Life Cycle Traits Research Articles

Present and future suitability of invasive and urban vectors through an environmentally driven mosquito reproduction number.

Temperature and water availability significantly influence mosquito population dynamics. We have developed a method, integrating experimental data with insights from mosquito and thermal biology, to calculate the basic reproduction number ([Formula: see text]) for urban mosquito species Aedes albopictus and Aedes aegypti. [Formula: see text] represents the number of female mosquitoes produced by one female during her lifespan, indicating suitability for growth. Environmental conditions, including temperature, rainfall and human density, influence [Formula: see text] by altering key mosquito life cycle traits. Validation using data from Spain and Europe confirms the approach's reliability. Our analysis suggests that temperature increases may not uniformly benefit Ae. albopictus proliferation but could boost Ae. aegypti expansion. We suggest using vector [Formula: see text] maps, leveraging climate and environmental data, to predict areas susceptible to invasive mosquito population growth. These maps aid resource allocation for intervention strategies, supporting effective vector surveillance and management efforts.

Two near-chromosomal-level genomes of globally-distributed Macroascomycete based on single-molecule fluorescence and Hi-C methods

Discinaceae holds significant importance within the Pezizales, representing a prominent group of macroascomycetes distributed globally. However, there is a dearth of genomic studies focusing on this family, resulting in gaps in our understanding of its evolution, development, and ecology. Here we utilized state-of-the-art genome assembly methodologies, incorporating third-generation single-molecule fluorescence and Hi-C-assisted methods, to elucidate the genomic landscapes of Gyromitra esculenta and Paragyromitra xinjiangensis. The genome sizes of two species were determined to be 47.10 Mb and 48.20 Mb, with 23 and 22 scaffolds, respectively. 10,438 and 11,469 coding proteins were identified, with functional annotations encompassing over 96.47% and 94.40%, respectively. Assessment of completeness using BUSCO revealed that 98.71% and 98.89% of the conserved proteins were identified. The application of comparative genomic technology has helped in identifying traits associated with of heterothallic life cycle traits and elucidating unique patterns of chromosomal evolution. Additionally, we identified potential saprotrophic nutritional modes and systematic phylogenetic relationships between the two species. Therefore, this study provides crucial genomic insights into the evolution, nutritional type, and ecological roles of species within the Pezizales.

Trait Composition and Assemblage Structure Analyses of Lacustrine Fishes: Synthesizing a Proposal for Better Fishing Practices

Fish provide ecosystem services and contribute to human well-being through fishing. In Chile, subsistence fishing provides food to local communities, whereas recreational fishing contributes to economic income via tourism. In the Lanalhue coastal lake basin, unregulated subsistence fishing and formal recreational fishing primarily target large fish species to ensure satisfactory catches and food provision. However, the development of unplanned fishing activities and lack of scientific knowledge can lead to socioecological conflicts and tension between users. To address this issue, this study focuses on improving fishing practices through the analysis of fish assemblages of the Lanalhue lake basin. The life cycle traits of each fish species were analyzed, as well as their abundance and biomass in each habitat. Twelve fish species were identified, and their distribution and abundance explain the differences in fish assemblage composition and structure among habitats. To promote better fishing practices, we propose four target species and specific management actions. These include defining fishing seasons, delineating fishing sites, and establishing fishing quotas. This approach, considering both community structure and functional aspects of fish assemblages, can serve as a valuable guide for developing sustainable fishing practices in the Lanalhue coastal lake basin.

The sediment of a river having ‘’good ecological status” turned out to be toxic to midge Chironomus riparius larvae: Implication for environmental monitoring?

Globally, monitoring of the surface waters is largely limited to the physico-chemical analysis of water in rivers and lakes. Sediment state in the aquatic systems including sediment chemical content or the structure and diversity of benthic communities or ecotoxicological studies with natural sediments remains largely overlooked by the monitoring programs. Hence we assessed the potential toxicity of three riverine sediments on the life-cycle traits (emergence and reproduction) of midge Chironomus riparius via an ecotoxicological testing method over two generations (according to OECD test 233 guidelines). In addition, the riverine sediments were spiked with polyamide (nylon) microplastic particles (1 g kg−1) to analyze an additive effect of microplastic on the sediment toxicity. As model river systems, three rivers (Karchaghbyur, Gavaraget, Argichi) in the Lake Sevan basin (Armenia) were selected. Results of ecotoxicity testing were compared with the indices of water quality (derived from the physico-chemical analysis) and the indices of the ecological status of the rivers (derived from the analysis of benthic communities). The results of testing demonstrated an unexpectedly low emergence of midges after the first generation exposed to the sediment of the river having ‘’good ecological status’’ - the Argichi. Sediments of the Karchaghbyur and Gavaraget rivers impeded the emergence and reproduction of midges after the second generation. An addition of polyamide particles to the sediments did not significantly affect the life-cycle traits of C. riparius indicating the primary effect of the sediments’ condition. The discrepancy of biotesting result with that of the other two methods (which indicated ‘’average water quality’’ and “good ecological status”) underlies the importance of designing more comprehensive monitoring programs for better assessment and protection of aquatic systems and resources.

Unveiling population-specific outcomes: Examining life cycle traits of different strains of Chironomus riparius exposed to microplastics and cadmium questions generality of ecotoxicological results.

Ecotoxicological tests used for risk assessment of toxicants and its mixtures rely both on classical life-cycle endpoints and bioindicator organisms usually derived from long-term laboratory cultures. While these cultures are thought to be comparable among laboratories and more sensitive than field organisms, it is not well investigated whether this assumption is met. Therefore, we aimed to investigate differential life-cycle endpoints response of two different strains of C. riparius, one originally from Spain and the other from Germany, kept under the same laboratory conditions for more than five years. To highlight any possible differences, the two populations were challenged with exposure to cadmium (Cd), polyvinyl chloride (PVC) microplastics and a co-exposure with both. Our results showed that significant differences between the strains became evident with the co-exposure of Cd and PVC MPs. The German strain showed attenuation of the deleterious Cd effects with microplastic co-exposure in survival and developmental time. Contrary to that, the Spanish strain showed no interaction between the substances. In conclusion, the toxicity-effects of contaminants may vary strongly among laboratory populations, which makes a universal risk assessment evaluation challenging.

Comparative analysis of metacyclogenesis and infection curves in different discrete typing units of Trypanosoma cruzi

Chagas disease (CD), caused by the complex life cycle parasite Trypanosoma cruzi, is a global health concern and impacts millions globally. T. cruzi’s genetic variability is categorized into discrete typing units (DTUs). Despite their widespread presence in the Americas, a comprehensive understanding of their impact on CD is lacking. This study aims to analyze life cycle traits across life cycle stages, unraveling DTU dynamics. Metacyclogenesis curves were generated, inducing nutritional stress in epimastigotes of five DTUs (TcI (MG), TcI (DA), TcII(Y), TcIII, TcIV, and TcVI), resulting in metacyclic trypomastigotes. Infection dynamics in Vero cells from various DTUs were evaluated, exploring factors like amastigotes per cell, cell-derived trypomastigotes, and infection percentage. Statistical analyses, including ANOVA tests, identified significant differences. Varying onset times for metacyclogenesis converged on the 7th day. TcI (MG) exhibited the highest metacyclogenesis potential. TcI (DA) stood out, infecting 80% of cells within 24 h. TcI demonstrated the highest potential in both metacyclogenesis and infection among the strains assessed. Intra-DTU diversity was evident among TcI strains, contributing to a comprehensive understanding of Trypanosoma cruzi dynamics and genetic diversity.

The interplay between climatic niche evolution, polyploidy and reproductive traits explains plant speciation in the Mediterranean Basin: a case study in Centaurium (Gentianaceae).

Speciation and diversification patterns in angiosperms are frequently shaped by niche evolution. Centaurium Hill is a Mediterranean genus with ca. 25 species, of which 60% are polyploids (tetra- and hexaploids), distributed mainly in the Mediterranean Basin and in areas with temperate and arid climates of Asia, Europe, North-Central Africa and North America. The evolutionary history of this genus has been studied using morphological, biogeographical and molecular approaches, but its climatic niche characterization and its relation with genome evolution (chromosome number and ploidy level) has not been addressed yet. Thus, this study aims to identify the role of the evolution of climatic niche, ploidy level, life cycle and floral traits in the diversification of Centaurium. Climatic niche characterization involved estimating present climate preferences using quantitative data and reconstructing ancestral niches to evaluate climatic niche shifts. The evolution of climatic niche towards selective optima determined by ploidy level (three ploidy levels) and different binary traits (polyploidy, floral size, floral display, herkogamy and life cycle) was addressed under the Ornstein-Uhlenbeck model. Chromosome number evolution was inferred using the ChromoSSE model, testing if changes are clado- or anagenetic. Chromosome number evolution and its link with cladogenesis, life cycle and floral traits was modeled on the phylogeny. The reconstruction of the ancestral niches shows that Centaurium originated in a mild climate and diversified to both humid and cold as well as to dry and warmer climates. Niche conservatism was estimated in the climatic niche of the ancestors, while the climatic niche of the current taxa experienced transitions from their ancestors' niche. Besides, the evolution of climatic niche towards multiple selective optima determined by the studied traits was supported, life cycle optima receiving the highest support. The reconstruction of chromosome number transitions shows that the rate of speciation process resulting from chromosomal changes (chromosomal cladogenesis) is similar to that of non-chromosomal cladogenesis. Additionally, dependent evolution of floral size, floral display and herkogamy with chromosome number variation was supported. In conclusion, polyploidization is a crucial process in the Mediterranean region that assisted speciation and diversification into new areas with different climates, entailing niche shifts and evolution of reproductive strategies.

Ducellierialesord. nov. and evidence for a novel clade of endobiotic pollen-infecting "lagenidiaceous" Peronosporomycetes.

The genus Ducellieria (Ducellieriaceae) contains three species (D. chodatii, D. tricuspidata, D. corcontica), and a single variety (D. chodatii var. armata) of obligate endobiotic pollen parasites. These organisms have been first assigned to the green alga genus Coelastrum, as they form very similar spherical structures, but the observation of heterokont zoospores has led to their reclassification to the phylum Oomycota. However, despite their widespread nature, these organisms are only known from their descriptive morphology, and life cycle traits of some species still remain incompletely known. Only the type species, D. chodatii, has been rediscovered several times, but the phylogeny of the genus remains unresolved, since none of its species has been studied for their molecular phylogeny. At present the genus is still included in some algal databases. To clarify the evolutionary affiliation of Ducellieria, efforts were undertaken to isolate D. chodatii from pollen grains, to infer its phylogenetic placement based on nrSSU sequences. By targeted isolation, the pollen endoparasitoid was rediscovered from three lakes in Germany (Mummelsee, Okertalsperre, Knappensee). Apart from the typical coelastrum-like spheroids, oomycetes sporulating directly from pollen grains in a lagenidium-like fashion were observed, and molecular sequences of both types of oomycetes were obtained. Phylogenetic reconstruction revealed that coelastrum-like and lagenidium-like forms are unrelated, with the former embedded within the deep branching early-diverging lineages, and the later stage forming a distinct clade in Peronosporales. Consequently, the life cycle of D. chodatii needs careful revision using single-spore isolates of the species, to infer if previous lifecycle reconstructions that involve various different thallus types are stages of a single species or potentially of several ones. Citation: Buaya AT, Thines M (2023). Ducellieriales ord. nov. and evidence for a novel clade of endobiotic pollen-infecting "lagenidiaceous" Peronosporomycetes. Fungal Systematics and Evolution 12: 247-254. doi: 10.3114/fuse.2023.12.12.

Dry storage alters intraspecific variation in phenotypic traits at early life stages: evidence from a dominant alpine meadow species

AbstractThe intraspecific variations of phenotypic traits in the early life stages, such as seed germination and seedling establishment, are important components affecting species adaptation and differentiation. As one of the most common ways in which seeds are maintained, dry storage usually affects these traits, by either increasing or decreasing variation among populations. However, little is known about how the interaction between dry storage and population variation of a species affects the performance and adaptability of early life-cycle traits. In this study, we conducted experiments with seeds from ten populations of Elymus nutans along an altitudinal gradient on the eastern Qinghai-Tibet Plateau. Fresh seeds and seeds stored dry for 6 months were used to quantify the temperature thresholds for germination, determine seedling emergence and survival in two common gardens and examine the correlation between these traits and environmental conditions of population provenance. Dry storage increased germination percentage, germination speed and seedling emergence, and decreased intraspecific variation in germination traits of seeds (reduced by 33.36, 52.05 and 20.45% for Tb, θT(50) and σθT, respectively). Dry storage had little effect on the intraspecific variation of seedling emergence and survival. In addition, the temperature threshold for germination cannot be used to predict seedling emergence and survival in either common garden, regardless of whether seeds were stored or not. These results indicated that it is feasible to use dry-stored seeds to evaluate and select suitable provenances in ecological restoration, and using dry-stored seeds in ecological restoration projects is expected to achieve better vegetation restoration results than fresh seeds. On the other hand, the status of seeds (fresh vs. dry stored) should be considered in an evaluation of the adaptive value of plant functional traits, especially in the early life stages, otherwise, inconsistent conclusions may be drawn.

Genomic Basis of Freshwater Adaptation in the Palaemonid Prawn GenusMacrobrachium: Convergent Evolution Following Multiple Independent Colonization Events.

Adaptation to different salinity environments can enhance morphological and genomic divergence between related aquatic taxa. Species of prawns in the genus Macrobrachium naturally inhabit different osmotic niches and possess distinctive lifecycle traits associated with salinity tolerance. This study was conducted to investigate the patterns of adaptive genomic divergence during freshwater colonization in 34 Macrobrachium species collected from four continents; Australia, Asia, North and South America. Genotyping-by-sequencing (GBS) technique identified 5018 loci containing 82,636 single nucleotide polymorphisms (SNPs) that were used to reconstruct a phylogenomic tree. An additional phylogeny was reconstructed based on 43 candidate genes, previously identified as being potentially associated with freshwater adaptation. Comparison of the two phylogenetic trees revealed contrasting topologies. The GBS tree indicated multiple independent continent-specific invasions into freshwater by Macrobrachium lineages following common marine ancestry, as species with abbreviated larval development (ALD), i.e., species having a full freshwater life history, appeared reciprocally monophyletic within each continent. In contrast, the candidate gene tree showed convergent evolution for all ALD species worldwide, forming a single, well-supported clade. This latter pattern is likely the result of common evolutionary pressures selecting key mutations favored in continental freshwater habitats Results suggest that following multiple independent invasions into continental freshwaters at different evolutionary timescales, Macrobrachium taxa experienced adaptive genomic divergence, and in particular, convergence in the same genomic regions with parallel shifts in specific conserved phenotypic traits, such as evolution of larger eggs with abbreviated larval developmental.

First report of Puccinia glechomatis, a rust fungus of creeping charlie, in Minnesota.

In 2020 and 2021, at four locations around the Twin Cities, Minnesota (Sep. 2021: 44.980, -93.319; Aug 2021: 44.989, -93.186; Sep 2020: 45.000, -93.138; Sep. 2020: 44.870, -92.779), a rust fungus was observed infecting creeping charlie (Glechoma hederacea), a weed of Eurasian origin (Hutchings and Price, 1999). Within stands, severity ranged from 1 to 30 % leaf loss. Telia were reddish-brown when young, starting small (0.1 to 0.5 mm), and growing into round but irregular sori measuring 1 to 5 mm, sometimes coalescing to form larger sori (Fig 1A). Sori are primarily abaxial, forming depressions on the adaxial surface, and sometimes occurring along stems and leaf petioles. Partial leaf necrosis occurs with high foliar infection and leaf dieback with high infection of petioles. Thin-walled, colorless leptosporic teliospores, or leptospores, (Fig 1B) were present in samples. Dark, thick-walled teliospores were not noted. Leaves bearing leptospores were soaked in water for four hours and suspended over young plants in a dew chamber at 20 °C for 16 hours. Plants were maintained in a greenhouse at 20-22 °C. After three weeks, nascent telia were observed on inoculated plants. The ITS region and a segment of EF1-α were selected for sequencing for the samples from the first two listed locations. For the ITS, the primers ITS1rustF10d (Barnes and Szabo, 2007) and ITSRu1 (Rioux et al., 2015) were used, and for EF1-α, a reaction was conducted following van der Merwe (2007). Amplicons were barcoded and sequenced on an Oxford Nanopore MinIon following manufacturer instructions (kits EXP-PBC001 and SQK-LSK109 with R9 flow cells). Reads (PRJNA802185) were filtered for quality (> Q16), sorted and separated by length, and aligned. A consensus sequence was generated for each amplicon with >50x coverage. BLAST searches of the EF1-α sequences OM489402 and OM489403 from the first two locations respectively showed 99.3 % (643/647) and 99.7 % (645/647) similarity with Puccinia glechomatis (EF560587). ITS sequences had not been reported for P. glechomatis, and there are no matches with >96 % homology in GenBank for the sequences OM470970 or OM470969, from the same samples. Morphological and life cycle traits are consistent with this identification. Creeping charlie is a common weed of turf, gardens, orchards, forests, and meadows. It is present in 46 of the lower 48 United States but is most common east of the Great Plains, in the Pacific Northwest, and in neighboring regions of southern Canada (Böllman and Scholler, 2004). P. glechomatis was recorded for the first time in 1992 in north-central Pennsylvania (Böllmann and Scholler, 2006). Examination of herbarium specimens and surveys established its distribution across the eastern U.S. and in a small area in the Pacific Northwest by the early 2000s, and in 2001 its presence was recorded in southern Wisconsin (Böllmann and Scholler, 2006). The basidiospores likely do not travel far, but the fungus may move long distances through plant matter and establish in new locations (Böllmann and Scholler, 2006). P. glechomatis is not known to affect native plants and may have a positive ecological effect, reducing the vigor of its undesirable host. To our knowledge, this is the first report of P. glechomatis in Minnesota. It is evidence of the continued westward spread of this rust in North America (Böllmann and Scholler, 2006). Sequenced samples were submitted to the Arthur Fungarium at Purdue University (PUR N24012 and PUR N24013, respectively).

Different behavioral strategies of two sympatric seahorses: habitat availability and increased density of Hippocampus guttulatus alter the behavior of Hippocampus hippocampus

In the light of future ocean warming scenarios and habitat fragmentation, coastal fishes must adjust their physiological and behavioral traits to face the combined effect of global warming and ecological interactions. Seahorses (Hippocampus spp.) are charismatic fishes with peculiar life cycle traits, which make them vulnerable to several anthropic pressures and natural disturbances. In this study, we investigated the behavior of two sympatric seahorse species, the long-snouted Hippocampus guttulatus (Cuvier, 1829) and the short-snouted Hippocampus hippocampus (Linnaeus, 1758). Specifically, we carried out two manipulative experiments to assess (i) the effect of temperature and habitat availability on both H. hippocampus and H. guttulatus behavior and (ii) the effect of temperature and an increased density of H. guttulatus (by 3×) on the activity level of congeneric species H. hippocampus. Our results showed that +3°C warming did not affect seahorse behavior in both experiments, suggesting greater behavioral tolerance to thermal variation. However, a significant reduction of the active behavior of H. hippocampus was observed when the artificial habitat was introduced in the tank, while H. guttulatus maintained its activity. Furthermore, a significant decrease of the H. hippocampus activity was observed with an increased relative dominance of H. guttulatus. Our results suggest that both increased density of H. guttulatus and habitat availability, but not ocean warming, will affect the behavior of H. hippocampus. Therefore, different interspecific behavioral strategies may occur, thus affecting the distribution of the two species among shallow habitats when they occur in sympatry.

Time-variant destination lifecycle model and the coactive development process

ABSTRACT The central tenet of the tourism-area lifecycle (TALC) rests on the idea of change. This paper utilized latent-growth curve modelling (LGCM) to synthesize a time-variant lifecycle model that quantifies changes in TALC-based hotel development. We accommodated the model with cross-lagged analysis to draw causal inferences. Based on data collected from 197 economies from UNWTO, findings reveal that the onset and growth rate of hotel development are associated with growth trajectories of tourist arrivals and overnight stays, which are subsequently associated with the growth trajectory of travel expenditure. A reciprocal influence between hotel development and tourist arrivals is also evident, suggesting a coevolutionary process underpinning TALC. This study adds to the nascent concept of multiplicity tourism-area lifecycles to denote an intricate web of linkages among different lifecycle traits of a destination. It improvises the concept of coactive development and paves the way for destination coevolution to articulate evolutionary interactions between tourists and tourism operators through reciprocal changes.

Life-cycle traits in the demosponge Hymeniacidon perlevis in a land-based fish farm.

The demosponge Hymeniacidon perlevis is characterized by wide geographic distribution and great adaptability to numerous and highly variable climatic and hydrological conditions. Indeed, the species can colonize many different environments, including several unusual ones, such as concrete drainage conduits of a marine land-based fish farm plant. This research aimed to enhance existing knowledge on the reproductive cycle and growth performance of H. perlevis while also evaluating the impact of a controlled supply of trophic resources, wastewater flow and constant water temperature on these biological traits. Specimens included in this one-year study inhabited drainage conduits of a land-based fish farm. The approach included measurements of sponge biomass and occurrence and abundance of reproductive elements across different seasons and environmental parameters, such as fish biomass, trophic resources, and wastewater flow. Sponge growth and reproductive elements, including oocytes, spermatic cysts, and embryos, were measured monthly in sponges positioned in the drainage conduit, thus with different trophic resources but with constant water temperature. Finally, we used generalized additive models to describe variables that contribute the most to the growth of sponges. Growth performance showed marked variations during the study period. The highest increase in sponge volume was observed from August/September to January/March. The volume of sponges was principally determined by the reduction of reared fish biomass and the increase of pellet amount and wastewater flow. Sponge specimens exhibited an active state during the entire study, as proven by the occurrence of recruits. However, sexual elements were only sporadically observed, thus not permitting the recognition of a true sexual cycle. The results of the present study confirmed that H. perlevis exhibits high flexibility and adaptability to the differential, and somewhat extreme, environmental conditions. Indeed, this species can live, grow and reproduce in the drainage conduits of the fish farm, where the species face constant darkness, water temperature and continuous nutritional supply. In such conditions, H. perlevis display an active state during the entire year, while avoiding stages of decline and long dormancy usually observed in wild populations. It seems plausible that stable environmental conditions induce an almost continuous sexual phase, probably under the control of endogenous factors. No asexual elements were detected, although it was impossible to exclude the contribution of asexual reproduction in the origin of the newly settled sponges, which were repeatedly detected throughout the study. The growth performance seemed linked to the fish farm conditions, thus providing useful indications on the best maintenance conditions for H. perlevis in land-based integrated multitrophic systems, where the species could be used for wastewater treatment.

Enhanced detoxification via Cyt-P450 governs cross-tolerance to ALS-inhibiting herbicides in weed species of Centaurea

Centaurea is a genus of winter weeds with a similar life cycle and competitive traits, which occurs in small-grains production fields in the central-southern of the Iberian Peninsula. However, most of herbicides recommended for weed management in wheat show poor control of Centaurea species. This study summarizes the biology, herbicide tolerance to acetolactate synthase (ALS) inhibitors, and recommended chemical alternatives for the control of Centaurea species. Four species (C. cyanus L., C. diluta Aiton, C. melitensis L. and C. pullata L. subsp. baetica Talavera), taxonomically characterized, were found as the main important broadleaf weeds in small-grains production fields of the Iberian Peninsula. These species showed innate tolerance to tribenuron-methyl (TM), showing LD50 values (mortality of 50% of a population) higher than the field dose of TM (20 g ai ha−1). The order of tolerance was C. diluta (LD50 = 702 g ha−1) ≫ C. pullata (LD50 = 180 g ha−1) ≫ C. cyanus (LD50 = 65 g ha−1) > C. melitensis (LD50 = 32 g ha−1). Centaurea cyanus and C. melitensis presented higher foliar retention (150–180 μL herbicide solution), absorption (14–28%) and subsequent translocation (7–12%) of TM with respect to the other two species. Centaurea spp. plants were able to metabolize 14C-TM into non-toxic forms (hydroxylated OH-metsulfuron-methyl and conjugated-metsulfuron-methyl), with cytochrome P450 (Cyt-P450) monooxygenases being responsible for herbicide detoxification. Centaurea cyanus and C. mellitensis metabolized up to 25% of TM, while C. diluta and C. pullata metabolized more than 50% of the herbicide. Centaurea species showed 80–100% survival when treated with of florasulam, imazamox and/or metsulfuron-methyl, i.e., these weeds present cross-tolerance to ALS inhibitors. In contrast, auxin mimics herbicides (2,4-D, clopyralid, dicamba, fluroxypir and MCPA) efficiently controlled the four Centaurea species. In addition, the mixture of ALS-inhibitors and auxin mimics also proved to be an interesting alternative for the control of Centaurea. These results show that plants of the genus Centaurea found in the winter cereal fields of the Iberian Peninsula have an innate tolerance to TM and cross-resistance to other ALS-inhibiting herbicides, governed by reduced absorption and translocation, but mainly by the metabolization of the herbicide via Cyt-P450.

Effects of Polyurethane Small-Sized Microplastics in the Chironomid, Chironomus riparius: Responses at Organismal and Sub-Organismal Levels

Freshwater provides valuable services and functions to humankind. However, macroinvertebrates that underpin the delivery of many of those ecosystem services and functions are under an additional threat caused by microplastic pollution. Chironomids are one of the most abundant groups of macroinvertebrates in these environments and the most sensitive to microplastics. This investigation addressed the effects of polyurethane (PU-MPs; 7.0-9.0 µm) on the chironomid Chironomus riparius at the organism and sub-organism levels. For this purpose, two assays were carried out: (i) addressing the effects of PU-MPs on C. riparius partial life cycle traits (larval size and emergence parameters) in a 28 d assay considering concentrations up to 750 mg/Kg, and (ii) larvae behaviour (locomotion) as well as the biochemical responses (oxidative damage, aerobic energy production, and energy reserves) in a 10 d assay considering an environmentally relevant concentration with no observed effects on C. riparius previous life history traits (no observed effect concentration; NOEC = (375 mg/kg). Exposure to PU-MPs did not affect C. riparius larval length nor cumulative and time to emergence. Conversely, when exposed to an environmentally relevant concentration for 10 days, contaminated larvae were revealed to be lighter (but not smaller nor less nutritionally affected in terms of energy reserves) and more active when foraging, which was reflected in the activation of their aerobic metabolism when assessing the electron transport chain as a proxy. Notwithstanding, PU-MPs did not originate observable energy costs, either on protein, lipid, or sugar contents on contaminated larvae, which may justify the absence of effects on larval growth and emergence. Therefore, the increased production of energy used for the locomotion and functioning of larvae was at the expense of the fraction of energy that should have been allocated for the weight of the individuals. A long-term exposure involving a multigenerational assessment would bring intel on the potential (cumulative) sub-lethal effects of PU-MPs on C. riparius fitness.

Hybridization rate and fitness of hybrids produced between the tetraploid Camelina rumelica and hexaploid Camelina sativa

Pre-release risk assessment of genetically modified (GM) Camelina sativa (L.) Crantz requires a careful evaluation of the reproductive compatibility with its closely-related Camelina species. Camelina rumelica Velen. is a naturalized weed occurring in C. sativa production region in the northwestern China. In this study, a large number of reciprocal crosses was conducted between the tetraploid C. rumelica and hexaploid C. sativa. The F1 hybrids were produced by the tetraploid C. rumelica (♀) × hexaploid C. sativa (♂) at the rate of one hybrid for 217 ovules pollinated, and one hybrid for 220 ovules pollinated in the reciprocal direction. All F1 hybrids required vernalization treatment to induce timely flowering and showed the significant lower pollen viability (< 2%) compared to the parental lines. Despite that the F1 failed to backcross with the parental lines, selfed seeds (F2) were obtained from F1 hybrids plants. The F2 hybrids showed some degree of restored pollen viability (about 20%) and successfully produced seeds by both backcrossing and self-pollination. A similar pattern was observed in the field, with F1 hybrids showing self-compatibility and reduced seed production potential. It is worthwhile to mention that all F1 and F2 plants grew well both in the greenhouse and field conditions, but with the significant lower seed production ability. A portion of selfed F2 seeds from naturally shattering persisted in the soil seedbank during summer period and subsequently germinated in late fall. By contrast, other F2 seeds may have been dormant in the soil seedbank and germinated the following spring. These altered life-cycle related traits in hybrids generates the novel ecological concerns on the persistence and population dynamics of transient hybrids in the seedbank. In summary, this study provided the evidence that the tetraploid C. rumelica and hexaploid C. sativa, which have the sympatric distributions and overlapped flowering periods, gene flow between them probably could occur. Although the rate was relatively low (about 0.5%), the introgression of life-cycle related traits into C. sativa population could alter its key life-cycle traits and raise the concerns on the soil seedbank persistence and invasiveness of transient hybrid in C. sativa production region in the northwestern China.

Assessment of the spatiotemporal risk of avian influenza between waterfowl and poultry farms during the annual cycle: A spatial prediction study focused on seasonal distribution changes in resident waterfowl in South Korea.

Previous studies and efforts to prevent and manage avian influenza (AI) outbreaks have mainly focused on the wintering season. However, outbreaks of AI have been reported in the summer, including the breeding season of waterfowl. Additionally, the spatial distribution of waterfowl can easily change during the annual cycle due to their life-cycle traits and the presence of both migrants and residents in the population. Thus, we assessed the spatiotemporal variation in AI exposure risk in poultry due to spatial distribution changes in three duck species included in both major residents and wintering migrants in South Korea, the mandarin, mallard and spot-billed duck, during wintering (October-March), breeding (April-June) and whole annual seasons. To estimate seasonal ecological niche variations among the three duck species, we applied pairwise ecological niche analysis using the Pianka index. Subsequently, seasonal distribution models were projected by overlaying the monthly ranges estimated by the maximum entropy model. Finally, we overlaid each seasonal distribution range onto a poultry distribution map of South Korea. We found that the mandarin had less niche overlap with the mallard and spot-billed duck during the wintering season than during the breeding season, whereas the mallard had less niche overlap with the mandarin and spot-billed duck during the breeding season than during the wintering season. Breeding and annual distribution ranges of the mandarin and spot-billed duck, but not the mallard, were similar or even wider than their wintering ranges. Similarly, the mandarin and spot-billed duck showed more extensive overlap proportions between poultry and their distributional ranges during both the breeding and annual seasons than during the wintering season. These results suggest that potential AI exposure in poultry can occur more widely in the summer than in winter, depending on sympatry with the host duck species. Future studies considering the population density and variable pathogenicity of AI are required.

Biology and Rearing of an Emerging Sugar Beet Pest: The Planthopper Pentastiridius leporinus.

Simple SummarySyndrome des Basses Richesses (SBR) is a bacterial yellowing disease of sugar beet (Beta vulgaris) that reduces the sugar content of the root tissue significantly. There is currently neither a cure for the disease nor effective control measures for the main insect vector, the Cixiid planthopper Pentastiridius leporinus. SBR is therefore spreading in Germany and has caused substantial yield losses in recent years. The development of effective control measures requires a better understanding of P. leporinus biology, including its life cycle and feeding behavior. We therefore established methods for the continuous mass rearing of P. leporinus. In host plant choice experiments, we found that the nymphs are polyphagous when offered sugar beet, winter wheat or maize. Life cycle data indicated that adult planthoppers emerge 170 days after hatching, having passed through five larval instar stages. We developed a state-of-the-art qRT-PCR protocol using TaqMan probes to study the prevalence of two bona fide SBR pathogens: Candidatus Arsenophonus phytopathogenicus (Gammaproteobacteria) and Candidatus Phytoplasma solani (stolbur phytoplasma). These were identified during field studies in newly-infected regions of Rhineland-Palatinate and south Hesse, Germany, where we also observed insect mobility patterns in two consecutive years, including the abundance of adults at four locations and soil-depth monitoring of nymphs. We documented the spread of P. leporinus northward and eastward in Germany, accompanied by an increase in the number of SBR-carrying planthoppers. Interestingly, P. leporinus does not appear to hibernate during winter. Stolbur phytoplasma has a significant impact on SBR pathology in sugar beet.The rapid spread of the bacterial yellowing disease Syndrome des Basses Richesses (SBR) has a major impact on sugar beet (Beta vulgaris) cultivation in Germany, resulting in significant yield losses. SBR-causing bacteria are transmitted by insects, mainly the Cixiid planthopper Pentastiridius leporinus. However, little is known about the biology of this emerging vector, including its life cycle, oviposition, developmental stages, diapauses, and feeding behavior. Continuous mass rearing is required for the comprehensive analysis of this insect. Here we describe the development of mass rearing techniques for P. leporinus, allowing us to investigate life cycle and ecological traits, such as host plant choice, in order to design agronomic measures that can interrupt the life cycle of nymphs in the soil. We also conducted field studies in recently-infected regions of Rhineland-Palatinate and south Hesse, Germany, to study insect mobility patterns and abundance at four locations during two consecutive years. The soil-depth monitoring of nymphs revealed the movement of the instars through different soil layers. Finally, we determined the prevalence of SBR-causing bacteria by designing TaqMan probes specific for two bona fide SBR pathogens: Candidatus Arsenophonus phytopathogenicus (Gammaproteobacteria) and Candidatus Phytoplasma solani (stolbur phytoplasma). Our data suggest that P. leporinus is spreading northward and eastward in Germany, additionally, the abundance of SBR-carrying planthoppers is increasing. Interestingly, P. leporinus does not appear to hibernate during winter, and is polyphagous as a nymph. Stolbur phytoplasma has a significant impact on SBR pathology in sugar beet.

Swimming Activity as an Indicator of Seasonal Diapause in the Copepod Calanus finmarchicus

Copepods dominate zooplankton biomass of the upper ocean, especially in the highly seasonal boreal and polar regions, for which specific life-cycle traits such as the accumulation of lipid reserves, migration into deep water and diapause are key adaptations. Understanding such traits is central to determining the energetic consequences of high latitude range shifts related to climate change and ultimately, biogeochemical models of carbon flow. Using the calanoid copepod Calanus finmarchicus, we explore a new indicator of diapause, swimming activity, and assess its relationship with respiration. Stage CV copepods were sampled in late summer from shallow (epipelagic) and deep (mesopelagic) water at both slope and basin locations within the Fram Strait at a time when the animals had entered diapause. Using high-throughput quantitative behaviour screening on ex-situ swimming activity, we found that irrespective of sampling station copepods from the mesopelagic show highly reduced activity (88.5 ± 3.4% reduction) when compared to those from the epipelagic with a clearly defined threshold between epi- and mesopelagic animals (~5 beam breaks 30 min-1). Mesopelagic individuals were also larger (12.4 ± 8.8%) and had more lipid reserves (19.3 ± 2.2%) than epipelagic individuals. On average, copepods from the basin station exhibited respiration rates similar to overwintering rates observed elsewhere (1.23 ± 0.76 µg C d-1), while respiration rates of copepods from the shelf station were more consistent with active metabolism (2.46 ± 1.02 µg C d-1). Nevertheless, active and diapausing rates were observed in individuals from both stations at both epi- and mesopelagic depths. We suggest that rapid screening of activity may provide an early indicator of diapause before it becomes fully apparent and consistent in other physiological indicators. Ultimately, swimming activity may provide a useful tool to assess the putative endogenous and exogenous factors involved in diapause onset, provide a handle on the energetics of diapause, and input to biogeochemical carbon models on C. finmarchicus.