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Highlights: [•] Rapid bootstrapping can provide inflated support values for polytomies. [•] The SH-like aLRT outperforms the bootstrap when applied to polytomies. [•] The 70% bootstrap cutoff does not equate to a 5% error rate. [•] Rapid bootstrapping with GTRCAT can generate values with very low precision. [Copyright &y& Elsevier]

Abstract: A supermatrix of 272 terminals from Rubiaceae tribe Spermacoceae that were scored for up to 10 gene regions (two nrDNA, eight plastid) was used as an empirical example to quantify sources of error in heuristic parametric (Bayesian MCMC and maximum likelihood) phylogenetic analyses. The supermatrix includes dramatic disparities in which terminals were sampled for which gene regions. The sources of error examined include poor quality tree searches, requiring a single fully resolved optimal tree, undersampling-within-replicates and frequency-within-replicates bootstrap artifacts, and extrapolation from one character partition to another such that synapomorphies that would only be ambiguously optimized by parsimony are optimized with high probability by parametric methods. Four of our conclusions are as follows. (1) The resolution and support provided by parametric methods for clades that lack unambiguously optimized (by parsimony) synapomorphies are less robust to the addition of terminals and characters than those clades that have unambiguously optimized synapomorphies. (2) Those tree-search methods which can create phylogenetic artifacts (frequency-within-replicates resampling, undersampling-within-replicates resampling, requiring a single fully resolved optimal tree, non-independent resampling among replicates) provide the greatest resolution and support irrespective of whether that resolution or support is corroborated by more conservative and better justified methods. (3) Partitioning data matrices cannot be relied upon to consistently obviate potentially dubious resolution and support caused by missing-data artifacts in likelihood analyses when the models require linked branch lengths among partitions. (4) Undersampling-within-replicates and frequency-within-replicates resampling artifacts are not unique to parsimony and should be accounted for in likelihood analyses by allowing multiple equally likely trees to be saved within each resampling pseudoreplicate and applying the strict-consensus bootstrap rather than the frequency-within-replicates bootstrap. [Copyright &y& Elsevier]

Exotic plants can negatively impact the fitness of native plants by changing the behavior of flower visitors and thus affecting pollen transfer. The presence of an exotic plant may decrease the visitation rate to native plants and thus increase pollen limitation. Flower visitors may also switch between exotic and native plants and if pollen from an exotic plant is transferred to native plant stigmas this may impede siring by conspecific pollen. As flower visitors forage within a spatial context, the distribution of plants may affect the type and magnitude of pollinator-mediated competition. In this study we examined two questions: 1) does the exotic plant, Carduus nutans (Asteraceae) interact with the native Monarda fistulosa (Lamiaceae) through flower visitors by changing visitation rate and/or through heterospecific pollen transfer, and does this affect seed set of the native plant? 2) Does spatial context affect how the native and exotic plants interact through flower visitors? We created plots containing potted M. fistulosa with and without the presence of potted C. nutans. In the presence of C. nutans, M. fistulosa stigmas had significantly fewer conspecific and more C. nutans pollen grains. Visitation rate and seed set tended to be lower in these invaded plots, however they were not significant. In a second experiment, we examined whether changes in visitation rate to M. fistulosa due to the presence of C. nutans was a function of M. fistulosa distance from C. nutans. We found that visitation rate did not decrease in the presence of C. nutans when M. fistulosa were adjacent to C. nutans or 15 meters from C. nutans. However, floral visitation rate to M. fistulosa decreased at 1 and 5 meters from C. nutans. Our results suggest interactions between plant species through flower visitors may depend on spatial scale. [ABSTRACT FROM AUTHOR]

We evaluated the efficacy of a mycophagous tydeid mite, Ortholydeus lambi, in controlling grape powdery mildew on mature vines of nine different grape cultivars and one unnamed hybrid grown in an experimental vineyard over a 3-year period. O. lambi became well established on all vines where they were released. However, some cultivars supported higher densities than others, depending on, among other factors, the presence and abundance of leaf trichomes in vein axils (domatia). The establishment of O. Lambi substantially reduced powdery mildew on foliage and fruit, although the magnitude of disease suppression was greater on some grape genotypes than others, depending on mite density and innate susceptibility to grape powdery mildew. Treatments where O. lambi was used alone were as effective as fungicide. Significantly better disease control was found in treatments with both mites and fungicides. The mass of pruning material and leaf photosynthetic rates were significantly greater for vines with O. lambi, fungicide, or a combination of mites and fungicide compared with untreated vines. The combination of mites and fungicide resulted in significantly greater yield than mites or fungicide alone. Our results illustrate the potential of O. lambi for biological control of grape powdery mildew but also high-light limitations related to differences among grape genotypes in innate susceptibility to mildew and suitability for mites. [ABSTRACT FROM AUTHOR]

Investigates the influence of domatia on the abundance of a tydeid mite, Orthotydeus lambi, in riverbank grapes. Impact of domatia on the fungal pathogen grape powdery mildew; Benefit derived by plants from acarodomatia.

Spurgia capitigena is a gall midge that has been released as a biological control agent of leafy spurge ( Euphorbia esula), a noxious rangeland weed in North America. We isolated 15 microsatellite loci from S. capitigena with from two to 27 alleles at each locus. These markers will allow us to examine the structure and levels of neutral genetic variation in native and introduced populations. [ABSTRACT FROM AUTHOR]

Abstract: What drives the evolution of increased growth and fecundity in plants introduced to a novel range is not well understood. We investigate between‐range differences in performance for Verbascum thapsus, a weedy invader known to grow larger in its introduced than native range. Specifically, we question whether adaptation to herbivory or climate best explains increased performance of introduced populations. We grew 14 native and 22 introduced populations of V. thapsus in two common garden locations: near Prague, Czech Republic (native range) and in Colorado, USA (introduced range). By removing herbivores from half of the plants within each garden we tested the prediction of the evolution of increased competitive ability (EICA) hypothesis: increased performance is driven by an evolutionary shift of resources away from defence against herbivory towards growth and reproduction. We then investigated whether genetically based clines in performance are expressed along climate gradients within both the native and introduced ranges. On average, seeds produce larger rosettes when collected from the introduced vs. native range. While this evolution of increased growth in introduced populations in part matches the prediction of EICA, climate, not herbivory, best explains this between‐range difference. Specifically, seeds collected from the native range produce smaller rosettes as the climate of origin becomes cooler and drier, while there is no cline in performance in rosettes grown from seed collected from the introduced range, which are large regardless of climate of origin. Thus, a climate‐based cline within the native range best explains lower average performance of native compared to introduced populations. Synthesis. The breakdown in a potentially adaptive cline emphasizes the need to more closely investigate the evolutionary processes that shape geographic structuring (or its absence) within the introduced range. In addition, EICA is not universally applicable to all invasion scenarios, and our findings underscore the importance of testing the underlying assumptions alongside the predictions of this hypothesis. [ABSTRACT FROM AUTHOR]

Dalmatian and yellow toadflax, Linaria dalmatica and L. vulgaris, are exotic weeds in North America, and their classical biological control has been improved by the establishment of seed-feeding (Rhinusa antirrhini) and stem-mining (Mecinus janthinus and Mecinus janthiniformis) weevils. Here, we evaluated the complex of hymenopteran parasitoids attacking these weevils in Colorado. Ten species were identified of the genera Neocatolaccus, Eurytoma, Pteromalus, Brasema, Telenomus and Bracon. Neocatolaccus tylodermae was the most abundant parasitoid of M. janthinus, M. janthiniformis and R. antirrhini. This is the first report of N. tylodermae attacking the weevil genera Mecinus and Rhinusa feeding on the genus Linaria. [ABSTRACT FROM AUTHOR]

A majority of the plant species that are introduced into new ranges either do not become established, or become naturalized yet do not attain high densities and are thus considered ecologically and economically unproblematic. The factors that limit these relatively "benign" species are not well studied. The biotic resistance hypothesis predicts that herbivores, pathogens and competition reduce growth and reproduction of individual plants and so suppress population growth of non-native species. We explored the effect of insect herbivory and surrounding vegetation on growth and fitness of the non-native biennial plant Verbascum thapsus (common mullein) in Colorado, USA. Mullein is widespread in its introduced North American range, yet is infrequently considered a management concern because populations are often ephemeral and restricted to disturbed sites. To evaluate the impact of insect herbivores on mullein performance, we reduced herbivory using an insecticide treatment and compared sprayed plants to those exposed to ambient levels of herbivory. Reducing herbivory increased survival from rosette to reproduction by 7%, from 70-77%. Of plants that survived, reducing herbivory increased plant area in the first year and plant height, the length of the reproductive spike, and seed set during the second year. Reducing herbivory also had a marked effect on plant fitness, increasing seed set by 50%, from about 48,000 seeds per plant under ambient herbivory to about 98,000 per plant under reduced herbivory. Our findings also highlight that the relationship between herbivory and performance is complex. Among plants exposed to ambient herbivory, we observed a positive relationship between damage and performance, suggesting that, as predicted by the plant vigor hypothesis, insect herbivores choose the largest plants for feeding when their choice is not restricted by insecticide treatment. In contrast to the strong effects of experimentally reduced herbivory, we found that cover of other plants surrounding our focal plants explained relatively little variation in performance outcomes. Overall, we found that herbivore-induced impacts on individual plant performance and seed set are substantial, and thus may help prevent this naturalized species from becoming dominant in undisturbed recipient communities. [ABSTRACT FROM AUTHOR]

Abstract: We used random sequences to determine which alignment methods are most susceptible to aligning sequences so as to create artifactual resolution and branch support in phylogenetic trees derived from those alignments. We compared four alignment methods (progressive pairwise alignment, simultaneous multiple alignment of sequence fragments, local pairwise alignment, and direct optimization) to determine which methods are most susceptible to creating false positives in phylogenetic trees. Implied alignments created using direct optimization provided more artifactual support than progressive pairwise alignment methods, which in turn generally provided more artifactual support than simultaneous and local alignment methods. Artifactual support derived from base pairs was generally reinforced by the incorporation of gap characters for progressive pairwise alignment, local pairwise alignment, and implied alignments. The amount of artifactual resolution and support was generally greater for simulated nucleotide sequences than for simulated amino acid sequences. In the context of direct optimization, the differences between static and dynamic approaches to calculating support were extreme, ranging from maximal to nearly minimal support. When applied to highly divergent sequences, it is important that dynamic, rather than static, characters be used whenever calculating branch support using direct optimization. In contrast to the tree-based approaches to alignment, simultaneous alignment of sequences using the similarity criterion generally does not create alignments that are biased in favor of any particular tree topology. [ABSTRACT FROM AUTHOR]

Abstract: We used simulations to compare the performance of 10 approaches that have been used for treating unambiguously aligned gaps in phylogenetic analyses. We examined how these approaches perform under the ideal conditions of correct alignments, as well as how robust they are to errors caused by use of inferred alignments. Our results indicate that 5th-state coding dramatically outperformed all other coding methods, which in turn all outperformed treating gaps as missing data or excluding gapped positions. Simple indel coding (SIC) and modified complex indel coding (MCIC) performed about the same, and generally outperformed the other indel-coding methods. The high performance of 5th-state coding was largely found to be a weighting artifact. We suggest that MCIC-coded gap characters be scored for all unambiguously aligned gaps in parsimony-based molecular phylogenetic analyses. When the number of terminals sampled precludes the use of MCIC, SIC may be used as an effective substitute. [Copyright &y& Elsevier]

Abstract: The distribution of phytophagous insects is influenced by their preference for and performance on their host plants. Biological control agents of invasive plants that prefer and perform better on their target hosts are more likely to be both effective and safe.Brachypterolus pulicarius is an herbivore used in North America to combat two invasive plants, yellow toadflax and Dalmatian toadflax (Linaria vulgaris and Linaria dalmatica). Adult beetles prefer yellow toadflax over Dalmatian toadflax, and when beetles are redistributed onto Dalmatian toadflax, populations do not consistently establish. This leads to the hypothesis that beetle larvae will perform best on yellow toadflax. A reciprocal transfer experiment was conducted to test this hypothesis. Development rate, pupal mass and percent survival were measured to assess larval performance. Development time was influenced by an interaction between the source host and the test host, a pattern suggesting that it is important to consider both the collection host and redistribution host when releasing this beetle for the control of toadflax. Pupal mass of larvae reared on yellow toadflax was, on average, 13% greater than that of larvae reared on Dalmatian toadflax, supporting the hypothesis. Survival rate was not significantly influenced by source host, test host, or their interaction, suggesting that survival rates will be similar no matter the combination of collection host and redistribution host. These results, along with the preference that adult beetles show for yellow toadflax, do not support the redistribution of B. pulicarius onto Dalmatian toadflax in North America. [Copyright &y& Elsevier]

Brachypterolus pulicarius (L.) (Coleoptera: Kateridae) is an inadvertently introduced biological control agent that can reduce seed set in two North American invasive species, yellow ( Linaria vulgaris P. Mill.) (Scrophulariaceae) and Dalmatian toadflax ( Linaria genistifolia (L.) P. Mill. ssp. dalmatica). The beetles are more common on yellow toadflax than on Dalmatian toadflax. To understand their distribution on the two host plants, we investigated whether they prefer one host to the other and whether individuals aggregate toward conspecifics. In field and laboratory experiments where beetles were presented with a choice of both toadflax species, B. pulicarius sampled from both host plants preferred yellow toadflax. However, in the laboratory experiment, beetles collected from Dalmatian toadflax showed a weaker preference for yellow toadflax than beetles collected from yellow toadflax. In the field experiment, all beetle populations sampled showed similar preferences. When given a choice between yellow toadflax plants with and without trapped adult B. pulicarius, beetles preferred plants with conspecifics, suggesting aggregation toward beetle pheromones or host-plant volatiles induced by beetle activity. These results do not support the current practice of redistributing North American B. pulicarius onto Dalmatian toadflax because of their preference for yellow toadflax. [ABSTRACT FROM AUTHOR]

• Manipulating plant defense hormones increases the impact of fungal pathogens. • Jasmonic acid application increased the impact of CT-Rust on Cirsium arvense. • This effect was seen for belowground but not aboveground biomass. Cirsium arvense, or Canada thistle, is one of the most detrimental weeds for agricultural production. Native to south-eastern Europe, the species is now found in Many parts of Asia, North America and Australasia. In North America and New Zealand the species is considered invasive, displacing native vegetation and reducing the quality of forage in rangelands and pastures. The autoecious fungus, Puccinia punctiformis , or CT-rust, shows potential as a control agent but rarely reaches epidemic proportions in natural populations. Manipulating plant defense hormones could alter host susceptibility and allow CT-rust to have more widespread impact. To determine if applying hormones increases the infection by the fungal pathogen, Canada thistle plants were inoculated and sprayed with jasmonic acid (JA) and salicylic acid (SA). Results show that jasmonic acid application interacted with inoculation, increasing infection rates, both incidence and severity, and impact of CT-rust. We found that JA increased infection rates by nearly 20%. Infection consistently reduced root biomass and this reduction was 45% greater with the addition of JA compared to untreated control. Addition of JA at the time of inoculation could make it a more effective control agent for Canada thistle. [ABSTRACT FROM AUTHOR]

Dispersal is a key ecological process that is strongly influenced by both phenotype and environment. Here, we show that juvenile environment influences dispersal not only by shaping individual phenotypes, but also by changing the phenotypes of neighbouring conspecifics, which influence how individuals disperse. We used a model system (Tribolium castaneum, red flour beetles) to test how the past environment of dispersing individuals and their neighbours influences how they disperse in their current environment. We found that individuals dispersed especially far when exposed to a poor environment as adults if their phenotype, or even one‐third of their neighbours' phenotypes, were shaped by a poor environment as juveniles. Juvenile environment therefore shapes dispersal both directly, by influencing phenotype, as well as indirectly, by influencing the external social environment. Thus, the juvenile environment of even a minority of individuals in a group can influence the dispersal of the entire group. [ABSTRACT FROM AUTHOR]

Teaching information literacy requires a constant and evolving paradigm shift in today's fast-changing technology era. Add to this the intricacy of agricultural science education, and it becomes clear that instructors face challenges teaching the necessary research skills to prepare the next generation of scientists. Two faculty members in Colorado State University's College of Agricultural Sciences identified a need to redesign a core agricultural science course after observing their students struggle with research and writing. These professors improved their course through a redesign program that connected them with librarians. This collaboration led to the creation of a scaffold to help students build information literacy skills through a first-year agricultural science course. In this paper the authors discuss this collaboration, including four key factors to the program's success: a) a faculty-librarian partnership through a learning and teaching institute; b) early exposure to information literacy skills in a first-year agricultural science course; c) the integration of a research guide in a Learning Management System (LMS), and a step-by-step library and information literacy instruction session with a library assignment; and d) a teach-the-teacher model using graduate students from the respective discipline. The authors also analyze student evaluation outcomes and reflect on future improvements. [ABSTRACT FROM AUTHOR]

Evolution has contributed to the successful invasion of exotic plant species in their introduced ranges, but how evolution affects particular control strategies is still under evaluation. For instance, classical biological control, a common strategy involving the utilization of highly specific natural enemies to control exotic pests, may be negatively affected by host hybridization because of shifts in plant traits, such as root allocation or chemical constituents. We investigated introgression between two parent species of the invasive shrub tamarisk (Tamarix spp.) in the western United States, and how differences in plant traits affect interactions with a biological control agent. Introgression varied strongly with latitude of origin and was highly correlated with plant performance. Increased levels of T. ramosissima introgression resulted in both higher investment in roots and tolerance to defoliation and less resistance to insect attack. Because tamarisk hybridization occurs predictably on the western U.S. landscape, managers may be able to exploit this information to maximize control efforts. Genetic differentiation in plant traits in this system underpins the importance of plant hybridization and may explain why some biological control releases are more successful than others. [ABSTRACT FROM AUTHOR]

Abstract: Many researchers have hypothesized that reduced genetic diversity in introduced populations of biological control agents can compromise the agent’s ability to establish and then adapt to novel environments. Strategies such as collecting from a wide geographic area or maintaining large colony sizes through the quarantine process have been used to minimize the loss of genetic diversity. Few studies have examined how the process of collection, quarantine, and establishment could affect patterns of genetic diversity in biological control agents. In this paper, we examine patterns in neutral genetic diversity in Spurgia capitigena, a gall midge introduced as a biological control agent of leafy spurge (Euphorbia esula) from its original collection site in Italy, a newly discovered population of the midge from southern France, and in two established populations in North America. By comparing the existing populations with historical samples collected shortly after the original introductions in 1991, we found that there is evidence of a mild bottleneck in both of the introduced populations. Further, we also examined the population structure in European populations of the fly collected from leafy spurge and a closely related species, cypress spurge (Euphorbia cyparissias) and found evidence for local restrictions in gene flow between populations on the two plants, but no evidence to support the current taxonomy of the genus with two distinct fly species. [Copyright &y& Elsevier]

Summary • Certain plant species hyperaccumulate selenium (Se) up to 0.6% of their dry weight. It is not known whether Se hyperaccumulation offers the plants any advantage. In this study the hypothesis was tested that Se can protect plants from invertebrate herbivory or fungal infection. • Indian mustard (Brassica juncea ) plants grown with or without Se were subjected to herbivory by caterpillars (Pieris rapae ) and snails (Mesodon ferrissi) , or to fungal infection by a root/stem pathogen (Fusarium sp.) and a leaf pathogen (Alternaria brassicicola ). • When given a choice between leaves with or without Se (0.1% Se of leaf d. wt), the caterpillars strongly preferred leaves without Se (P < 0.01), while the snails preferred leaves containing Se (P < 0.015). When consumed, the Se leaves were lethal to the caterpillars. The snails showed no toxicity symptoms, even though their tissue Se concentrations were comparable with the caterpillars. Se-containing plants were less susceptible to infection by both fungi. • In conclusion, Se was shown to protect Indian mustard plants from fungal infection and from herbivory by caterpillars, but not by snails. [ABSTRACT FROM AUTHOR]