1. Phengaris butterflies are obligatory social parasites of Myrmica ants. Early research suggested that there is a different Myrmica host species for each of the five European Phengaris social ...parasites, but more recent studies have shown that this was an oversimplification. 2. The pattern of host ant specificity within a Phengaris teleius metapopulation from southern Poland is reported. A combination of studying the frequency distribution of Phengaris occurrence and morphometrics on adult butterflies were used to test whether use of different host species is reflected in larval development. 3. Phengaris teleius larvae were found to survive in colonies of four Myrmica species: M. scabrinodis, M. rubra, M. ruginodis, and M. rugulosa. Myrmica scabrinodis was the most abundant species under the host plant but the percentage of infested nests was similar to other host ant species at two sites and lower in comparison to nests of M. rubra and M. ruginodis at the other two sites. Morphometric measurements of adult butterflies reared by wild colonies of M. scabrinodis and M. ruginodis showed that wing size and number of wing spots were slightly greater for adults eclosing from nests of M. ruginodis. 4. Our results suggest that P. teleius in the populations studied is less specialised than previously suggested. The results are consistent with the hypothesis that P. teleius is expected to be the least specific of the European Phengaris species, as it has the largest and best defended fourth-instar caterpillars and, as a predatory species, it spends less time in the central larval chambers of the host colonies. The fact that individuals reared by M. ruginodis had wider hind wings may suggest that P. teleius had better access to resources in M. ruginodis than in M. scabrinodis colonies.
Summary
Studying fungal biodiversity using data generated from Illumina MiSeq sequencing platforms poses a number of bioinformatic challenges with the analysis typically involving a large number of ...tools for each analytical step from quality filtering to generating identified operational taxonomic unit (OTU) abundance tables.
Here, we introduce PIPITS, an open‐source stand‐alone suite of software for automated processing of Illumina MiSeq sequences for fungal community analysis. PIPITS exploits a number of state of the art applications to process paired‐end reads from quality filtering to producing OTU abundance tables.
We provide detailed descriptions of the pipeline and show its utility in the analysis of 9 396 092 sequences generated on the MiSeq platform from Illumina MiSeq.
PIPITS is the first automated bioinformatics pipeline dedicated for fungal ITS sequences which incorporates ITSx to extract subregions of ITS and exploits the latest RDP Classifier to classify sequences against the curated UNITE fungal data set.
Oak galls are spectacular extended phenotypes of gallwasp genes in host oak tissues and have evolved complex morphologies that serve, in part, to exclude parasitoid natural enemies. Parasitoids and ...their insect herbivore hosts have coevolved to produce diverse communities comprising about a third of all animal species. The factors structuring these communities, however, remain poorly understood. An emerging theme in community ecology is the need to consider the effects of host traits, shaped by both natural selection and phylogenetic history, on associated communities of natural enemies. Here we examine the impact of host traits and phylogenetic relatedness on 48 ecologically closed and species-rich communities of parasitoids attacking gall-inducing wasps on oaks. Gallwasps induce the development of spectacular and structurally complex galls whose species- and generation-specific morphologies are the extended phenotypes of gallwasp genes. All the associated natural enemies attack their concealed hosts through gall tissues, and several structural gall traits have been shown to enhance defence against parasitoid attack. Here we explore the significance of these and other host traits in predicting variation in parasitoid community structure across gallwasp species. In particular, we test the "Enemy Hypothesis," which predicts that galls with similar morphology will exclude similar sets of parasitoids and therefore have similar parasitoid communities. Having controlled for phylogenetic patterning in host traits and communities, we found significant correlations between parasitoid community structure and several gall structural traits (toughness, hairiness, stickiness), supporting the Enemy Hypothesis. Parasitoid community structure was also consistently predicted by components of the hosts' spatiotemporal niche, particularly host oak taxonomy and gall location (e.g., leaf versus bud versus seed). The combined explanatory power of structural and spatiotemporal traits on community structure can be high, reaching 62% in one analysis. The observed patterns derive mainly from partial niche specialisation of highly generalist parasitoids with broad host ranges (>20 hosts), rather than strict separation of enemies with narrower host ranges, and so may contribute to maintenance of the richness of generalist parasitoids in gallwasp communities. Though evolutionary escape from parasitoids might most effectively be achieved via changes in host oak taxon, extreme conservatism in this trait for gallwasps suggests that selection is more likely to have acted on gall morphology and location. Any escape from parasitoids associated with evolutionary shifts in these traits has probably only been transient, however, due to subsequent recruitment of parasitoid species already attacking other host galls with similar trait combinations.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The communities associated with the invading gall wasp Andricus quercuscalicis vary considerably in species richness and species composition throughout its native and invaded ranges. Seventeen ...species of inquilines and parasitoids were identified as coinhabitants of the agamic galls of Andricus quercuscalicis throughout Europe. The life-histories of the parasitoid species are described; one is a solitary endoparasitoid, one a gregarious endoparasitoid and the remainder are solitary ectoparasitoids. A tortricid moth which develops as an inquiline in the agamic galls of A. quercuscalicis kills the gall causer; this is the first description of such an interaction between moths and cynipids. While some parasitoid species appear to be restricted in their attack to the native range of A. quercuscalicis, others were found throughout the range. Geographic variation in the species composition and the possible role of the invasion history of the host are discussed. Food web parameters calculated for the community from the native range and six regions across the invaded range appear to be correlated with the residence time of the invading host, in accordance with studies of successional communities. However, it might be impossible to separate effects of time from those of species richness.
•AOD symptomatic trees have fewer fine root tips than asymptomatic trees.•Long distance ectomycorrhizal exploration types are more abundant on AOD asymptomatic trees.•Ectomycorrhizal diversity and ...composition are not altered by the AOD symptom status of trees.•The composition of ectomycorrhizal communities is related to levels of soil C:N ratios, N and Al.•Above-ground symptoms of AOD (i.e. stem lesions and Agrilus biguttatus exit holes) are related to the frequency of live root tips.
Acute Oak Decline (AOD) is a decline-disease that has distinctive symptoms and poses a serious threat to oak. Our understanding of the causal factors of AOD remains poor but it is likely that multiple biotic and abiotic factors contribute to a deterioration in oak condition. There is evidence that indications of above-ground tree health status are frequently reflected below-ground in roots and associated ectomycorrhizal (ECM) fungal communities. However, no study has yet explored these potential relationships specifically in AOD affected trees. In this study, we compare the composition and range of functional exploration types of ECM communities associated with AOD symptomatic oak trees and with AOD asymptomatic trees in three oak-dominated woodlands in southern England. We additionally assess the abundance of fine root tips in surface soils beneath AOD symptomatic and asymptomatic trees and consider soil physico-chemical effects on ECM communities. The frequency of fine root tips was found to be significantly higher on asymptomatic compared with symptomatic trees in two of the three woodlands studied and long-distance ECM exploration types had a weak positive association with AOD asymptomatic trees. ECM diversity and composition were, however, unaffected by tree symptom status and were not related to the frequency of fine root tips. ECM diversity and compositional (but not exploration type) differences were evident only between the different woodlands and this was related to a small number of soil chemistry variables. This study revealed a relationship between the above-ground symptoms of AOD (i.e. stem lesions and Agrilus biguttatus exit holes) and the frequency of live root tips, providing a potential additional diagnostic tool of trees in decline and highlighting the importance of considering belowground rhizosphere microbiome communities.
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Bumblebees are valuable pollinators of numerous wild and cultivated plants. They can forage on variable pollen resources. As some pollen species lack particular nutrients or have global low ...nutritional quality, it has been suggested that bumblebees mix their pollen incomes to ensure a global balanced diet. The hypothesis that a mixed pollen diet better supports bumblebee colony development than a single pollen diet has been poorly explored.
We compared the impact of mono‐, di‐ and trifloral diets on microcolony development of Bombus terrestris using three pollen resources with different nutrient contents (Cytisus scoparius, Erica sp. and Sorbus aucuparia) as well as their mixes. Nine parameters (e.g. pollen efficacy: total weight of larvae/total weight of pollen collection) were used to compare the microcolony performances. Moreover, we measured the influence of the pollen diversity and nutritional composition on relevant parameters.
We showed that microcolonies can potentially better develop on mixed pollen diets, but single pollen diet can also be as good as mixed pollen diet. Moreover, the sterol concentration appeared as a key factor to establish the impact of a pollen diet on the bumblebee colony development.
This study reveals that diverse pollen diet does not necessary equate with good colony development and supports the importance of selecting floral resources by considering their nutrient contents for bee conservation management.
Pollinator declines caused by forage habitat loss threaten insect pollination services. Pollinating insects depend on adequate floral resources, and their ability to track these resources. ...Variability of these resources and the effect on insect foraging choice is poorly understood.
We record patterns of visitation to six wildflower species and test the hypotheses that: pollinators preferentially visit the most rewarding flowers; nectar diurnal variations affect foraging preferences; pollinators respond most strongly to nectar rewards.
Nectar volume and sugar concentration were negatively correlated within plant species over time of day where greater concentration and lower volume was evident in the afternoon, but this did not correspond to pollinator visitation. Both floral abundance and nectar quality (total sugar per inflorescence) positively affect insect visitation. For some foragers, the positive effects of high‐quality rewards were only evident when floral abundance was high (>50 inflorescences per patch), perhaps reflecting the low probability of pollinators detecting scarce rewards. Pollen quality (total protein per inflorescence) was negatively related to visitation of Apis mellifera and Bombus pascuorum.
Fewer pollinators visiting flowers of higher pollen quality could reflect plant allocation trade‐offs or the presence of secondary metabolites in pollen, meaning pollen foraging is likely affected by factors other than protein concentration. Nectar rather than pollen appeared to be the main driver of floral choice by insects in this system.
Conservation schemes for bees in farmland or gardens might benefit from ensuring that rewarding plant species are present at high density and/or are aggregated in space.
To date there have been only limited fine-scale investigations into the molecular ecology of the European hoverfly, Microdon mutabilis, due to the paucity of available polymorphic markers. We ...describe the development of primers amplifying five novel microsatellite loci using next-generation sequencing (454) and three previously undescribed M. mutabilis microsatellite loci using enrichments. In hoverflies from a population in Ireland, the number of alleles per locus ranged from 2 to 16, and the observed heterozygosity ranged between 0.26 and 0.97
The larva of the hoverfly Microdon mutabilis is a specialist social parasite of the ant Formica lemani that is adapted to local groups of F. lemani colonies but mal-adapted to colonies of the same ...species situated only a few hundred meters away. At a study site in Ireland, F. lemani shares its habitat with four other ant species. All nest under stones, making the oviposition choice by M. mutabilis females crucial to offspring survival. In this study, we tested the hypothesis that, as an extreme specialist, M. mutabilis should respond to cues derived from its host rather than from its microenvironment, a phenomenon that has hitherto only been addressed in the context of herbivorous insects and their parasitoids. In behavioral assays, M. mutabilis females reacted to volatiles from F. lemani colonies by extending their ovipositors, presumably probing for an oviposition substrate. This behavior was not observed toward negative controls or volatiles from colonies of Myrmica scabrinodis, the host ant of the closely related Microdon myrmicae. Coupled gas chromatography-electroantennography (GC-EAG) that used antennal preparations of M. mutabilis located a single physiologically active compound within an extract of heads of F. lemani workers. Coupled GC-mass spectrometry (GC-MS) tentatively identified the compound as a methylated methylsalicylate. GC co-injection of the extract with authentic samples showed that of the four possible isomers (methyl 3-, 4-, 5-, and 6-methylsalicylate), only methyl 6-methylsalicylate co-eluted with the EAG-active peak. Furthermore, the response to methyl 6-methylsalicylate was four times higher than to those of the other isomers. Coupled GC-EAG and GC-MS also revealed physiological responses to two constituents, 3-octanone and 3-octanol, of the M. scabrinodis alarm pheromone. However, the behavioral trials did not reveal any behavior that could be attributed to these compounds. Results are discussed in the context of four phases of host location behavior, and of the characteristics, which volatile cues should provide to be useful for an extreme specialist such as M. mutabilis.
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