The Essential Oil Compositions of Ambrosia acanthicarpa Hook., Artemisia ludoviciana Nutt., and Gutierrezia sarothrae (Pursh) Britton & Rusby (Asteraceae) from the Owyhee Mountains of Idaho.

As part of our interest in the volatile phytoconstituents of aromatic plants of the Great Basin, we have obtained essential oils of Ambrosia acanthicarpa (three samples), Artemisia ludoviciana (12 samples), and Gutierrezia sarothrae (six samples) from the Owyhee Mountains of southwestern Idaho. Gas chromatographic analyses (GC-MS, GC-FID, and chiral GC-MS) were carried out on each essential oil sample. The essential oils of A. acanthicarpa were dominated by monoterpene hydrocarbons, including α-pinene (36.7-45.1%), myrcene (21.6-25.5%), and ß-phellandrene (4.9-7.0%). Monoterpene hydrocarbons also dominated the essential oils of G. sarothrae, with ß-pinene (0.5-18.4%), α-phellandrene (2.2-11.8%), limonene (1.4-25.4%), and (Z)-ß-ocimene (18.8-39.4%) as major components. The essential oils of A. ludoviciana showed wide variation in composition, but the relatively abundant compounds were camphor (0.1-61.9%, average 14.1%), 1,8-cineole (0.1-50.8%, average 11.1%), (E)-nerolidol (0.0-41.0%, average 6.8%), and artemisia ketone (0.0-46.1%, average 5.1%). This is the first report on the essential oil composition of A. acanthicarpa and the first report on the enantiomeric distribution in an Ambrosia species. The essential oil compositions of A. ludoviciana and G. sarothrae showed wide variation in composition in this study and compared with previous studies, likely due to subspecies variation.

First record of non-native Xylosandrus compactus and Anisandrus maiche (Coleoptera: Curculionidae, Scolytinae) in Slovenia.

The introduction of non-native organisms into new areas may pose major threats to natural ecosystems. Therefore, continuous and careful national surveys for the interception of invasive non-native species are necessary. During the national survey of quarantine species in 2023, two new non-native ambrosia beetles, Anisandrus maiche (Kurentzov) and Xylosandrus compactus (Eichhoff), were recorded in Slovenia. Anisandrus maiche was recorded in three locations in the eastern part of Slovenia, with a total of 386 individuals. Three individuals of Xylosandrus compactus were collected in one location near the port of Koper. We discuss the possible pathways of introduction and dispersal.

Taxonomic changes for Neotropical pinhole borer ambrosia beetles (Coleoptera: Curculionidae: Platypodinae).

Stephen L. Wood re-defined Platypus such that its members are native to realms outside of the Americas and transferred most Neotropical species out of that genus. I have come across 44 species that still remain, though, and these are treated here. In total, I report 49 new generic assignments, 30 of which are transfers out of Platypus. I propose 22 new synonymies, eight of which are Platypus species that are synonymized with previously transferred species. Six Neotropical species are left in Platypus, for reasons detailed in the text. These taxonomic acts affect the compositions of eight of the 11 Neotropical genera of core Platypodinae. The following species are transferred from Platypus Herbst, 1793: Cenocephalus dubiosus (Schedl, 1933) comb. nov., Cenocephalus neotruncatus (Schedl, 1972) comb. nov.; Costaroplatus barbosai (Schedl, 1972) comb. nov., Costaroplatus devius (Schedl, 1976) comb. nov., Costaroplatus mixtus (Schedl, 1976) comb. nov., Costaroplatus roppai (Schedl, 1978) comb. nov.; Epiplatypus bicaudatulus (Schedl, 1935) comb. nov., Epiplatypus carduus (Schedl, 1936) comb. nov., Epiplatypus complanus (Schedl, 1967) comb. nov., Epiplatypus grandiporus (Schedl, 1961) comb. nov., Epiplatypus insculptus (Schedl, 1967) comb. nov., Epiplatypus macroporus (Chapuis, 1865) comb. nov., Epiplatypus perforans (Schedl, 1961) comb. nov., Epiplatypus propinquus (Schedl, 1959) comb. nov., Epiplatypus quadrispinatus (Chapuis, 1865) comb. nov., Epiplatypus sallei (Chapuis, 1865) comb. nov., Epiplatypus sequius (Schedl, 1935) comb. nov.; Euplatypus detectus (Schedl, 1976) comb. nov., Euplatypus erraticus (Schedl, 1972) comb. nov., Euplatypus longulus (Chapuis, 1865) comb. nov., Euplatypus perplexus Bright, 1972 comb. nov., Euplatypus rugosifrons (Schedl, 1933) comb. nov., Euplatypus vexans (Schedl, 1972) comb. nov.; Megaplatypus asperatus (Schedl, 1976) comb. nov., Megaplatypus carinifer (Schedl, 1970), Megaplatypus durus (Schedl, 1936) comb. nov., Megaplatypus eversus (Wood, 1971) comb. nov., Megaplatypus gagates (Schedl, 1976) comb. nov., Megaplatypus irrepertus (Schedl, 1936) comb. nov., Megaplatypus lineaticornis (Schedl, 1936) comb. nov., Megaplatypus paramonovi (Schedl, 1972) comb. nov., Megaplatypus schedli (Wood, 1966) comb. nov., Megaplatypus vafer (Schedl, 1972) comb. nov.; Teloplatypus caligatus (Schedl, 1972) comb. nov. Costaroplatus bidens (Schedl, 1970) comb. nov. and Costaroplatus darlingtoni (Reichardt, 1965) comb. nov. are transferred from Megaplatypus Wood, 1993. Costaroplatus vonfaberi (Reichardt, 1962) comb. nov. is transferred from Platyphysus Wood, 1993. Epiplatypus striatus (Chapuis, 1865) comb. nov., Megaplatypus contextus (Schedl, 1963) comb. nov., Megaplatypus decorus (Schedl, 1936) comb. nov. and Megaplatypus dignatus (Schedl, 1936) comb. nov. are removed from Euplatypus Wood, 1993. Epiplatypus ornatus (Schedl, 1936) comb. nov. is transferred from Teloplatypus Wood, 1993. Euplatypus jamaicensis Bright, 1972 comb. nov., Megaplatypus discolor (Blandford, 1896) comb. nov., Teloplatypus brasiliensis (Nunberg, 1959) comb. nov., Teloplatypus nudus (Schedl, 1936) comb. nov. and Teloplatypus pernudus (Schedl, 1936) comb. nov. are transferred from Epiplatypus Wood, 1993. Costaroplatus ornatus (Schedl, 1936) comb. nov., is transferred from Cenocephalus Chapuis, 1865. Megaplatypus acutidens (Blandford, 1895) comb. nov. and Megaplatypus despectus (Schedl, 1971) comb. nov. are transferred from Tesserocerus Saunders, 1837. New synonymies are proposed as follows: Cenocephalus rugicollis Schedl, 1952 (= Cenocephalus epistomalis Wood, 1966 syn. nov.); Tesserocerus forcipatus Schedl, 1972 (= Platypus aplanatus Schedl, 1976 syn. nov.); Tesserocerus retusus Gurin-Mneville, 1838 (= Tesserocerus guerini ssp. montanus Schedl, 1960 syn. nov.); Tesserocerus simulatus Schedl, 1936 (= Platypus bilobus Schedl, 1961 syn. nov.); Tesserocerus spinax Blandford, 1896 (= Tesserocephalus forficula Schedl, 1936 syn. nov.); Costaroplatus carinulatus (Chapuis, 1865) (= Platypus umbrosus Schedl, 1936 syn. nov.); Costaroplatus shenefelti Nunberg (1963) (= Platypus abditulus Wood, 1966 syn. nov.); Costaroplatus vonfaberi (Reichardt, 1962) (= Platypus convexus Schedl, 1972 syn. nov.); Epiplatypus sallei (Chapuis, 1865) (= Platypus quadricaudatulus Schedl, 1934 syn. nov. and = Platypus filaris Wood, 1971 syn. nov.); Euplatypus longulus (Chapuis, 1865) (= Platypus dimidiatus Chapuis, 1865 syn. nov. = Platypus mulsanti Chapuis, 1865 syn. nov. and = Platypus pseudolongulus Schedl, 1963 syn. nov. ); Megaplatypus acutidens (Blandford, 1895) (= Tesserocerus alternantes Schedl, 1977 syn. nov.); Megaplatypus durus (Schedl, 1936) (= Platypus arcuatus Schedl, 1976 syn. nov.); Megaplatypus fuscus (Chapuis, 1865) (= Platypus marginatus Chapuis, 1865 syn. nov., = Platypus granarius Schedl, 1952 syn. nov., and = Platypus obsitus Schedl, 1976 syn. nov.); Megaplatypus irrepertus (Schedl, 1936) (= Platypus sulcipennis Schedl, 1976 syn. nov.); Neotrachyostus abbreviatus (Chapuis, 1865) (= Platypus concavus Chapuis, 1865 syn. nov.); Teloplatypus enixus (Schedl, 1936) (= Platypus interponens Schedl, 1978 syn. nov.); Teloplatypus ratzeburgi (Chapuis, 1865) (= Platypus pallidipennis Blandford, 1896 syn. nov.). Platypus simpliciformis Wood, 1966 had been transferred by Wood (1993) to both Megaplatypus and Euplatypus by mistake; I propose keeping it in Megaplatypus. Six Neotropical species are left in the genus Platypus with the status incertae sedis: Platypus armatus Chapuis, 1865; Platypus dorsalis Schedl, 1972; Playpus quadrilobus Blandford, 1895; Platypus squamifer Schedl, 1963; Platypus subaequalispinosus Schedl, 1936; and Platypus trispinosus Chapuis, 1965. These taxonomic changes prepare the foundations for future revisionary work on the American Platypodinae.

New species, new synonymy, taxonomic notes and new records of bark and ambrosia beetles from the southwestern United States and northern Mexico (Coleoptera: Curculionidae: Platypodinae and Scolytinae).

Chaetophloeus flourensiae new species, is described from the Chihuahuan Desert from Arizona and western Texas and Hylocurus incognitus new species is described from Texas, Oklahoma and Louisiana. New synonymies include: Chramesus mimosae Blackman, 1938 (= Chramesus varius Wood, 1969); Hylocurus rudis (LeConte, 1876) (= Hylocurus binodatus Wood, 1974; Hypothenemus seriatus (Eichhoff, 1872) (= Stephanoderes multidentatus Hopkins, 1915, Stephanoderes nitidifrons Hopkins, 1915, Hypothenemus hopkinsi Browne, 1963); Hypothenemus pubescens Hopkins, 1915 (= Hypothenemus sparsus Hopkins, 1915, Hypothenenus similis Hopkins, 1915, Stephanoderes tridentatus Hopkins, 1915); Phloeotribus scabricollis Hopkins, 1916 (=Phloeotribus pseudoscabricollis Atkinson, 1989; Pseudothysanoes yuccae (Wood, 1956), (=Pseudothysanoes yuccavorus Wood, 1971); and Thysanoes texanus Blackman, 1943 (=Thysanoes mexicanus Wood, 1956). Hylocurus schwarzi Blackman, 1928, is redescribed including the first description of the female. New locality and host records that significantly extend the respective ranges are included for 30 species from the border region of the United States and Mexico.

A new widely distributed invasive alien species of Amasa ambrosia beetles (Coleoptera: Curculionidae: Scolytinae: Xyleborini).

Amasa parviseta Knek & Smith, new species is described from Australia, Brazil, Uruguay, France and Spain. The species is native to Australia and appears to have spread widely in association with introduced Eucalyptus species.

Radiation-Detoxified Form of Endotoxin Effectively Activates Th1 Responses and Attenuates Ragweed-Induced Th2-Type Airway Inflammation in Mice.

Urbanization with reduced microbial exposure is associated with an increased burden of asthma and atopic symptoms. Conversely, environmental exposure to endotoxins in childhood can protect against the development of allergies. Our study aimed to investigate whether the renaturation of the indoor environment with aerosolized radiation-detoxified lipopolysaccharide (RD-LPS) has a preventative effect against the development of ragweed-induced Th2-type airway inflammation. To explore this, cages of six-week-old BALB/c mice were treated daily with aerosolized native LPS (N-LPS) or RD-LPS. After a 10-week treatment period, mice were sensitized and challenged with ragweed pollen extract, and inflammatory cell infiltration into the airways was observed. As dendritic cells (DCs) play a crucial role in the polarization of T-cell responses, in our in vitro experiments, the effects of N-LPS and RD-LPS were compared on human monocyte-derived DCs (moDCs). Mice in RD-LPS-rich milieu developed significantly less allergic airway inflammation than mice in N-LPS-rich or common environments. The results of our in vitro experiments demonstrate that RD-LPS-exposed moDCs have a higher Th1-polarizing capacity than moDCs exposed to N-LPS. Consequently, we suppose that the aerosolized, non-toxic RD-LPS applied in early life for the renaturation of urban indoors may be suitable for the prevention of Th2-mediated allergies in childhood.

Artificial light at night reduces earthworm activity but increases growth of invasive ragweed.

BACKGROUND: Artificial light at night, also referred to as light pollution (LP), has been shown to affect many organisms. However, little is known about the extent to which ecological interactions between earthworms and plants are altered by LP. We investigated the effects of LP on anecic earthworms (Lumbricus terrestris) that come to the surface at night to forage and mate, and on the germination and growth of the invasive and allergenic ragweed (Ambrosia artemisiifolia). In a full factorial pot experiment in the greenhouse, we tested four factors and their interactions: LP (5 lux vs. 0 lux at night), earthworms (two individuals vs. none), plant species (seeding of ragweed only vs. mixed with Phacelia seeds) and sowing depth (seed placed at the surface vs. in 5 cm depth). Data were analysed using Generalized Linear (Mixed) Models and multifactorial ANOVAs with soil parameters as covariates. RESULTS: Light pollution reduced earthworm surface activity by 76% as measured by casting activity and toothpick index; 85% of mating earthworms were observed in the absence of LP. Light pollution in interaction with earthworms reduced ragweed germination by 33%. However, LP increased ragweed height growth by 104%. Earthworms reduced ragweed germination especially when seeds were placed on the soil surface, suggesting seed consumption by earthworms. CONCLUSIONS: Our data suggest that anecic earthworms are negatively affected by LP because reduced surface activity limits their ability to forage and mate. The extent to which earthworm-induced ecosystem services or community interactions are also affected by LP remains to be investigated. If the increased height growth of ragweed leads to increased pollen and seed production, it is likely that the competition of ragweed with field crops and the risks to human health will also increase under LP.

Chromosome-level genome of Ambrosia trifida provides insights into adaptation and the evolution of pollen allergens.

Ambrosia trifida (giant ragweed) is an invasive plant that can cause serious damage to natural ecosystems and severe respiratory allergies. However, the genomic basis of invasive adaptation and pollen allergens in Ambrosia species remain largely unknown. Here, we present a 1.66 Gb chromosome-scale reference genome for giant ragweed and identified multiple types of genome duplications, which are responsible for its rapid environmental adaptation and pollen development. The largest copies number and species-specific expansions of resistance-related gene families compared to Heliantheae alliance might contribute to resist stresses, pathogens and rapid adaptation. To extend the knowledge of evolutionary process of allergic pollen proteins, we predicted 26 and 168 potential pollen allergen candidates for giant ragweed and other Asteraceae plant species by combining machine learning and identity screening. Interestingly, we observed a specific tandemly repeated array for potential allergenic pectate lyases among Ambrosia species. Rapid evolutionary rates on putative pectate lyase allergens may imply a crucial role of nonsynonymous mutations on amino acid residues for plant biological function and allergenicity. Altogether, this study provides insight into the molecular ecological adaptation and putative pollen allergens prediction that will be helpful in promoting invasion genomic research and evolution of putative pollen allergy in giant ragweed.

In-gallery social behaviors of the ambrosia beetle, Xylosandrus germanus (Coleoptera: Curculionidae).

The east Asian ambrosia beetle Xylosandrus germanus (Blanford) was first detected in the United States in 1932. It now occurs across much of eastern North America and parts of the Pacific Northwest. It attacks a broad range of stressed, woody hosts including ornamental and orchard species. The foundress tunnels into the sapwood of hosts where it cultures a symbiotic fungus as food for its offspring. A few other ambrosia beetles have been shown to possess a facultatively eusocial structure among gallery members, but this has not been described for Xylosandrus spp. Using a novel artificial diet arena, we quantified the behaviors of X. germanus larvae and adults (foundress and mature offspring) over 10 wk inside their galleries. Foundresses were responsible for constructing the gallery. They also initially tended the fungal garden and brood but eventually spent most of their time blocking the gallery entrance. Larvae were mainly observed to feed, crawl, or be inactive within the gallery, regardless of the absence or presence of adult siblings. Adult female offspring were primarily inactive, likely due to dormancy. Adult male offspring actively crawled and attempted to mate with their sisters before eventually dispersing out of the gallery. Cooperative hygienic behaviors (removal of frass, cannibalism of dead nest mates, grooming siblings) were observed but a division of labor among offspring was not clear. Rather, foundress behaviors were mostly distinct from offspring behaviors, particularly as the gallery aged. Because no overlap in generations occurred, X. germanus displays a quasisocial structure.

Population genetic differentiation and phenotypic plasticity of Ambrosia artemisiifolia under different nitrogen levels.

Rapid adaptive evolution and phenotypic plasticity are two mechanisms that often underlie invasiveness of alien plant species, but whether they can co-occur within invasive plant populations under altered environmental conditions such as nitrogen (N) enrichment has seldom been explored. Latitudinal clines in plant trait responses to variation in environmental factors may provide evidence of local adaptation. Here, we inferred the relative contributions of phenotypic plasticity and local adaptation to the performance of the invasive plant Ambrosia artemisiifolia under different soil N levels, using a common garden approach. We grew A. artemisiifolia individuals raised from seeds that were sampled from six invasive populations along a wide latitudinal cline in China (23°42' N to 45°43' N) under three N (0, 5, and 10 g N m-2 ) levels in a common garden. Results show significant interpopulation genetic differentiation in plant height, number of branches, total biomass, and transpiration rate of the invader A. artemisiifolia across the N treatments. The populations also expressed genetic differentiation in basal diameter, growth rate, leaf area, seed width, root biomass, aboveground biomass, stomatal conductance, and intercellular CO2 concentration regardless of N treatments. Moreover, plants from different populations of the invader displayed plastic responses in time to first flower, hundred-grain weight, net photosynthetic rate, and relative biomass allocation to roots and shoots and seed length under different N treatments. Additionally, individuals of A. artemisiifolia from higher latitudes grew shorter and allocated less biomass to the roots regardless of N treatment, while latitudinal cline (or lack thereof) in other traits depended on the level of N in which the plants were grown. Overall, these results suggest that rapid adaptive evolution and phenotypic plasticity in the various traits that we quantified may jointly contribute to invasiveness of A. artemisiifolia under different levels of N availability. More broadly, the results support the idea that phenotypic plasticity and rapid adaptive evolution can jointly enable invasive plants to colonize a wide range of environmental conditions.

Mycobiomes of two distinct clades of ambrosia gall midges (Diptera: Cecidomyiidae) are species-specific in larvae but similar in nutritive mycelia.

IMPORTANCE: Ambrosia gall midges are endophagous insect herbivores whose larvae live enclosed within a single gall for their entire development period. They may exhibit phytomycetophagy, a remarkable feeding mode that involves the consumption of plant biomass and mycelia of their cultivated gall symbionts. Thus, AGMs are ideal model organisms for studying the role of microorganisms in the evolution of host specificity in insects. However, compared to other fungus-farming insects, insect-fungus mutualism in AGMs has been neglected. Our study is the first to use DNA metabarcoding to characterize the complete mycobiome of the entire system of the gall-forming insects as we profiled gall surfaces, nutritive mycelia, and larvae. Interestingly, larval mycobiomes were significantly different from their nutritive mycelia, although Botryosphaeria dothidea dominated the nutritive mycelia, regardless of the evolutionary separation of the tribes studied. Therefore, we confirmed a long-time hypothesized paradigm for the important evolutionary association of this fungus with AGMs.

Roads as conduits for alien plant introduction and dispersal: The amplifying role of road construction in Ambrosia trifida dispersal.

The initial disruption caused by road construction, combined with ongoing vehicular traffic and regular road maintenance, can repeatedly disturb the environment in ways that favor introduced alien plants. We hypothesized that several characteristics of road construction influence the introduction of alien plants and analyzed 444 Environmental Impact Assessment reports for insights into the relationship between the progression of construction and alien plant richness. Additionally, we believed that roads enhance seed dispersal post-construction, and tested this using Ambrosia trifida patches on completed roads. In 41 construction sites, a total of 137 alien plant species were identified, with 120 introduced after the onset of construction. Significant correlations were found between alien plant richness and road characteristics, with wider roads experiencing more newly introduced species, while longer roads had more total alien plants. As construction progressed, the richness of alien plants generally increased, with around 88 % of sites showing this trend. Changes in alien plant composition during construction revealed a transition from perennial to annual dominance. Post-construction, we found that vehicles played a role in Ambrosia trifida seed dispersal, with seeds predominantly dispersing in the direction of traffic. This study provides information on alien plant species that are commonly introduced and rapidly dispersed due to road construction. Overall, we showed that road construction and subsequent vehicle traffic are primary factors in the spread of alien plants, necessitating early management measures during construction to prevent their proliferation.

When a plant invader meets its old enemy abroad: what can be learnt from accidental introductions of biological control agents.

Accidental introductions of biological weed control (BWC) agents (i) offer opportunities to assess host use of agents with a potentially broader fundamental host-range than those approved for field release directly in target areas; (ii) urge national authorities to rapidly respond as they may threaten native species or crops, and by this (iii) help advancing post-release studies, a neglected aspect of BWC. Through detailed insights gained from studying the recent accidental introduction of the ragweed leaf beetle Ophraella communa into Europe, we derive suggestions for overcoming barriers to adoption of BWC by re-evaluating the predictive power of pre-release studies and, thus, the presently strict criteria for deciding upon their release that might exclude safe and efficient agents. By using the allergenic weed Ambrosia artemisiifolia and the accidentally introduced BWC agent O. communa as study system, we also hope to raise the awareness of authorities to consider biological control more prominently as a key approach for pest management in the 'One Health' concept, which aims to sustainably balance and optimize the health of people, animals, plants and ecosystems. © 2023 Society of Chemical Industry.

Sublingual immunotherapy tablets in monosensitized and polysensitized adults with allergic rhinoconjunctivitis.

Background: Most patients with allergic rhinitis/conjunctivitis (AR/C) are sensitized to more than one allergen. An ongoing question is the efficacy of single-allergen immunotherapy in patients who are polysensitized. Objective: To evaluate the efficacy and safety of grass, ragweed, tree, and house-dust mite (HDM) sublingual immunotherapy (SLIT) tablets in adults with AR/C who are mono- or polysensitized. Methods: Data from adults (ages ≥ 18 years) with AR/C who participated in phase III double-blind, placebo controlled field trials (four grass, two ragweed, two HDM, one tree) were included in the post hoc analyses. Efficacy was assessed by the total combined score (TCS) (sum of AR/C daily symptom and medication scores) during the entire pollen season for grass and tree trials, and peak pollen season for ragweed trials versus placebo. Efficacy for the HDM SLIT-tablet was assessed by the total combined rhinitis score (TCRS) (sum of rhinitis daily symptom and medication scores) during the last 8 weeks of treatment versus placebo. Results: For the grass SLIT-tablet, TCS improved by 20% (mean difference 1.33 [95% confidence interval {CI}, 0.44-2.22]) in the subjects who were monosensitized (n = 442) and 20% (mean difference 1.28 [95% CI, 0.90-1.67]) in the subjects who were polysensitized (n = 1857). For the ragweed SLIT-tablet, TCS improved by 19% (mean difference 1.72 [95% CI, -0.20 to 3.63]) in the subjects who were monosensitized (n = 115) and 27% (mean difference 2.27 [95% CI, 1.28-3.27]) in the subjects who were polysensitized (n = 528). For the tree SLIT-tablet, TCS improved by 54% (mean difference 4.65 [95% CI, 2.48-6.82]) in the subjects who were monosensitized (n = 138) and 34% (mean difference 2.51 [95% CI, 1.34-3.69]) in the subjects who were polysensitized (n = 437). For the HDM SLIT-tablet, TCRS improved by 20% (mean difference 1.24 [95% CI, 0.48-1.99]) in the subjects who were monosensitized (n = 468) and 17% (mean difference 0.85 [95% CI, 0.43-1.28]) in the subjects who were polysensitized (n = 1294). The overall safety profile was not qualitatively different between the subjects who were monosensitized and the subjects who were polysensitized. Conclusion: Grass, ragweed, tree, or HDM SLIT-tablet treatment is effective for the specific allergen in question in adults with AR/C and who are monosensitized or polysensitized. Targeting one relevant allergen with SLIT-tablets induces a clinical effect for that allergen in patients who were polysensitized.

Fusarium kuroshium is the primary fungal symbiont of an ambrosia beetle, Euwallacea fornicatus, and can kill mango tree in Japan.

This study identifies fungi associated with Euwallacea fornicatus and determines whether these fungal species play the role of primary symbiont. E. fornicatus adults that emerged from the branches of infested trees in Okinawa main island, Japan, were collected and used to isolate fungi. Fusarium kuroshium and Penicillium citrinum were the most dominant fungal associates of females and males, respectively. F. kuroshium was much more frequently isolated from the head, including mycangia (fungus-carrying organs), of females than any other body parts. We inoculated healthy mango saplings with F. kuroshium or F. decemcellulare, both of which were symbionts of E. fornicatus females infesting mango trees. F. kuroshium decreased leaf stomatal conductance and rate of xylem sap-conduction area and increased length and area of xylem discoloration of the saplings, thereby weakening and killing some. These results suggest that F. kuroshium, a mycangial fungus of E. fornicatus, inhibits water flow in mango trees. This study is the first to report that F. kuroshium causes wilt disease in mango trees and that it is a primary fungal symbiont of E. fornicatus.

Erwiniaceae bacteria play defensive and nutritional roles in two widespread ambrosia beetles.

Ambrosia beetles are fungal-growing insects excavating galleries deep inside the wood. Their success as invaders increased scientific interest towards them. However, most studies on their microbiota targeted their fungal associates whereas the role of bacterial associates is understudied. To explore the role of abundant microbial associates, we isolated bacteria from active galleries of two widespread ambrosia beetles, Xylosandrus crassiusculus and X. germanus. These isolates were classified within the Erwiniaceae family and through a phylogenetic analysis including isolates from other insects we showed that they clustered with isolates obtained from ambrosia and bark beetles, including Erwinia typographi. The whole genome analysis of the isolate from active galleries of X. crassiusculus suggested that this bacterium plays both a nutritional role, by providing essential amino acids and enzymes for the hydrolysis of plant biomass, and a defensive role, by producing antibiotics. This defensive role was also tested in vitro against fungi, including mutualists, common associates, and parasites. The bacteria inhibited the growth of some of the common associates and parasites but did not affect mutualists. Our study supported the hypothesis of a mutualist role of Erwiniaceae bacteria in ambrosia beetles and highlighed the importance of bacteria in maintaining the symbiosis of their host with nutritional fungi.

A high diversity of non-target site resistance mechanisms to acetolactate-synthase (ALS) inhibiting herbicides has evolved within and among field populations of common ragweed (Ambrosia artemisiifolia L.).

BACKGROUND: Non-target site resistance (NTSR) to herbicides is a polygenic trait that threatens the chemical control of agricultural weeds. NTSR involves differential regulation of plant secondary metabolism pathways, but its precise genetic determinisms remain fairly unclear. Full-transcriptome sequencing had previously been implemented to identify NTSR genes. However, this approach had generally been applied to a single weed population, limiting our insight into the diversity of NTSR mechanisms. Here, we sought to explore the diversity of NTSR mechanisms in common ragweed (Ambrosia artemisiifolia L.) by investigating six field populations from different French regions where NTSR to acetolactate-synthase-inhibiting herbicides had evolved. RESULTS: A de novo transcriptome assembly (51,242 contigs, 80.2% completeness) was generated as a reference to seek genes differentially expressed between sensitive and resistant plants from the six populations. Overall, 4,609 constitutively differentially expressed genes were identified, of which none were common to all populations, and only 197 were shared by several populations. Similarly, population-specific transcriptomic response was observed when investigating early herbicide response. Gene ontology enrichment analysis highlighted the involvement of stress response and regulatory pathways, before and after treatment. The expression of 121 candidate constitutive NTSR genes including CYP71, CYP72, CYP94, oxidoreductase, ABC transporters, gluco and glycosyltransferases was measured in 220 phenotyped plants. Differential expression was validated in at least one ragweed population for 28 candidate genes. We investigated whether expression patterns at some combinations of candidate genes could predict phenotype. Within populations, prediction accuracy decreased when applied to an additional, independent plant sampling. Overall, a wide variety of genes linked to NTSR was identified within and among ragweed populations, of which only a subset was captured in our experiments. CONCLUSION: Our results highlight the complexity and the diversity of NTSR mechanisms that can evolve in a weed species in response to herbicide selective pressure. They strongly point to a non-redundant, population-specific evolution of NTSR to ALS inhibitors in ragweed. It also alerts on the potential of common ragweed for rapid adaptation to drastic environmental or human-driven selective pressures.

China-US grain trade shapes the spatial genetic pattern of common ragweed in East China cities.

Common ragweed is an invasive alien species causing severe allergies in urban residents. Understanding its urban invasion pathways is crucial for effective control. However, knowledge is limited, with most studies focusing on agricultural and natural areas, and occurrence record-based studies exhibiting uncertainties. We address this gap through a study in East China cities, combining population genetics and occurrence records. Leaf samples from 37 urban common ragweed populations across 15 cities are collected. Genomic and chloroplast DNA extraction facilitate analysis of spatial genetic patterns and gene flows. Additionally, international grain trade data is examined to trace invasion sources. Results indicate spatial genetic patterns impacted by multiple introductions over time. We infer the modern grain trade between the United States and China as the primary invasion pathway. Also, cities act as transportation hubs and ports of grain importation might disperse common ragweed to urban areas. Invasive species control should account for cities as potential landing and spread hubs of common ragweed.

Integrating biogeographic approach into classical biological control: Assessing the climate matching and ecological niche overlap of two natural enemies against common ragweed in China.

Plant invasion is considered a high priority threat to biodiversity, ecosystems, the environment, and human health worldwide. Classical biological control (biocontrol) is a generally safer and more environmentally benign measure than chemical controls in managing invasive alien plants (IAPs). However, the impacts of climate change and the importance of climate matching in ensuring the efficiency of biocontrol candidates in controlling IAPs are likely to be underestimated. Here, based on the ensemble model and n-dimensional hypervolumes concepts, we estimated the overlapping areas between Ambrosia artemisiifolia and its two most effective natural enemies (Ophraella communa and Epiblema strenuana) under climate change in China. Moreover, we compared their ecological niches, further assessing the impact of climate change on the efficiency of two natural enemies in controlling A. artemisiifolia in China. We found that the potentially suitable areas of the two natural enemies and A. artemisiifolia were primarily influenced by temperature and human influence index variables. Under near-current climate, the overlapping area between O. communa and A. artemisiifolia was the largest, followed by E. strenuana and A. artemisiifolia, and both two natural enemies and A. artemisiifolia. The ecological niche between A. artemisiifolia and O. communa was most similar (0.64), followed by A. artemisiifolia and E. strenuana (0.55). The separate control (the niche separation areas of the two natural enemies against A. artemisiifolia) and joint-control (the niche overlap areas of the two natural enemies against A. artemisiifolia) efficiencies of the two natural enemies against A. artemisiifolia will both increase in future climates (the 2030s and 2050s) in northern and northeastern China. Our findings demonstrate a new approach to assess control efficiency and screen potential release areas of two natural enemies against A. artemisiifolia in China without the need for actual field release or experimentation. Moreover, our findings provide important clues for ensuring the classical biocontrol of IAPs worldwide.

A temporally and spatially explicit, data-driven estimation of airborne ragweed pollen concentrations across Europe.

Ongoing and future climate change driven expansion of aeroallergen-producing plant species comprise a major human health problem across Europe and elsewhere. There is an urgent need to produce accurate, temporally dynamic maps at the continental level, especially in the context of climate uncertainty. This study aimed to restore missing daily ragweed pollen data sets for Europe, to produce phenological maps of ragweed pollen, resulting in the most complete and detailed high-resolution ragweed pollen concentration maps to date. To achieve this, we have developed two statistical procedures, a Gaussian method (GM) and deep learning (DL) for restoring missing daily ragweed pollen data sets, based on the plant's reproductive and growth (phenological, pollen production and frost-related) characteristics. DL model performances were consistently better for estimating seasonal pollen integrals than those of the GM approach. These are the first published modelled maps using altitude correction and flowering phenology to recover missing pollen information. We created a web page (http://euragweedpollen.gmf.u-szeged.hu/), including daily ragweed pollen concentration data sets of the stations examined and their restored daily data, allowing one to upload newly measured or recovered daily data. Generation of these maps provides a means to track pollen impacts in the context of climatic shifts, identify geographical regions with high pollen exposure, determine areas of future vulnerability, apply spatially-explicit mitigation measures and prioritize management interventions.