grand paradoxe de l'évolution. En effet, comment expliquer l'évolution de comportements qui tendent à augmenter les chances de survie et le succès reproductif d'autres individus, alors que ces actes diminuent l'aptitude de leurs auteurs ? La théorie de la sélection de parentèle permet de résoudre ce problème. Cette théorie stipule qu'en aidant de proches parents à se reproduire, les individus peuvent promouvoir indirectement la transmission de copies de leurs propres gènes à la génération suivante. Chez les insectes sociaux, l'altruisme des ouvrières s'explique par la théorie de sélection de parentèle lorsque les colonies sont monogynes (constituées d'une seule reine) puisque les ouvrières sont fortement apparentées aux couvains dont elles s'occupent. Par contre, les espèces dites unicoloniales, dont les colonies forment des réseaux de nids appelés supercolonies, représentent toujours un paradoxe pour les théories de l'évolution puisque l'apparentement entre les différents individus d'un nid est nulle. De plus, l'unicolonialité ne devrait pas être stable sur le long terme parce que les ouvrières qui ne s'occupent plus de leur apparentés devraient développer des stratégies plus égoïstes au cours du temps. La fourmi d'Argentine (Linepithema humile) est une espèce invasive ayant un impact considérable sur son environnement. Originaire d'Amérique du Sud, elle a été introduite dans pratiquement toutes les régions du monde dont le climat est de type méditerranéen. Son incroyable succès invasif s'explique par sa structure sociale unicoloniale observée dans chacun des pays où elle a été introduite. Par contre, les rares études effectuées en Argentine ont suggéré que la fourmi d'Argentine n'était pas unicoloniale dans son aire native. L'unicolonialité chez la fourmi d'Argentine était donc considéré comme une conséquence de son introduction dans de nouveaux environnements. Durant cette thèse, nous avons vérifié si la structure sociale de cette espèce différait fondamentalement entre l'aire native et introduite. Pour cela, nous avons étudié, à différentes échelles géographiques, des populations introduites et argentines avec une approche génétique et comportementale. L'ensemble de nos résultats montrent que les différences entre les deux structure sociales ne sont pas aussi importantes que ce que l'on imaginait. Les populations natives sont aussi constituées de réseaux de nids coopérants. La taille de ses supercolonies est toutefois bien moins importante en Argentine et il n'est pas rare de trouver plusieurs supercolonies cohabitantes dans une même population. Nous avons démontré que ces réseaux de nids étaient constitués d'individus qui sont plus apparentés entre eux qu'ils ne le sont avec les individus d'autres supercolonies, ainsi l'unicolonialité dans son aire d'origine ne représente pas un réel paradoxe pour les théories de l'évolution. Finalement nous avons étudié la même population en Argentine à six ans d'intervalle et avons constaté que les supercolonies avaient un taux de survie très faible ce qui pourrait expliquer la stabilité de l'unicolonialité au cours du temps. Si les supercolonies les plus compétitives survivent mieux que les supercolonies dans lesquelles apparaissent des traits égoïstes, on devrait alors observer une dynamique entre l'apparition de traits égoïstes et l'élimination des supercolonies dans lesquelles ces traits égoïstes évolueraient. Finalement, une étude mondiale nous a montré que les supercolonies étaient originaires de nombreux événements d'introductions indépendants. En conclusion, le succès invasif de la fourmi d'Argentine n'est donc pas dû à un changement de comportement associé à son introduction mais est lié aux caractéristiques qu'elle a développées en Argentine.

Molecular and social regulation of worker division of labour in fire ants.

Reproductive and worker division of labour (DOL) is a hallmark of social insect societies. Despite a long-standing interest in worker DOL, the molecular mechanisms regulating this process have only been investigated in detail in honey bees, and little is known about the regulatory mechanisms operating in other social insects. In the fire ant Solenopsis invicta, one of the most studied ant species, workers are permanently sterile and the tasks performed are modulated by the worker's internal state (age and size) and the outside environment (social environment), which potentially includes the effect of the queen presence through chemical communication via pheromones. However, the molecular mechanisms underpinning these processes are unknown. Using a whole-genome microarray platform, we characterized the molecular basis for worker DOL and we explored how a drastic change in the social environment (i.e. the sudden loss of the queen) affects global gene expression patterns of worker ants. We identified numerous genes differentially expressed between foraging and nonforaging workers in queenright colonies. With a few exceptions, these genes appear to be distinct from those involved in DOL in bees and wasps. Interestingly, after the queen was removed, foraging workers were no longer distinct from nonforaging workers at the transcriptomic level. Furthermore, few expression differences were detected between queenright and queenless workers when we did not consider the task performed. Thus, the social condition of the colony (queenless vs. queenright) appears to impact the molecular pathways underlying worker task performance, providing strong evidence for social regulation of DOL in S. invicta.

Venom alkaloid and cuticular hydrocarbon profiles are associated with social organization, queen fertility status, and queen genotype in the fire ant Solenopsis invicta.

Queens in social insect colonies advertise their presence in the colony to: a) attract workers' attention and care; b) gain acceptance by workers as replacement or supplemental reproductives; c) prevent reproductive development in nestmates. We analyzed the chemical content of whole body surface extracts of adult queens of different developmental and reproductive stages, and of adult workers from monogyne (single colony queen) and polygyne (multiple colony queens) forms of the fire ant Solenopsis invicta. We found that the composition of the most abundant components, venom alkaloids, differed between queens and workers, as well as between reproductive and non-reproductive queens. Additionally, workers of the two forms could be distinguished by alkaloid composition. Finally, sexually mature, non-reproductive queens from polygyne colonies differed in their proportions of cis-piperidine alkaloids, depending on their Gp-9 genotype, although the difference disappeared once they became functional reproductives. Among the unsaturated cuticular hydrocarbons characteristic of queens, there were differences in amounts of alkenes/alkadienes between non-reproductive polygyne queens of different Gp-9 genotypes, between non-reproductive and reproductive queens, and between polygyne and monogyne reproductive queens, with the amounts increasing at a relatively higher rate through reproductive ontogeny in queens bearing the Gp-9 b allele. Given that the genotype-specific piperidine differences reflect differences in rates of reproductive maturation between queens, we speculate that these abundant and unique compounds have been co-opted to serve in fertility signaling, while the cuticular hydrocarbons now play a complementary role in regulation of social organization by signaling queen Gp-9 genotype.

In conspectu prope totius urbis: an application of different visual methods at the ager Tarraconensis landscape

We present in this paper the results of the application of several visual methods on a group of locations, dated between VI and I centuries BC, of the ager Tarraconensis (Tarragona, Spain) a Hinterland of the roman colony of Tarraco. The difficulty in interpreting the diverse results in a combined way has been resolved by means of the use of statistical methods, such as Principal Components Analysis (PCA) and K-means clustering analysis. These methods have allowed us to carry out site classifications in function of the landscape's visual structure that contains them and of the visual relationships that could be given among them.

Concentration of Airborne Staphylococcus aureus (MRSA and MSSA), Total Bacteria, and Endotoxins in Pig Farms.

Pigs are very often colonized by Staphylococcus aureus and transmission of such pig-associated S. aureus to humans can cause serious medical, hygiene, and economic problems. The transmission route of zoonotic pathogens colonizing farm animals to humans is not well established and bioaerosols could play an important role. The aim of this study was to assess the potential occupational risk of working with S. aureus-colonized pigs in Switzerland. We estimated the airborne contamination by S. aureus in 37 pig farms (20 nursery and 17 fattening units; 25 in summer, 12 in winter). Quantification of total airborne bacterial DNA, airborne Staphylococcus sp. DNA, fungi, and airborne endotoxins was also performed. In this experiment, the presence of cultivable airborne methicillin-resistant S. aureus (MRSA) CC398 in a pig farm in Switzerland was reported for the first time. Airborne methicillin-sensitive S. aureus (MSSA) was found in ~30% of farms. The average airborne concentration of DNA copy number of total bacteria and Staphylococcus sp. measured by quantitative polymerase chain reaction was very high, respectively reaching values of 75 (± 28) × 10(7) and 35 (± 9.8) × 10(5) copy numbers m(-3) in summer and 96 (± 19) × 10(8) and 40 (± 12) × 10(6) copy numbers m(-3) in winter. Total mean airborne concentrations of endotoxins (1298 units of endotoxin m(-3)) and fungi (5707 colony-forming units m(-3)) exceeded the Swiss recommended values and were higher in winter than in summer. In conclusion, Swiss pig farmers will have to tackle a new emerging occupational risk, which could also have a strong impact on public health. The need to inform pig farmers about biological occupational risks is therefore crucial.

Population genomics of eusocial insects: the costs of a vertebrate-like effective population size

The evolution of reproductive division of labour and social life in social insects has lead to the emergence of several life-history traits and adaptations typical of larger organisms: social insect colonies can reach masses of several kilograms, they start reproducing only when they are several years old, and can live for decades. These features and the monopolization of reproduction by only one or few individuals in a colony should affect molecular evolution by reducing the effective population size. We tested this prediction by analysing genome-wide patterns of coding sequence polymorphism and divergence in eusocial vs. noneusocial insects based on newly generated RNA-seq data. We report very low amounts of genetic polymorphism and an elevated ratio of nonsynonymous to synonymous changes - a marker of the effective population size - in four distinct species of eusocial insects, which were more similar to vertebrates than to solitary insects regarding molecular evolutionary processes. Moreover, the ratio of nonsynonymous to synonymous substitutions was positively correlated with the level of social complexity across ant species. These results are fully consistent with the hypothesis of a reduced effective population size and an increased genetic load in eusocial insects, indicating that the evolution of social life has important consequences at both the genomic and population levels.

Identification and characterization of pathogenic Pestalotiopsis species to pecan tree in Brazil

The objective of this work was to characterize and cluster isolates of Pestalotiopsis species and to identify those that are pathogenic to pecan, based on morphological and molecular characters. Pestalotiopsis spp. isolates were identified by sequencing the internal transcribed spacer (ITS) and β?tubulin regions. Identification methods were compared to indicate the key morphological characters for species characterization. Thirteen isolates were used for the pathogenicity tests. Morphological characterization was performed using the following variables: mycelial growth rate, sporulation, colony pigmentation, and conidial length and width. Ten pathogenic isolates were identified, three as -tubulin regions. Identification methods were compared to indicate the key morphological characters for species characterization. Thirteen isolates were used for the pathogenicity tests. Morphological characterization was performed using the following variables: mycelial growth rate, sporulation, colony pigmentation, and conidial length and width. Ten pathogenic isolates were identified, three as Pestalotiopsis clavispora and three as P. cocculi. The other isolates remained as an undefined species. The morphological characters were efficient for an initial separation of the isolates, which were grouped according to differences at species level, mainly colony diameter, which was identified as an important morphological describer. Beta-tubulin gene sequencing was less informative than the ITS region sequencing for species identification.

Genetic components to caste allocation in a multiple-queen ant species.

Reproductive division of labor and the coexistence of distinct castes are hallmarks of insect societies. In social insect species with multiple queens per colony, the fitness of nestmate queens directly depends on the process of caste allocation (i.e., the relative investment in queen, sterile worker and male production). The aim of this study is to investigate the genetic components to the process of caste allocation in a multiple-queen ant species. We conducted controlled crosses in the Argentine ant Linepithema humile and established single-queen colonies to identify maternal and paternal family effects on the relative production of new queens, workers, and males. There were significant effects of parental genetic backgrounds on various aspects of caste allocation: the paternal lineage affected the proportion of queens and workers produced whereas the proportions of queens and males, and females and males were influenced by the interaction between parental lineages. In addition to revealing nonadditive genetic effects on female caste determination in a multiple-queen ant species, this study reveals strong genetic compatibility effects between parental genomes on caste allocation components.

G-CSF-induced remission in two cases of acute myeloid leukemia.

We report on two elderly patients with newly diagnosed acute myeloid leukemia (AML) who were treated in palliative intention because of comorbidities and intermediate or poor risk cytogenetics. Both received G-CSF to reduce the risk of infection related to neutropenia. Interestingly, one patient achieved a full hematological remission and the other a peripheral remission with dramatic reduction of the bone marrow blast count. Although a direct therapeutic effect of myeloid growth factors seems to be unusual in AML, the use of G-CSF or GM-CSF may be recommended in patients such as elderly patients who are not suited for intensive chemotherapy.

Sex ratio and Wolbachia infection in the ant Formica exsecta.

Sex allocation data in social Hymenoptera provide some of the best tests of kin selection, parent-offspring conflict and sex ratio theories. However, these studies critically depend on controlling for confounding ecological factors and on identifying all parties that potentially manipulate colony sex ratio. It has been suggested that maternally inherited parasites may influence sex allocation in social Hymenoptera. If the parasites can influence sex allocation, infected colonies are predicted to invest more resources in females than non-infected colonies, because the parasites are transmitted through females but not males. Prime candidates for such sex ratio manipulation are Wolbachia, because these cytoplasmically transmitted bacteria have been shown to affect the sex ratio of host arthropods by cytoplasmic incompatibility, parthenogenesis, male-killing and feminization. In this study, we tested whether Wolbachia infection is associated with colony sex ratio in two populations of the ant Formica exsecta that have been the subject of extensive sex ratio studies. In these populations colonies specialize in the production of one sex or the other. We found that almost all F. exsecta colonies in both populations are infected with Wolbachia. However, in neither population did we find a significant association in the predicted direction between the prevalence of Wolbachia and colony sex ratio. In particular, colonies with a higher proportion of infected workers did not produce more females. Hence, we conclude that Wolbachia does not seem to alter the sex ratio of its hosts as a means to increase transmission rate in these two populations of ants.