Significant Reduction In Population Research Articles

Evaluation of Hypochlorite Effectiveness as a Disinfectant Against Aerobic Bacteria

Hypochlorite compounds, including calcium hypochlorite (Ca(OCl)₂) and sodium hypochlorite (NaOCl), are widely recognized for their broad-spectrum antimicrobial properties. This study aimed to evaluate the effectiveness of hypochlorite as a disinfectant against aerobic bacteria, providing insights into its application in infection control and water treatment. The study employed the aerobic bacteria number test, also known as the total plate count method, to enumerate bacterial colonies before and after exposure to varying concentrations of hypochlorite solution. Water samples were collected from different sources, including an emergency room floor, a pharmaceutical installation, and a hospital inpatient room. Serial dilutions of the water samples were prepared and plated on nutrient agar, followed by incubation and colony counting to determine the bacterial load. The percentage reduction in bacterial numbers was calculated for each hypochlorite dose. The results demonstrated a significant reduction in bacterial populations following hypochlorite treatment. A dose of 30 mL/5 L (6 μL/mL) reduced the average number of bacteria by 83.29%, A dose of 60 mL/5 L (12 μL/mL) reduced the average number of bacteria by 98.60%, A dose of 120 mL/5 L (24 μL/mL) reduced the average number of bacteria by 99.84%, A dose of 240 mL/5L (48 μL/mL) reduced the average number of bacteria by 99.98%, A dose of 480 mL/5L (96 μL/mL) reduced the average number of bacteria by 100%. The extent of bacterial reduction was directly proportional to the hypochlorite dose, indicating a clear dose-response relationship. In conclusion, this study confirms the efficacy of hypochlorite as a disinfectant against aerobic bacteria. A hypochlorite dose of 480mL/5L (96 μL/mL) effectively achieved complete bacterial elimination under the tested conditions. The results support its use in various applications, including disinfection of surfaces and water purification.

The Survivability of Bacterial Contaminants on a Retracted Stainless-Steel Needle Within a Novel Vascular Access Device

Highlights Abstract Background: Over-the-needle (OTN) peripheral intravenous catheters (PIVCs) are crucial in modern medicine. However, the OTN design allows for direct catheter-to-skin contact during insertion, leaving the sterile catheter at risk for bacterial contamination from the skin. A novel through-the-needle (TTN) PIVC design aims to minimize this risk by shielding the sterile catheter during insertion with the introducer needle. This needle then permanently retracts into the device housing and remains with the patient. In this study, we evaluate the survivability of bacterial contaminants on the retracted needle to address concerns about potential infection risks associated with this design. Methods: Fifteen TTN PIVC devices were inoculated with Staphylococcus aureus (101 to 102 CFU) on the outer surface of the needle. After needle retraction, devices were stored for 0, 24, 72, and 120 hours. At each time point, devices were processed, and bacterial survival was quantified using standard microbiological techniques. Results: The initial bacterial load (105.1 ± 51.4 CFU per device) decreased significantly over time. By 72 hours, bacterial count had reduced to 1.4 ± 2.4 CFU per device, representing a 98.7% reduction (P < 0.05). No significant change was observed between 72 and 120 hours. The most substantial decline occurred within the first 72 hours, with the difference between 0 hours and both 72 and 120 hours being statistically significant (P = 0.016 for both). Conclusions: The significant reduction in bacterial population on the retracted needle over time suggests a low risk of bacterial propagation within the TTN PIVC device. These findings indicate that the TTN design effectively addresses catheter contamination concerns during insertion without introducing additional infection risks due to needle retention.

Pasture and diurnal temperature are key predictors of regional Plains Spotted Skunk (Spilogale interrupta) distribution.

The Plains Spotted Skunk (Spilogale interrupta) is a small carnivore native to central North America that has experienced significant population reductions, and there is a lack of information about the species that could inform conservation. Our study aimed to address knowledge gaps about the distribution and habitat associations of the species in South Dakota using species distribution modeling. We used species location data collected from state natural resource managers, trappers, and members of online social media groups dedicated to hunting and wildlife conservation; environmental predictors; and 6 predictive modeling algorithms (i.e., artificial neural networks, artificial classification tree analysis, generalized boosting models, maximum entropy, multivariate adaptive regression splines, and random forests) to develop climate and landcover ensemble distribution models. The most important climate and landcover predictors were mean temperature diurnal range (i.e., average monthly differences between daily high and low temperatures) and proportion of area classified as pasture. Ensemble model concordance identified approximately 31,300 km2 of potential Plains Spotted Skunk habitat primarily in eastern South Dakota and between the watersheds of the Missouri and James rivers. Our results offer insights that can guide conservation and inform effective management strategies for conserving Plains Spotted Skunk populations in the northern Great Plains. The promotion of low-intensity agricultural practices such as maintaining pastures, farm buildings, fences rows, and the management of woodland encroachment may improve habitat suitability and facilitate the recovery of plains spotted skunks in the region.

Effect of intercropping apple trees with basil (Ocimum basilicum) or French marigold (Tagetes patula) on the rosy apple aphid regulation (Dysaphis plantaginea) and the abundance of its natural enemies.

In a global context of pesticide reduction, the sustainable management of aphids is a major challenge in maintaining economically viable fruit production. Intercropping with companion plants (CPs) that emit volatile organic compounds (VOCs) with repellent or attractive properties could be successful in the laboratory. Still, their effects on the orchard have been little documented. We tested in 2018 and 2019 the hypotheses that the introduction of basil or French marigold, decreases the populations of Dysaphis plantaginea Passerini, the rosy apple aphid (RAA) and increases the abundance of its natural enemies (NEs) in an apple orchard in the south of France. Laboratory tests confirmed that both CPs altered RAA reproduction performance. In orchards, they attracted more NEs around the pots and at some dates in the aphid colonies near the pots in both years (apart from basil in 2019), without a significant reduction in aphid populations in 2018. In contrast, in 2019, the number and spatial expansion of aphid colonies were significantly lower, close to basil. Further investigation is needed to disentangle the mechanisms explaining the observed effects (e.g., repellent action in autumn, etc.) but the results highlight the potential of CPs to control aphids in orchards and contribute to agroecological production of apple. Thus, this study shows the potential of CPs in a strategy combining aphid repellency and NEs attraction to control aphids in orchards, provided that CP installation lasts over several consecutive years. © 2024 Society of Chemical Industry.

Dietary zinc supplementation inhibits bacterial plasmid conjugation in vitro by regulating plasmid replication (rep) and transfer (tra) genes.

Humans use dietary supplements for several intended effects, such as supplementing malnutrition. While these compounds have been developed for host end benefits, their ancillary impact on the gut microbiota remains unclear. The human gut has been proposed as a reservoir for the prevalent lateral transfer of antimicrobial resistance and virulence genes in bacteria through plasmid conjugation. Here, we studied the effect of dietary zinc supplements on the incidence of plasmid conjugation in vitro. Supplement effects were analyzed through standardized broth conjugation assays. The avian pathogenic Escherichia coli (APEC) strain APEC-O2-211 was a donor of the multidrug resistance plasmid pAPEC-O2-211A-ColV, and the human commensal isolate E. coli HS-4 was the plasmid-free recipient. Bacterial strains were standardized and mixed 1:1 and supplemented 1:10 with water, or zinc derived from either commercial zinc supplements or zinc gluconate reagent at varying concentrations. We observed a significant reduction in donors, recipients, and transconjugant populations in conjugations supplemented with zinc, with a dose-dependent relationship. Additionally, we observed a significant reduction (P < 0.05) in log conjugation efficiency in zinc-treated reactions. Upregulation of the mRNA for the plasmid replication initiation gene repA and the subset of transfer genes M, J, E, K, B, P, C, W, U, N, F, Q, D, I, and X was observed. Furthermore, we observed a downregulation of the conjugal propilin gene traA and the entry exclusion gene traS. This study demonstrates the effect of dietary zinc supplements on the conjugal transfer of a multidrug resistance plasmid between pathogenic and commensal bacteria during in vitro conditions.IMPORTANCEThis study identifies dietary zinc supplementation as a potential novel intervention for mitigating the emergence of multidrug resistance in bacteria, thus preventing antibiotic treatment failure and death in patients and animals. Further studies are required to determine the applicability of this approach in an in vivo model.

Field Demonstration of Indigenous Strains Bacillus thuringiensis and Beauveria bassiana for Sustainable Management of Spodoptera litura in Groundnut

This study by Krishi Vigyan Kendra, Nellore, evaluates the efficacy of biopesticides Bacillus thuringiensis (Bt) and Beauveria bassiana formulations against S. litura compared to conventional insecticides over two growing seasons (2018-19 and 2019-20). Twenty Front Line Demonstrations (FLDs) involving 20 farmers were conducted, with treatments applied when leaf damage exceeded 25%. Results indicated significant reductions in leaf damage (8.40% for biopesticides vs. 8.89% for insecticides) and larval populations. Specifically, larval counts decreased substantially after treatment, with average counts at 50 DAS dropping from 21.29 (FP) to 3.37 (Demo) in 2018-19 and from 22.15 (FP) to 3.53 (Demo) in 2019-20. Economic analysis revealed comparable net returns and benefit-cost ratios for both treatments (1.92 and 1.93 for biopesticides and insecticides, respectively). These findings support the economic viability of adopting biopesticide, promoting sustainable agricultural practices and profitability in groundnut cultivation.

Rational cuts? The local impact of closing undersized schools

The availability of public education services can influence residential choices. Therefore, policies aimed at ‘rationalising’ service provision by reducing the number of undersized nodes in the public school network can lead to population decline, especially in spatially isolated areas lacking valid alternatives to the removed services. This paper examines the demographic and income effects of primary school closures by exploiting an Italian education reform that resulted in the contraction of the school network. We assess whether school closures impact households’ residential choices, over and above preexisting negative population trends that motivate school closures. Our findings indicate that municipalities affected by school closures experience significant reductions in population and income. The effect is primarily driven by peripheral municipalities located far away from economic centres and distant from the next available primary school. This evidence indicates that school ‘rationalisation policies’, by fostering depopulation of peripheral areas, have an influence on the spatial distribution of households and income, thus affecting territorial disparities.

Kif1a and intact microtubules maintain synaptic-vesicle populations at ribbon synapses in zebrafish hair cells.

Sensory hair cells of the inner ear utilize specialized ribbon synapses to transmit sensory stimuli to the central nervous system. This transmission necessitates rapid and sustained neurotransmitter release, which depends on a large pool of synaptic vesicles at the hair-cell presynapse. While previous work in neurons has shown that kinesin motor proteins traffic synaptic material along microtubules to the presynapse, the mechanisms of this process in hair cells remain unclear. Our study demonstrates that the kinesin motor protein Kif1a, along with an intact microtubule network, is essential for enriching synaptic vesicles at the presynapse in hair cells. Through genetic and pharmacological approaches, we disrupt Kif1a function and impair microtubule networks in hair cells of the zebrafish lateral-line system. These manipulations led to a significant reduction in synaptic-vesicle populations at the presynapse in hair cells. Using electron microscopy, in vivo calcium imaging, and electrophysiology, we show that a diminished supply of synaptic vesicles adversely affects ribbon-synapse function. Kif1aamutants exhibit dramatic reductions in spontaneous vesicle release and evoked postsynaptic calcium responses. Furthermore, kif1aamutants exhibit impaired rheotaxis, a behaviour reliant on the ability of hair cells in the lateral line to respond to sustained flow stimuli. Overall, our results demonstrate that Kif1a-mediated microtubule transport is critical to enrich synaptic vesicles at the active zone, a process that is vital for proper ribbon-synapse function in hair cells. KEY POINTS: Kif1a mRNAs are present in zebrafish hair cells. Loss of Kif1a disrupts the enrichment of synaptic vesicles at ribbon synapses. Disruption of microtubules depletes synaptic vesicles at ribbon synapses. Kif1aa mutants have impaired ribbon-synapse and sensory-system function.

Evaluation of Compost and Manure Amendments for Suppressing Heterodera glycines.

Soybean cyst nematode (SCN) is a major pest of soybean crops, causing significant yield losses and economic impact. Current management strategies primarily rely on resistant varieties, cover crops, and seed treatments. In addition, there is a growing interest in developing sustainable, ecologically based approaches to integrate SCN risk reduction into soybean production systems. This study aimed to evaluate the efficacy of various compost and manure amendments in suppressing SCN populations and promoting soybean productivity. An in vitro egg hatching assay was conducted to screen the inhibitory effects of different compost and manure extracts on SCN egg hatching. Results indicated that poultry manure, Layer Ash Blend, and swine manure extracts significantly inhibited SCN hatching compared with other treatments across multiple time points. Greenhouse trials further validated the effectiveness of Layer Manure, poultry manure, High Carbon Dairy Doo, and Seed Starter 101 in suppressing SCN cysts, eggs, and juveniles. A field microplot trial confirmed the potential of Layer Ash Blend and poultry manure in SCN management, with significant reductions in SCN populations and increased soybean yields. The study also investigated the impact of these amendments on promoting the population of bacterivorous and frugivorous nematodes, contributing to a biological diverse soil ecosystem. Overall, the results indicate that amending SCN-infested soil with specific compost or manure formulations can effectively suppress nematode populations while improving soybean productivity. These findings contribute to the development of sustainable strategies for SCN management in soybean production systems.

Efficacy of Botanicals and Insecticides against Whitefly, Bemisia tabaci Gennadius (Homoptera; Aleyrodidae) in Mungbean

Background: Mungbean is the major pulse crop of India. Pulse constitute the major source of dietary protein; therefore, it has ability to fulfil required protein recommended dietary allowance for vegetarian population of India. Pulse crop attack more than 200 insect pests. Methods: Efficacy test of Botanicals and Insecticides viz., Kaner powder, Garlic extract, Azadirectin 1500 ppm, Dasparni Ark, flonicamid, thiamethoxam, Imidacloprid and Dimethoate against B. tabaci was conducted in mungbean during Kharif 2022-2023 at Students’ Instructional Farm, Acharya Narendra Deva University of Agriculture and Technology, Kumarganj, Ayodhya (UP), India under field conditions with nine treatements including control in three replication. Result: The results demonstrated that Thiamethoxam 25 WG (50 g a.i./ha) was the most effective insecticide among all treatments, with a significant population reduction above control, followed by Imidacloprid 70 WG (5ml/l). Among the botanicals, Azadirectin 1500 ppm (5 ml/l) was the most effective against whitefly infestation in mungbean and could be applied as an eco-friendly alternative to conventional pesticides for whitefly management.

Linear Sources and Anisotropic Scattering in the Random Ray Method

An enhanced implementation of the random ray method (TRRM), a stochastic adaptation of the method of characteristics, is presented. This implementation generalizes from a traditional flat source (FS) approximation to a linear source (LS) approximation, and from the standard isotropic scattering approximation to an anisotropic approximation, up to P3. On the two-dimensional C5G7 benchmark, LS alone enables a 1.4× and 1.7× enhancement in run time for parallel and serial executions, respectively, without compromising accuracy. Further testing on the three-dimensional C5G7 Rodded B benchmark demonstrates that LS enables significant axial coarsening and reduction in ray populations. This results in a 5.3× speedup in run time while still offering comparable accuracy. On the Babcock and Wilcox 1484 Core II benchmark, incorporating anisotropic scattering in TRRM up to P3 with a FS decreased keff errors (~110 pcm) and maximum and average pin power errors. LS with anisotropic scattering (LSPN), showed similarly improved keff errors while benefiting from a coarser mesh. The linear isotropic flat anisotropic (LIFA) method, relative to LSPN, offers further run time and memory savings of 4.1× and 1.6×, respectively, for P3, while maintaining comparable accuracy to anisotropic FS on more refined meshes.

Modeling long-term, stage-structured dynamics of Tribolium castaneum (Coleoptera: Tenebrionidae) at food facilities with and without two types of long-lasting insecticide-incorporated netting.

The red flour beetle, Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae), is a cosmopolitan and destructive external-infesting pest at many food facilities. The use of deltamethrin- and α-cypermethrin-incorporated long-lasting insecticide-incorporated netting (LLIN) has shown incredible promise for the management of stored product insects. However, it is unknown how LLIN deployed within food facilities may affect the long-term population dynamics of T. castaneum compared to populations where no LLIN is present. Exposure to LLIN has been shown to affect mortality in the current generation and decrease progeny production in the subsequent generation. Thus, we modeled the long-term population dynamics of T. castaneum at food facilities over 15 generations by incorporating realistic estimates for mortality and progeny reduction after contact with LLIN compared to baseline growth by the species. We parameterized the model with estimates from the literature and used a four-stage structured population (eggs, larvae, pupae, and adults). The model was implemented using the package popbio in R. Our models suggest that deploying LLIN led to significant population reductions based on the estimates of mortality and progeny reduction from prior work, whereas the baseline model exhibited exponential population growth. In addition, there were differences in the frequencies of each life stage under each scenario modeled. As a result, it appears deploying LLIN may contribute to the local extirpation of T. castaneum within as few as 15 generations. Our work contributes to a growing literature about the effectiveness of incorporating LLIN into existing pest management programs for managing stored product insects in food facilities.

Impact of Long-Term Pyriproxyfen Exposure on the Genetic Structure and Diversity of Aedes aegypti and Aedes albopictus in Manaus, Amazonas, Brazil.

Aedes aegypti and Aedes albopictus are responsible for transmitting major human arboviruses such as Dengue, Zika, and Chikungunya, posing a global threat to public health. The lack of etiological treatments and efficient vaccines makes vector control strategies essential for reducing vector population density and interrupting the pathogen transmission cycle. This study evaluated the impact of long-term pyriproxyfen exposure on the genetic structure and diversity of Ae. aegypti and Ae. albopictus mosquito populations. The study was conducted in Manaus, Amazonas, Brazil, where pyriproxyfen dissemination stations have been monitored since 2014 up to the present day. Double digest restriction-site associated DNA sequencing was performed, revealing that despite significant local population reductions by dissemination stations with pyriproxyfen in various locations in Brazil, focal intervention has no significant impact on the population stratification of these vectors in urban scenarios. The genetic structuring level of Ae. aegypti suggests it is more stratified and directly affected by pyriproxyfen intervention, while for Ae. albopictus exhibits a more homogeneous and less structured population. The results suggest that although slight differences are observed among mosquito subpopulations, intervention focused on neighborhoods in a capital city is not efficient in terms of genetic structuring, indicating that larger-scale pyriproxyfen interventions should be considered for more effective urban mosquito control.

Host-feeding preferences and temperature shape the dynamics of West Nile virus: A mathematical model to predict the impacts of vector-host interactions and vector management on [formula omitted]

West Nile virus (WNV) is prevalent across the United States, but its transmission patterns and spatio-temporal intensity vary significantly, particularly in the Eastern United States. For instance, Chicago has long been a hotspot for WNV cases due to its high cumulative incidence of infection, with the number of cases varying considerably from year to year. The abilities of host species to maintain and disseminate WNV, along with eco-epidemiological factors that influence vector-host contact rates underlie WNV transmission potential. There is growing evidence that several vectors exhibit strong feeding preferences towards different host communities. In our research study, we construct a process based weather driven ordinary differential equation (ODE) model to understand the impact of one vector species (Culex pipiens), its preferred avian and non-preferred human hosts on the basic reproduction number (R0). In developing this WNV transmission model, we account for the feeding index, which is defined as the relative preference of the vectors for taking blood meals from a competent avian host versus a non-competent mammalian host. We also include continuous introduction of infected agents into the model during the simulations as the introduction of WNV is not a single event phenomenon. We derive an analytic form of R0 to predict the conditions under which there will be an outbreak of WNV and the relationship between the feeding index and the efficacy of adulticide is highly nonlinear. In our mechanistic model, we also demonstrate that adulticide treatments produced significant reductions in the Culex pipiens population. Sensitivity analysis demonstrates that feeding index and rate of introduction of infected agents are two important factors beside the efficacy of adulticide. We validate our model by comparing simulations to surveillance data collected for the Culex pipiens complex in Cook County, Illinois, USA. Our results reveal that the interaction between the feeding index and mosquito abatement strategy is intricate, especially considering the fluctuating temperature conditions. This induces heterogeneous transmission patterns that need to be incorporated when modelling multi-host, multi-vector transmission models.

Human response to the Younger Dryas along the southern North Sea basin, Northwest Europe

Currently in NW Europe little is known about the human response to the extensive cold reversal at the end of the Pleistocene, the Younger Dryas (ca. 12,850 till ca. 11,650 cal BP), mainly due to the poor chronological resolution of the archaeological sites belonging to the Ahrensburgian Culture. Here we present a series of 33 radiocarbon dates performed on the seminal cave site of Remouchamps, situated in the Belgian Meuse basin. Combined with a revision of the available radiocarbon evidence along the southern North Sea basin (Belgium, southern Netherlands, western Germany), it is suggested that the first half of the Younger Dryas, characterized as extremely cold and wet, faced a significant population reduction. Repopulation started around the middle of the Younger Dryas, from ca. 12,200 cal BP onward, probably in response to a slight climatic improvement leading to somewhat warmer summers. This might be considered a prelude to the subsequent population boost of the Early Holocene (Mesolithic).

Process optimization of thermosonicated modhusuleng (polygonum microcephalum) leaf juice for quality enhancement using response surface methodology

The present study investigated the impacts of pasteurization and thermosonication on various aspects of modhusuleng (Polygonum microcephalum) leaf juice, including its physico-chemical, functional, and microbial attributes (total plate count, yeast and mold count). Juices underwent thermosonic treatments at varied durations (30, 45, and 60 min) and temperatures (30, 40, and 50 °C), utilizing two distinct frequencies (33 and 44 kHz). The application of pasteurization (PS) and thermosonication (TS) did not exhibit any noticeable effects on pH, total soluble solids (TSS), or titratable acidity (TA). Post TS, there were enhancements in antioxidant activity, total phenolic content (TPC), total flavonoid content (TFC), cloudiness value, browning index, total carotenoid content, and chlorophyll content. However, the ascorbic acid content in the leaf juices decreased post TS. Process optimization was carried out through the application of response surface methodology (RSM). For 33 kHz, the predicted values were - Antioxidant - 68.23 %, TPC - 183.11 mg GAE/100 mL, TFC - 3.15 mg QE/mL, and Ascorbic acid - 24.45, while for 44 kHz, the values were obtained as - Antioxidant - 60.80 %, TPC - 212.97 mg GAE/100 mL, TFC - 3.40 mg QE/mL, and Ascorbic acid - 25.53. The model's suitability is highlighted by the small difference between the expected and actual values. The results revealed that leaf juice samples treated at 50 °C with a frequency of 44 kHz for 60 min exhibited higher TPC, TFC, and antioxidant activity when compared to samples subjected to alternative temperature and frequency conditions. TS also led to a significant reduction in bacterial populations in the juices. While thermal treatment rendered the microbes inert, it adversely impacted the quality indices. The study suggests that modhusuleng juice quality features can be preserved even after undergoing thermosonic processing. TS is suggested as a favorable technique for modhusuleng leaf juice processing, given its potential to enhance antioxidant activity, preserve quality features, and reduce bacterial populations.

Integrative analysis of single-cell RNA-seq and gut microbiome metabarcoding data elucidates macrophage dysfunction in mice with DSS-induced ulcerative colitis

Ulcerative colitis (UC) is a significant inflammatory bowel disease caused by an abnormal immune response to gut microbes. However, there are still gaps in our understanding of how immune and metabolic changes specifically contribute to this disease. Our research aims to address this gap by examining mouse colons after inducing ulcerative colitis-like symptoms. Employing single-cell RNA-seq and 16 s rRNA amplicon sequencing to analyze distinct cell clusters and microbiomes in the mouse colon at different time points after induction with dextran sodium sulfate. We observe a significant reduction in epithelial populations during acute colitis, indicating tissue damage, with a partial recovery observed in chronic inflammation. Analyses of cell-cell interactions demonstrate shifts in networking patterns among different cell types during disease progression. Notably, macrophage phenotypes exhibit diversity, with a pronounced polarization towards the pro-inflammatory M1 phenotype in chronic conditions, suggesting the role of macrophage heterogeneity in disease severity. Increased expression of Nampt and NOX2 complex subunits in chronic UC macrophages contributes to the inflammatory processes. The chronic UC microbiome exhibits reduced taxonomic diversity compared to healthy conditions and acute UC. The study also highlights the role of T cell differentiation in the context of dysbiosis and its implications in colitis progression, emphasizing the need for targeted interventions to modulate the inflammatory response and immune balance in colitis.

Integrating Metarhizium anisopliae entomopathogenic fungi with border cropping reduces black bean aphids (Aphis fabae) damage and enhances yield and quality of French bean

French bean growers, rely mainly on pesticides for pest management. The acceptable tolerance for pesticides residue in French beans is a major concern and has led to several tonnes of the crop continuously rejected and listed as unsafe for human consumption. There is growing demand for alternative approaches and products that are effective at managing pests without the side-effects associated with reliance on pesticides. A field study to determine the combined effects of Metarhizium anisopliae, (Metarril WP E9 and Biomagic) biopesticides and border crops (Sunflower and wheat) on aphid population, damage severity, growth, yield and quality of French bean. A two-factor experiment was conducted at the Egerton University, Kenya. First factor included two border crops (sunflower and wheat) and no border crop (control). Second factor included spraying Metarril WPE9 (2 × 108 cfu/g), Biomagic (2 × 108 cfu/ml) biopesticides, alpha-cypermethrin (synthetic insecticide) and water. Data on growth, yield and quality parameters were collected and analyzed using the SAS version 9.4M8. Results showed that M. anisopliae and border crop significantly (p < 0.0005) enhanced growth, yield and quality of French bean in both seasons. French bean grown with wheat or sunflower borders showed a significant reduction in aphid population (p < 0.0001) and damage severity (p < 0.0001) when sprayed with various treatments compared to the control. Plots with wheat border caused an increase in collar diameter of French bean. The plots (Metarril and wheat border) caused a 4 % and 5 % increase in marketable yield, a 2 % and 12 % reduction in non-marketable yield. To exploit the benefits of biopesticides, the study recommends their integration with and border crops. Thus, French bean growers could benefit more from fungal-based biopesticides in aphid-IPM approach, as it reduces pre-harvest intervals and residues compared to synthetic insecticides.

Compatibility of the Entomopathogenic Fungus Metarhizium anisopliae (Ascomycota: Hypocreales) and the Predatory Coccinellid Menochilus sexmaculatus (Col.: Coccinellidae) for Controlling Aphis gossypii (Hem.: Aphididae).

Metarhizium anisopliae (Ascomycota: Hypocreales) is an entomopathogenic fungus considered a key factor in developing integrated management of several insect pests on a variety of crops. The predatory coccinellid, Menochilus sexmaculatus (Col.: Coccinellidae), is also an important natural enemy that must be conserved for effective aphid control. Laboratory studies were conducted under controlled conditions to investigate the interaction between M. anisopliae isolate IRN. 1 and the coccinellid predator M. sexmaculatus in combating Aphis gossypii Glover (Hem.: Aphididae). The combined application of M. sexmaculatus and M. anisopliae led to significant reduction in aphid populations. The foraging behavior of M. sexmaculatus notably facilitated the dispersion of M. anisopliae conidia to uninfected plants, resulting 54 ± 1.3% decrease in aphid density after 10days. In both choice and non-choice experiments, female adult M. sexmaculatus to fungus-infected aphids was offered as prey and avoided as a food source during all starvation periods. However, live and dead non-fungus-infected aphids were fed upon. The result revealed the compatibility between M. sexmaculatus and M. anisopliae, which may provide a sustainable strategy for the effective management of A. gossypii in a cropping system.

Long‐term effects of management intensity and bioclimatic variables on leatherjacket (Tipula paludosa Meigen) populations at farm scale

AbstractLeatherjackets (Tipula spp.) are soil‐dwelling pests associated with agriculture. Land management decisions made at farm scale can have subsequent effects on their populations. Between 1980 and 2020, surveys were conducted across Scotland to collect field histories and larval population data from grassland farms. To assess the impact of management and bioclimatic factors on leatherjacket occurrence over time, this study investigated data from fields continuously sampled between 2009 and 2018. We utilized a Generalized Linear Mixed‐Effect Model on a dataset of 61 fields on 19 farms. Results indicated three significant factors affecting larval populations; field size, grazing type and application of insecticides or herbicides (referred to collectively as pesticides). Larval populations were significantly lower in fields that were larger in size and under sheep grazing, compared to no grazing. Pesticide application also caused a significant reduction in larval populations. Management variables were amalgamated to create a Management Intensity Index, revealing significantly increased larval populations under low‐management systems. These results, coupled with significant effects of bioclimatic variables, pinpoint predictive signals for high infestations and potential routes for control strategies.