Low Infestation Research Articles

Does the Lewis spider mite constitute a threat to agricultural crops in Europe? New data on occurrence, host plants and damage in the invaded areas in Portugal.

The Lewis spider mite (LSM), Eotetranychus lewisi, is an important pest of poinsettias (Euphorbia pulcherrima) and agricultural crops worldwide. In Europe it is a quarantine-regulated pest with established outdoor populations in Portugal. We investigated the pest status and host plants of the LSM in Madeira and the Algarve, collecting and inspecting plants and crops. The LSM was mainly found on naturalized poinsettias and castor-bean. Additionally, live mites were collected in very low numbers from plants of vine, cherimoya, mango, papaya, cherry plum, wild tobacco, and bladder vine, in direct contact or close to LSM-infested poinsettias, strongly suggesting these plants would not be breeding hosts. LSM abundance was low and no damage was observed. Mites were absent from strawberry, bramble and citrus, important hosts worldwide. Field surveys were complemented with a citizen-science experiment in outdoor conditions to test whether proximity to mite-infested poinsettias affected subsequent detections on poinsettia, strawberry, or grapevine. After two months of exposure to potentially dispersing LSM individuals and a further two months under controlled conditions to allow the mite to develop, LSM was detected on the three-recipient species but at low infestation rates, with a higher number of infested leaves and abundance on poinsettias, and absence of damages to crops. Overall, we conclude that the primary reservoirs for LSM populations in southwestern Europe are poinsettia and castor-bean plants, and our results suggest that the LSM is not causing damages to crops and may not be as harmful as expected, which can have implications to the current quarantine-regulation of this mite in Europe.

Prevalence and Associated Factors of Pediculosis capitis among Male Schoolchildren in Helmand Province, Afghanistan

Background: Pediculosis capitis (head lice infestation) is a significant public health concern, particularly among schoolchildren, because apart from physical symptoms, it also leads to their psychological distress, social stigma, and negative impacts on their school attendance and learning. Despite its global impact, there is a lack of research on this issue in Afghanistan. Methods: This descriptive cross-sectional study was performed among male schoolchildren from Jan to Dec 2023, in Helmand Province, Afghanistan. Data were collected through physical examination and a structured questionnaire, which gathered information on participants’ demographics, socioeconomic status, physical characteristics, environmental factors, and hygiene practices. Statistical analysis of the prevalence and associated risk factors was performed using SPSS. Results: Of the 306 participants, 26 (8.5%) had head lice infestation. Significant associations were observed between longer hair and higher infestation rates, as well as between older bathrooms and higher prevalence. Children from higher-income families had lower infestation rates, as did those with sweaty scalps. No significant associations were found with age, grade level, family size, parental education, physical traits, hair-washing products, or animal contact. Conclusion: This study offers critical baseline data on pediculosis capitis in Afghanistan and highlights the need for targeted public health interventions. It also establishes the basis for future research on the socio-economic and environmental factors contributing to lice infestations in the region.

Legume‐Colonising Aphids as Potential PNYDV‐Vectors: Reproduction and Infestation Dynamics in Two Different Field Bean Varieties

ABSTRACTFaba bean can be infected by Pea necrotic yellow dwarf virus (PNYDV), a novel pathogen throughout Europe, and transmitted persistently by several legume‐colonising aphid species. Recent field screenings in Austria and Germany of different faba bean varieties were encouraging as consistently the lowest viral symptom development in the variety ‘GL Sunrise’ was reported. However, our own greenhouse experiments revealed that ‘GL Sunrise’ was not resistant to PNYDV but showed a similar susceptibility such as other common varieties, for example, ‘Fuego’. Therefore, we suspected varietal host traits were affecting the reproductive potential of virus vector species with reduced virus transmission, probably explaining the empirical superior health status in the field. Under greenhouse conditions, vector‐specific intrinsic rates of increase (rm) for Acyrthosiphon pisum Harris Aphis fabae Scopoli and Megoura viciae Buckton were similar for both varieties, except for a particular A. pisum‐biotype derived from field pea, with a significantly reduced rm and fecundity in ‘GL Sunrise’. Furthermore, vector abundance assessments in multisite varietal showed A. pisum as the predominant species. In overall cross‐year and ‐site evaluation, early aphid census in ‘GL Sunrise’ at growth stage BBCH 61–65 indicated significantly lower primary A. pisum‐infestation pressure (factor 0,43 relative to ‘Fuego’). This lower infestation level in ‘GL Sunrise’ was kept until BBCH 77–79 but the difference had diminished down to the non‐significant factor of 0,74 A. pisum‐density relative to ‘Fuego’ in the late census, respectively. Based on our findings of (i) basic PNYDV susceptibility, (ii) similar reproductive vector performance of key aphid species, together with (iii) a significantly weaker initial A. pisum‐infestation levels in the field, we hypothesise ‘GL Sunrise’‐specific additional antixenosis/antibiotic traits, must influence host recognition and settling behaviour of alighting (viruliferous) migrants and/or apteres, which finally determine the superior PNYDV‐health status in ‘GL Sunrise’ at field conditions.

Life history traits, habitat characteristics, and phylogeny influence tick infestation probability in tropical wild birds

Interactions between wild birds and ticks exert significant selective forces, influencing the host's evolution and fitness. Tick infestation rates vary among bird species due to life history and morphology. Understanding tick infestation probability is crucial for conservation efforts, as birds play an important role in the tick life cycle and can transmit tick‐borne pathogens. In this context, it is essential to understand how life history traits or phylogenetic relationships determine tick infestation probability in the tropics. This study aims to identify wild bird life history traits and habitat characteristics associated with tick infestation probability in the Colombian tropical region. We hypothesized that larger body size, migratory behavior, foraging in lower vegetation stratum, seasonal aggregation, and inhabiting natural habitats increase tick infestation probability. We used a dataset with 3488 wild bird records from 322 species and 41 families, obtained from 61 Colombian localities (26 in the Orinoquia and 35 in the Andean regions). We used phylogenetic generalized linear mixed Bayesian models to assess tick infestation probability based on life history traits, body size, and geographic distribution. Of the birds analyzed, 3.2% were infested by ticks, mainly in immature stages (95%). Our results indicated a lower probability of tick infestation in agricultural habitats and higher elevations. Ground‐foraging species exhibited a lower infestation probability, contrary to previous reports. We found a significant phylogenetic relationship, indicating that related species have similar probabilities of tick infestation compared to more distantly related species. This study provides valuable insights into the bird–tick association, with implications for disease management and bird conservation.

In situ infestation of sea trout Salmo trutta with salmon louse Lepeophtheirus salmonis reveals parasite-induced behavioral modifications.

In areas with high densities of salmon farming, spillover of the ectoparasitic salmon louse Lepeophtheirus salmonis poses a major threat to wild anadromous salmonids. By combining experimentally salmon louse infestation (mean ± standard deviation = 0.25 ± 0.25 lice g-1 fish) with acoustic telemetry, we studied the behavior of wild first-time migrating sea trout Salmo trutta (n = 58, fork length = 138-204 mm) from late June to September in a marine area with naturally low infestation pressure. We observed that a similar proportion of sea trout from the control and exposed groups returned to fresh water both temporarily and permanently. However, sea trout from the control group spent nearly twice the amount of time in the fjord before first freshwater detection compared to exposed individuals (32 vs. 17 days), and statistical models indicated a dose-response of louse burden on the timing of freshwater return. This effect was combined with evidence of negative impacts of salmon louse burden on overall marine residency. Sea trout predominantly utilized waters within their natal fjord during the marine migration, with exposed fish spending significantly more time close to their home river than sea trout from the control group. In summary, the behavioral modifications caused by salmon lice could reduce individual marine growth, increase long-term mortality, and ultimately harm recruitment at the population level.

Classifying Serrated Tussock Cover from Aerial Imagery Using RGB Bands, RGB Indices, and Texture Features

Monitoring the location and severity of invasive plant infestations is critical to the management of their spread. Remote sensing can be an effective tool for mapping invasive plants due to its capture speed, continuous coverage, and low cost, compared to ground-based surveys. Serrated tussock (Nassella trichotoma) is a highly problematic invasive plant in Victoria, Australia, as it competes with the species in the communities that it invades. In this study, a workflow was developed and assessed for classifying the cover of serrated tussock in a mix of grazing pastures and grasslands. Using high-resolution RGB aerial imagery and vegetation field survey plots, random forest models were trained to classify the plots based on their fractional coverage of serrated tussock. Three random forest classifiers were trained by utilising spectral features (RGB bands and indices), texture features derived from the Grey-Level Co-occurrence Matrix, and a combination of all the features. The model trained on all the features achieved an overallaccuracy of 67% and a kappa score of 0.52 against a validation dataset. Plots with high and low infestation levels were classified more accurately than plots with moderate or no infestation. Notably, texture features proved more effective than spectral features for classification. The developed random forest model can be used for producing classified maps to depict the spatial distribution of serrated tussock infestation, thus supporting land managers in managing the infestation.

Development of Biofertiliser Based on Agricultural Waste for Sustainable Agriculture

Based on data from the Central Statistics Agency (BPS), the use of chemical fertilisers in Indonesia has increased by 50% in the last two decades, contributing to the decline of soil fertility and groundwater pollution (Rosadi, 2023). Research by the Indonesian Institute of Sciences (LIPI) found that the use of biofertilisers from agricultural waste can reduce the need for chemical fertilisers by up to 40%, while improving soil fertility in a sustainable manner. This research will focus on the development of agricultural waste-based biofertiliser formulations, with trials of their application in various crop types and land conditions in Indonesia. This research uses an experimental method with a quantitative approach, which aims to develop and test the effectiveness of agricultural waste-based biofertilisers. Table 1. The Bima variety (a1) has a larger number of plants than the Mentes variety (a2). Nutrient management also has a major impact on plant growth. Application of one dose of recommended NPK together with 100 kg/ha of pearl NPK (b3) and one dose of recommended NPK together with organic fertiliser and biofertiliser (b4) resulted in the highest plant growth at 8 weeks of age (Table 1). In the experiment, intensive pest control was carried out in the field. As a result, onion caterpillar (Spodoptera exigua hubn) populations per clump were low and fusarium wilt (Fusarium oxysporum hanz) infestation levels were generally low in both variety and nutrient management treatments. There was no evidence that varietal treatments or nutrient management had a significant impact. The application of agricultural waste-based biofertilisers not only improves crop yields, but also supports the sustainability of the agricultural ecosystem by minimising the use of synthetic chemicals and optimising the use of available resources.

The role of rehabilitating and restoration the green dam in managing the impact of invasive forest pests in Algeria

The rehabilitation of Algeria’s "Green Dam" project, a large-scale reforestation initiative, represents a key strategy for mitigating climate change, especially in semi-arid regions. This study, conducted between 2021 to 2024 in the semi-arid region of Djelfa (Algeria), evaluates the impact of defoliators in three different stands. Our findings reveal that infestation levels were significantly lower in mixed-species stands compared to monoculture stands, with monoculture plantations showing the highest infestation rates. Seasonal analysis revealed consistent stability in rehabilitated zones, with lower infestation indices throughout the year. The study highlights the role of species diversity in enhancing forest resilience to pest outbreaks, as mixed-species plantations naturally disrupt pest population dynamics and support healthier ecosystems. These results highlight the effectiveness of Green Dam’s rehabilitation in enhancing ecosystem health, increasing biodiversity, and reducing vulnerability to climate-induced disturbances, positioning it as a critical tool for ecological restoration and climate mitigation in northern Algeria. Furthermore, the project exemplifies a scientifically driven approach to combating desertification and climate change in semi-arid ecosystems. By integrating tritrophic analyses examining forest species, pest insects, and their antagonists—along with spatiotemporal monitoring, the study provides valuable insights into ecological interactions under changing climatic conditions. As expanding defoliators and xylophages pose increasing challenges, adaptive management strategies tailored to semi-arid regions are necessary. The rehabilitation of the Green Dam project emerges as a model for large-scale ecological restoration, combining reforestation efforts with scientific innovation to bolster ecosystem resilience, enhance sustainable land management, and address global issues such as biodiversity loss, desertification, and climate instability. Continued monitoring and adaptive management are essential to ensure the long-term success of reforested landscapes.

Incidence of Banana Pseudostem Weevil, Odoiporous longicollis Olivier (Coleoptera: Curculionidae) in Major Banana Growing Districts of Northern Karnataka, India

A roving survey during 2020-21 was undertaken in different banana growing districts of Northern Karnataka to study the prevalence and the magnitude of the infestation of the banana pseudostem weevil, O.longicollis and to know the varietal reaction and preference to the banana pseudostem weevil. Observations of the survey revealed that the districts - wise mean percent infestation varied from 3.73 in Belagavi to 15.35 in Vijayanagar district. The maximum mean percent infestation was recorded in Vijayanagar (15.35) and Kalaburgi (14.67) districts. This was followed by the lowest infestation in Belagavi (3.73) district. The mean per cent infestation varied from 2.50 in the Rajapuri variety to 22.53 in the Sugandhi cultivar across the varieties in different districts. In respect to varieties, Sugandhi banana recorded the maximum level of infestation (22.53) followed by Red banana (22.00), whereas, Elakki recorded 12.53 and 11.33 mean percent infestation in Vijayanagar and Uttara Kannada districts. Grand-Naine was cultivated in all the districts, while redbanana, Sugandhi and Sakkare bale were cultivated only in Kalaburgi and Vijayanagar districts. The mean damage grade index of banana pseudostem weevil across seven varieties in seven districts of North Karnataka revealed highest damage grade index in redbanana (0.98) at Kalaburgi followed by Sugandhi (0.75) in Vijayanagar district. There were statistically significant differences in percent infestation among seven varieties and also among seven districts. Hence, the study highlighted the infestation of banana pseudostem weevil varied in North Karnataka based on the variety, cultivation practices and geographical location.

Effect of Two Biofertilisers Based on Endophytic Fungi on Fall Armyworm Infestations in Maize Production in the Kara Region of Togo, West Africa

Aims: The aim of the study was to assess the efficacy of two biofertilisers based on endophytic fungi on infestation rates, foliar damage and maize yield losses caused by the armyworm, Spodoptera frugiperda, a worst maize pest. Study Design: Completely Randomized Design (CRD) with three types of treatments. Place and Duration of Study: Agronomic Experimentation Station of Tchitchao, Kara (Togo), between October 2019 and March 2020. Methodology: A complete randomized block design was used with three types of treatments: (i) maize seeds inoculated with Glomus sp. strain 142, (ii) maize seeds inoculated with Mycotri, (iii) maize seedlings fertilized with NPK and urea and finally (iv) a control consisting of seeds and/or seedlings of maize neither fertilized nor inoculated. Results: The results show that the plots treated with endophytic fungi recorded significantly lower infestation rates compared with the fertiliser treatments and the control. The highest infestation rates were 54% at 38 days after sowing (DAS) and 45% at 31 DAS for treatments with 5.35 x 105 spores/ha Glomus sp. and 0.38 kg/ha Mycotri, respectively, compared with 78% at 31 DAS and 62% at 38 DAS for fertiliser treatments and the control. The highest level of leaf damage, 2.92, was observed at 33 DAS on the plots fertilised with fertiliser, compared with scores of 2.53 and 2.38 for the plots mycorrhised with Glomus sp. and Mycotri, respectively. Yields were significantly higher in the fertilised plots (3.87 t/ha), followed by the mycorrhised plots (2.62-3.01 t/ha) and the control (1.73 t/ha). Conclusion: The endophytic fungi enabled the plants to tolerate fall armyworms attacks better than the controls, offering an alternative to chemical fertilisers and an effective option for managing soil fertility and controlling Spodoptera frugiperda.

Yield Yield loss and economic threshold estimates for pod borer (Helicoverpa armigera) in late maturing pigeonpea (Cajanus cajan)

Pod borer [Helicoverpa armigera (Hubner)] is a major biotic constraint to global pigeonpea production. The farmers largely apply synthetic insecticides to control this pest in pigeonpea. The study was conducted to quantify yield losses and estimate economic thresholds for H. armigera. The late maturing cultivar, IPA-203 was infested with different larval densities to determine the insect density-yield loss relationships. The yield response was variable and grain yield declined with increasing larval density from 1–5/plant. Yield loss of 4.56 kg/ha was evident for each unit increase in larval population. Economic threshold estimates indicated that the control measures for pod borer in IPA 203 cultivar should be initiated at an insect density of ≈1 larva/2 plants or at 3% pod damage to avoid the economic crop losses. The damage potential and economic threshold estimates are prerequisite for integrated pest management and reducing production costs (Alves et al. 2017). Present results indicated that relatively low infestations of H. armigera can cause significant yield reduction in pigeonpea hence intensive monitoring and timely control measures are necessary. Based on present economic threshold estimates, the farmers could decide the timing and kind of control measures to be initiated against pod borer in late pigeonpea cultivars to avert the economic losses.

Cover crop and herbicides can control purple nutsedge (Cyperus rotundus L.) and increase crop yields in conservation agriculture-based crop rotations

Cover crop and herbicides can control purple nutsedge (Cyperus rotundus L.) and increase crop yields in conservation agriculture-based crop rotations

XYLEM NAC DOMAIN 1 (EjXND1) relieves cold-induced lignification by negatively regulating the EjHB1-EjPRX12 module in loquat fruit

Lignin is a principal constituent of the secondary cell wall, which plays a role in both plant growth and defensing against stress, such as low temperature and pest infestation. Additionally, it also accumulates in fleshy fruits and negatively affects fruit quality. Red-fleshed loquat is temperature sensitive and exhibits cold-induced lignification. A number of technologies have been developed, for example, Low Temperature Conditioning (LTC) treatment, which has been applied in order to relieve the symptom of cold injury. The present study seeks to elucidate the regulatory mechanism underlying cold-induced lignification in loquat fruit. The target genes were isolated through the analysis of transcriptome. The gene function was analyzed by transient transgenic method in tobacco leaves and loquat fruit, respectively, as well as stable overexpression in liverwort. The regulatory mechanism study was achieved by in vitro protein-protein interaction assays, dual-luciferase assay, and EMSA. In the present study, the Xylem NAC Domain transcription factor EjXND1 was identified as a repressor of loquat fruit lignification. It was demonstrated that EjXND1 could interact with the characterized lignin activator EjHB1, resulting in a diminution of the activation of EjHB1 on EjPRX12 promoter. Furthermore, two highly methylated regions were identified in the promoter of EjXDN1. One of these regions exhibited a negative correlation between methylation level and EjXND1 expression. Additionally, it was shown that hypermethylation of this region weaken the binding affinity of EjXND1 activators to its promoter. The EjXND1 plays a role in modified Low Temperature Conditioning (mLTC) treatment that alleviates cold-induced lignification in red-fleshed loquat fruit by targeting the EjHB1-EjPRX12 module and EjXND1 is regulated by the dynamic of DNA methylation level in the promoter.

Wild salmon migration routes influence sea lice infestations: An agent-based model predicting farm-related infestations on juvenile salmon.

This study presents an Agent-Based Model (ABM) simulation to assess the impact of varying migration routes on sea lice (Caligus clemensi) infestation levels in juvenile wild sockeye salmon (Oncorhynchus nerka) in the Discovery Islands, British Columbia, Canada. This research highlights the importance of migratory routes in determining the extent of exposure to sea lice originating from nearby salmon farms. Three northward out-migration routes were modelled, each exposing the fish to different levels of infestation pressure based on proximity to salmon farms. The ABM incorporates spatially explicit migration patterns of juvenile sockeye salmon using a detailed raster map of the Discovery Islands. Key variables such as swimming speed, progression rate, and infestation levels were integrated into the model, offering a comprehensive analysis of migration and infestation dynamics. The study revealed that infestation rate is highly variable, depending on migration routes. Specifically, salmon traveling longer migration routes with lower infestation pressure may experience higher sea lice loads compared to those on shorter routes with higher infestation pressure. This underscores the role of low infestation pressures and the critical influence of swimming speed, which affects exposure time, and thus infestation rates. Additionally, the study conducted a sensitivity analysis to understand the influence of various parameters on infestation rates. This analysis highlighted the importance of swimming speed and progression rate, particularly in routes closer to the farms. The findings suggest that slower swimming speeds and meandering routes increase exposure to lice, thereby elevating infestation levels. The research contributes to understanding the dynamics of sea lice transmission and its relationship with salmon migration patterns. It underscores the necessity of considering migratory routes and farm proximity in managing and mitigating the impact of sea lice infestation on wild salmon populations. This study's insights are crucial for developing strategies to balance aquaculture practices with the conservation of wild salmon.

Biological control of tephritid fruit flies Bactrocera spp. in Himachal Pradesh, India

Over the years, chemical-based insecticides have been used to enhance crop yield in the agricultural industry. However, the hazards associated with these insecticides have highlighted the need for an alternative method that is economical, eco-friendly, and safe. In this investigation, the efficacy of various biological materials, such as Neem kavach, Beauveria bassiana (Balsamo), and clay, was evaluated against fruit flies under open field conditions. The results revealed that the highest infestation was recorded in the control (71.67 %), while the lowest infestation (25.67 %) was observed in the plot treated with B. bassiana (1.5 %). This was followed by Neem kavach-treated plot (4 %) with an infestation rate of 26.67 %, and the clay-treated plot (15 g/L) with an infestation rate of 38.67 %, after the third spray. The impact of these biological agents on cucumber yield was also evaluated. The highest yield, 9.36 kg/plot, was obtained from the B. bassiana-treated plot, followed by Neem kavach-treated plots with yields of 8.94 and 7.28 kg/plot, respectively. The lowest yield of 4.58 kg/plot was recovered in the untreated plots. These findings suggest that the application of these biological agents is highly effective, as they repel egg-laying (oviposition deterrence), thereby minimizing fruit infestation and maximizing yield profit.

Integrated Management of Rhizome Rot and Wilt Disease Complex of Ginger (Zingiber officinale) – A Review

This review article focuses on integrated management options for ginger diseases, especially rhizome rot and wilt. We compiled the results of several strategies, including chemical treatments, cultural practices, soil solarization, organic additions, and biological management for rhizome rot and wilt disease complex of ginger. Effective approaches includes (i) raise the temperature by soil solarization, (ii) additions of soil amendments like wood sawdust, oil cakes, neem cakes that prevent soil pathogen and simultaneously improve soil health, (iii) cultural techniques such as soil selection, crop rotation and intercropping, (iv) biological control using Trichoderma species is another useful method to lower infestation and increase ginger yield, and (v) use of chemical control measures such as Ridomil MZ, Metalaxyl, and Streptomycin. The above-listed aspects can be integrated to develop integrated management strategies that aid in developing a treatment strategy for management for rhizome rot and wilt disease complex of ginger.

Where does Aedes albopictus (Diptera: Culicidae) really breed in a Mediterranean residential area? Results from a field study in Valencia, Eastern Spain.

Since its introduction in Spain in 2004, Aedes albopictus has rapidly spread across the country. Its aggressive biting behaviour causes nuisance, limiting outdoor activities. Also, its role as a vector of several arboviruses implies a major public health risk, with several cases of autochthonous dengue having been reported nationwide over the past few years. Control strategies usually focus on interventions in breeding sites. As such, accurate knowledge of the main larval habitats becomes a major priority in infested areas. A detailed identification of breeding sites of Ae. albopictus was carried out in the outdoors of 60 residential properties during July-August 2022 in El Vedat de Torrent (Valencia, Eastern Spain), an area recently colonised by this species. A total of 1444 real and potential breeding sites were examined. The most abundant potential larval habitat were plant pot plates (6.48 units/house), although a low infestation level was found, both for larvae (2.06% positivity, x̄ = 30.5 larvae/container), and pupae (0.51%, x̄ = 2.5 pupae/container). A total of 7715 larvae and 205 pupae were found in a disused flooded water pool depuration system. Animal drinkers, buckets and irrigation water containers were found to be the most common positive containers. No statistical difference was observed among the different container materials. A general statistical increase of 1 larva per 11.7 ml of water in breeding sites was detected. Breeding sites of other species such as Culex pipiens (n = 2) and Culex modestus (n = 1) were also rarely found in this residential area. To our knowledge, this is the first aedic index study carried out in Europe, and it provides valuable information about the main domestic breeding habitats of Ae. albopictus, which can greatly improve control programmes.

Evaluation of techniques for controlling non-native sea lavenders in California coastal salt marshes

Two species of non-native sea lavender, Limonium ramosissimum (Poir.) Maire (Algerian sea lavender) and Limonium duriusculum (Girard) Fourr. (European sea lavender) are prolific invaders of California salt marshes. We examined the efficacy of three non-herbicide treatments [tarping, selective removal (hand pulling), and scraping], and one herbicide (Telar®) treatment, in eliminating L. ramosissimum and L. duriusulum, as well as treatment impacts to native vegetation within three southern California salt marshes. Our experiments demonstrated that the non-herbicide treatments initially suppressed cover of L. ramosissimum and L. duriusulum to near zero but varied over time in their suppression of L. ramosissimum and L. duriusulum, and their effects on native species. Depending on the tarping duration, tarping eradicates L. ramosissimum and L. duriusulum at least a year post treatment with little to no long-term negative impacts to native vegetation. Selective removal had minimal effect on native species but did not consistently suppress L. duriusulum over time. Scraping eradicates L. ramosissimum and L. duriusulum; however, its negative impacts on native species make it an undesirable treatment across large areas. The herbicide treatment was not as effective in suppressing L. ramosissimum, either initially or over time, and it negatively impacted native species. Our findings support the use of tarping as the primary management method to control or eradicate dense infestations of L. ramosissimum and L. duriusulum in salt marshes. We suggest that a combination of tarping and selective removal be used to control L. ramosissimum and L. duriusulum in areas of lower infestation.

Biodegradation effects of three Aspergillus species on iron-based oxides (Hematite − Goethite) in paint layer in oil paintings

Biodegradation effects of three Aspergillus species on iron-based oxides (Hematite − Goethite) in paint layer in oil paintings

Physiological effects of interacting native and invasive bivalves under thermal stress

Across many ecosystems in North America and Europe, native freshwater bivalves (Order Unionida) are threatened by fouling and competition for food by the invasive zebra mussel Dreissena polymorpha. In light of climate change, knowledge on the influence of water temperature on these competitive effects is important, yet poorly understood. This study examines the physiological impact of the interaction between D. polymorpha and the native European unionid Anodonta cygnea over a 28 day—period in response to water temperatures of 12, 19, and 25 °C by comparing their glycogen, glucose, lipid and protein concentrations. The laboratory experiment comprised three treatments: (1) fouling of A. cygnea by D. polymorpha, (2) both species present but not fouling; and (3) a control in which A. cygnea and D. polymorpha were placed separately. Increased water temperatures caused physiological stress in D. polymorpha as evident from reduced glycogen, glucose, lipid and protein concentrations. Dreissena polymorpha benefited from fouling of unionids, as individuals that fouled A. cygnea tended to have increased glycogen, glucose, lipid and protein concentrations. Competitive effects of D. polymorpha over the unionid bivalve species, however, were not intensified by elevated temperatures. Glochidia release, lower infestation intensity, and physiological stress of Dreissena at higher temperatures were likely confounding factors. The results of this study suggest that understanding the physiological consequences of species interactions at changing temperatures can be an important tool to assess future climate change impacts on freshwater bivalves and aquatic community structures.