Cover crops offer numerous benefits to the soil, including pest, pathogen suppression and enhanced fertility. Focussing on fields used for Narcissus production as a model, the potential of different cover crop treatments to suppress plant-parasitic nematodes while safeguarding beneficial nematode communities was evaluated. The root lesion nematode species, Pratylenchus penetrans, is known to significantly reduce Narcissus yields, a challenge further exacerbated by limited chemical control options and restricted land availability to deploy effective crop rotation. French marigold, oilseed radish, Phacelia, Japanese oats, alfalfa, and forage chicory were evaluated in two experiments under greenhouse conditions to assess their suitability as hosts for P. penetrans based on the nematode reproduction factor (Rf). Phacelia and Japanese oat were rated as maintenance hosts (1 < Rf < 2) while the remaining cover crops were identified as poor hosts (0.15 < Rf < 1). Thereafter, three field experiments assessed the effects of the same cover crop treatments, plus Indian mustard, on the abundance of Pratylenchus, Aphelenchus, Aphelenchoides spp., and bacterivore nematodes. Sampling occurred before sowing of the cover crop, three months after sowing and six weeks post-incorporation of the mature cover crop. Four of the tested cover crops (French marigold, oilseed radish, forage chicory and alfalfa) significantly reduced the abundance of Pratylenchus spp., by 53-75 % across all three experiments. Phacelia and Japanese oats had no effect, while Indian mustard increased the abundance of Pratylenchus spp., by 113-319 % across all experiments. Oilseed radish and Indian mustard increased the abundance of bacterivore nematodes, with oilseed radish showing the greatest increase of 335 %. Using 18S rRNA amplicon sequencing, cover crops showed no adverse effects on alpha and beta nematode diversity, while cover crop incorporation resulted in higher enrichment and lower structure indices. These findings strongly suggest that French marigold, oilseed radish, forage chicory, and alfalfa are potential options for managing Pratylenchus spp. without adverse effects on non-target beneficial soil nematode communities. Understanding cover crop-nematode interactions can expand their use beyond current production systems. This study offers a first step towards selecting cover crops that maintain/promote beneficial nematodes, support soil health restoration, and suppress Pratylenchus spp. in crops that form a typical UK arable rotation.

Festulolium hybrids are cool-season forage grasses that form symbiotic relationships with the fungus Epichloë uncinata, which produces loline alkaloids that protect the host from herbivores. This study evaluated the nematotoxicity of shoot and root extracts of Festulolium loliaceum against the stubby root nematode Trichodorus primitivus. Methanolic root and shoot extracts from plants aged 8, 12, 16, and 20 weeks were tested in vitro at five concentrations (312.5-5000 µg mL-1) over 24, 48, and 72 h. Nematode immobility, mortality, and phytochemical profiles, including flavonoids, loline alkaloids, and phenols, were quantified. Extracts from shoots caused significant concentration and time-dependent immobility of T. primitivus (p = 0.001), reaching ≥90% at 5000 µg mL-1 after 72 h in 8-12-week-old plants. Endophyte presence enhanced nematotoxicity, where LD50 values for E+ roots were two-fold lower at 12 weeks and fifty-fold lower at 20 weeks compared with E- root extracts. Shoot extracts of E+ grass had the highest nematicidal activity at 8 weeks, with a significantly lower LD50 value than E- (p < 0.05). Loline alkaloid concentrations increased with plant age, while flavonoids and phenols declined. Nematotoxicity of F. loliaceum extracts was strongly influenced by plant age and endophyte presence. Younger E+ shoots produced the most potent shoot extracts, whereas older plants produced the most potent root extracts. Flavonoid content was negatively correlated with shoot biomass (R = -0.94, p < 0.001). Similarly, phenol content was negatively correlated to both root biomass (R = -0.79, p < 0.001) and shoot biomass (R = -0.67, p < 0.005).

Stubby root nematodes (SRN)-(Trichodorus and Paratrichodorus spp.) are economically important plant parasitic nematodes (PPNs) in east England and have been reported to cause up to 50% root yield reduction in sugar beet (Beta vulgaris). The banning of nematicides such as Vydate (oxamyl) due to environmental concerns limits the management options available to farmers for the management of this nematode. Cover crops (CCs) present a practical option for farmers to manage nematodes whilst enhancing other soil properties such as structure, organic matter content and soil biodiversity, which contributes to the overall soil health. This study evaluated the population dynamics of SRN in field rotations with cover crops. The effect of cover cropping on the yield and quality of follow-up crop, sugar beet, was also evaluated. Field experiments were initiated at two sites in England: Bury St Edmunds, Suffolk (site 1) and Docking, Norfolk (site 2). The cover crops evaluated were-Indian mustard (Brassica juncea), oilseed radish (Raphanus sativus), daikon radish (Raphanus sativus var. longipinnatus), Festuca-lolium hybrid grass (Festulolium loliaceum) with endophyte (E+) and without (E-), Italian rye grass (Lolium multiflorum), phacelia (Phacelia tanacetifolia) and opium poppy (Papaver somniferum). At site 1, plots drilled with brassica cover crops, Indian mustard and oilseed radish, had significantly lower SRN reproduction factor (Rf) (p < .05) compared to the fallow control and daikon radish. In site 2, plots drilled with the cover crops-Italian rye grass, Indian mustard, grass without endophyte (E-) or left fallow and undisturbed had a significantly higher Rf (p < .05) compared to plots with phacelia, opium poppy, and disturbed or sterile fallows. Sugar beet root fanging (%) and root soil tare (%) were lower in plots that had lower SRN reproduction, that is, phacelia, opium poppy, sterile fallow, and disturbed fallow. Environmental variables such as rainfall and soil temperature also influenced SRN densities at different sampling points where SRN increased with increasing rain and decreasing soil temperatures. Results from this study indicate that under field conditions the population dynamics of SRN are influenced by multiple factors such as the host status of the CCs grown, weed occurence which serve as alternative hosts as SRN are polyphagous in nature, soil temperature, rainfall, and soil disturbance. It was also clear that multiplication rate of SRN in CCs such as phacelia and opium poppy was lower despite SRN being able to multiply in all cover crops tested in this study.

This study investigated the potential of utilising cool season grasses naturally associated with Epichloë endophytic fungi for the management of plant-parasitic stubby root nematodes (Trichodorus spp. and Paratrichodorus spp.). Stubby root nematodes are economically important in East England where they cause docking disorder in sugar beet which causes up to 50% root yield reduction. The lack of chemical nematicides for the management of stubby root nematodes due to environmental concerns warrants the development of more eco-friendly measures. Epichloë fungal endophytes are known to confer protection from herbivory to their cool-season grass hosts, via the production of alkaloidal compounds. Several Epichloë species are known to produce loline alkaloids, a group of compounds known for their insecticidal and insect-deterrent properties. Lolines have also been reported to inhibit nematode mobility, egg hatching and mortality. In this study, Festulolium loliaceum and its associated endophyte Epichloë uncinata, known for its production of loline alkaloids, were investigated for their efficacy in suppressing stubby root nematodes. In a field experiment in Docking, Norfolk, England, endophyte-infected grasses significantly reduced the reproduction of stubby root nematodes by seven times compared to endophyte-free grass associations. Laboratory experiments using extracts from shoots and roots of F. loliaceum plants showed that both endophyte-infected and endophyte-free plants could immobilize nematodes. Age, source of extract and extract concentration had a significant effect on the nematocidal activity. Extracts from younger grasses were more potent compared to older grasses, where shoot extracts from 8-week-old endophyte-infected grass plants had six times lower LD50 values compared to 20-week-old grass plants. A contrasting effect was found for grass root extracts where roots from older plants were more potent than extracts from roots from younger plants, and had lower potency compared to shoot extracts. Further laboratory experiments showed that artificial wounding of endophyte-infected F. loliaceum plants elevated the loline alkaloids in the regrowth tissue within the first 11 days. Nematicidal activity of extracts from this regrowth tissue was significantly greater as compared to extracts from unwounded grass tissue. Overall, the results from this study suggest that endophyte-infected grasses could serve as a potential cultural management strategy for stubby root nematodes in a sugar beet crop rotation system. It is also evident that stubby root nematodes are sensitive to loline alkaloids produced from the grass-endophyte symbiosis used in this study, and this system could be optimised in the future to support nematode suppression under field conditions.

Pines are the most economically important trees in the world and, together with eucalyptus, they dominate commercial forests. But the success of a relatively small number of widely planted species, such as Pinus pinaster, the maritime pine, comes at a price. Pines are attractive to damaging pathogens and insect pests, including the pinewood nematode (PWN), Bursaphelenchus xylophilus, the causal agent of pine wilt disease (PWD). Originally described in Japan, PWD has caused widespread destruction to forests in countries such as China, Taiwan, Portugal, Spain and the United States. PWN causes irreparable damage to the vascular system of its pine hosts, leading to mortality within 3 months. Pine sawyer beetles (Monochamus spp.) are key vectors of PWD, introducing the PWN to healthy trees during feeding. Other organisms contribute to PWD spread and development, including bacteria, fungi and bark beetles. Control measures include tree felling to prevent vector transmission of PWN, insecticide treatments, trapping of Monochamus spp. and tree breeding for plant resistance. The PWN is a quarantine pathogen and subject to regular legislation and phytosanitary measures aimed at restricting movement and preventing introduction to new areas. Current research is investigating the use of biopesticides against PWN and Monochamus spp. This review examines the biology, epidemiology, impact and management of PWD through published research, grey literature and interviews with people directly involved in the management of the disease in Portugal. This review describes the global impact, biology and management of pine wilt disease and includes interviews with those directly involved in tackling the problem in Portugal.image

Plant parasitic nematodes (PPNs) have a negative impact on a broad range of UK-grown ornamental crops, including Narcissus. As a consequence of direct damage through infection and feeding, the nematodes Ditylenchus dipsaci, Pratylenchus penetrans, and Aphelenchoides subtenuis can cause a reduction in the viability, quality, and marketability of bulbs and flowers. Management practices such as lifting after two, three, and four years, limited rotations, and bulk handling predispose Narcissus to nematode attack. To mitigate the impact of PPNs, growers rely on pre-planting methods such as hot water treatment, quarantine/field sanitation, and nematode-free bulbs, as there are no available nematicides with label permission for use on Narcissus. However, these management options, coupled with the legislative removal of synthetic nematicides, are insufficient to manage PPNs of Narcissus. Furthermore, hot water treatment can damage bulbs, and the lack of available land for Narcissus production leads to constrained rotations. Plant parasitic nematodes and associated diseases infecting UK ornamental crop production are generally an understudied area. Here, we review the current status of nematodes associated with Narcissus in the UK, their pathogenicity and management, and highlight areas of potential research towards sustainable management of nematodes in Narcissus.

Summary Brassica plants naturally produce glucosinolates as secondary metabolites hydrolysed to biocidal isothiocyanates (ITCs). As such, they have the potential for nematode management through a strategy known as biofumigation. Pratylenchus penetrans causes significant yield losses in many important crops. Understanding the relative impact of different ITCs on the motility and mortality of this nematode species could provide some insights into the selection of relevant brassica biofumigants. The effects of 3.125, 6.25, 12.5, 25, and 50 μ g ml −1 of pure Allyl, 2-Phenylethyl and Benzyl ITCs on the motility and mortality of P. penetrans were evaluated in laboratory in vitro assays. Motility was assessed after incubating the nematodes in ITCs for 24, 48 and 72 h with distilled water as a negative control. Motile and non-motile nematodes were counted. After motility assessment at 72 h, nematodes were rinsed and incubated in water for 48 h, after which live and dead nematodes were counted. Nematodes were considered dead if they remained non-motile after probing with a picking needle. Nematode motility and mortality were significantly affected by the type of ITC, concentration and time of exposure. The number of non-motile nematodes increased with increasing concentration and time of exposure across all tested ITCs. The ED 50 values (concentration required to cause 50% non-motility) of Allyl, 2-Phenylethyl and Benzyl were 37.4, 12.8 and 8.6 μ g ml −1 after 24 h exposure. The ITC with potentially the greatest nematicidal effect was Benzyl (LD 50 = 3.2 μ g ml −1 ), followed by 2-Phenylethyl (LD 50 = 5.2 μ g ml −1 ), and Allyl (LD 50 = 9.9 μ g ml −1 ). The LD 50 of all ITCs were not different from the ED 50 after 72 h, meaning the effects of ITCs could be considered irreversible. This study suggests that brassica biofumigants that produce Benzyl, Allyl and 2-Phenylethyl ITCs are promising candidates for biofumigation of P. penetrans .

There is a growing interest in finding reliable methods for monitoring soil health using bioindicators. Free-living nematodes are an ideal indicator group because of their rapid response to changes in soil conditions. This UK study aims to assess their efficacy as bioindicators using two field experiments. In Experiment-1, the treatments included Farmyard Manure, Green Manure consisting of a mix of Raphanus sativus and Vicia sp., and Standard Practice serving as the control receiving N-fertiliser only. The same treatments, except Farmyard Manure, were compared in Experiment-2, which was on a sloping site with a different textured soil. Soil samples were collected twice during each crop season, in Spring and Autumn, for Experiment-1, and only in Autumn for Experiment-2. Ecological indices that categorise nematodes by feeding preference using morphological differences and life strategies (i.e. functional guilds) were calculated. Indices were compared with the abundance of nematode trophic groups to evaluate their use as soil indicators for understanding crop management practices and their legacy effects. Results showed that identification to trophic groups alone was not a sufficiently sensitive approach for assessing changes in the selected management practices. The variations among trophic groups and treatments within the same sampling period were significantly different for bacterivores, fungivores, predators, omnivores, and herbivores. These differences did not always cooccur within the same sampling period, with bacterivores and plant-parasites of economic importance showing greater responses. The food web analyses, calculated by applying the Enrichment Index and Structure Index, and Plant Parasite Index, provided a more sensitive indicator and allowed more effective diachronic monitoring. While using the composition of trophic groups appears to be an attractive solution, their application is best linked to quantifying short-term changes in soil condition and were not as well suited to longer-term soil health monitoring.

Collembolan ecomorphological groups (i.e., epiedaphic, hemiedaphic and euedaphic) have been proposed as bioindicators of soil health with potential to be applied in agricultural systems. While some studies have investigated disturbance gradients, there is a lack of monitoring studies showing trends over time evaluating changes in management posited to improve soil health. We investigated the status of a soil in an arable rotation following conversion to no-till. The response in abundance of Collembola ecomorphological groups, along with soil physicochemical properties, was monitored over 2 years, in two field experiments established on different soil types within the same field. The treatments were standard practice and green manure (GM) in both Experiments 1 and 2, and farmyard manure (FYM) in Experiment-1 only. Significant responses to treatments were mostly observed with euedaphic Collembola during the first year, but treatment effects were no longer evident in the second year. A decline in epiedaphic abundance was recorded in Year-2 in the GM treatment. A negative association was observed with total soil nitrogen and pH, while a positive association was observed between gravimetric water content and euedaphic Collembola abundance. This study demonstrated that euedaphic Collembola quickly responded to changes in management practice, but the impact of treatments was transient. The abundance of Collembola ecomorphological groups discriminated between short-term impacts but were an ineffective bioindicator of treatment effects over a two-year period suggesting that they may be best applied for monitoring short-term effects in response to intermittent inputs.

Every year, plant parasitic nematodes, one of the major groups of plant pathogens, cause a significant loss of crops worldwide. To mitigate crop yield losses caused by nematodes, an efficient nematode monitoring method is essential for plant and crop disease management. In other respects, efficient nematode detection contributes to medical research and drug discovery, as nematodes are model organisms. With the rapid development of computer technology, computer vision techniques provide a feasible solution for quantifying nematodes or nematode infections. In this paper, we survey and categorise the studies and available datasets on nematode detection through deep-learning models. To stimulate progress in related research, this survey presents the potential state-of-the-art object detection models, training techniques, optimisation techniques, and evaluation metrics for deep learning beginners. Moreover, seven state-of-the-art object detection models are validated on three public datasets and the AgriNema dataset for plant parasitic nematodes to construct a baseline for nematode detection.

Crop establishment in no-till arable systems benefits from soil health conducive for growth. Combined with the incorporation of crop residues and manures, no-till can influence soil organic carbon (SOC) and organic matter (SOM) dynamics, crop productivity and nutrient cycling. These processes are shaped by spatial and temporal factors including associated microbial activity. This study aimed to investigate the interaction between microbial and soil physicochemical properties during the transition from full-inversion to no-till soil management. Assessments were conducted over a two-year period and included a combination of soil microbial assays (microbial biomass carbon and nitrogen with physicochemical analyses, SOC, SOM, textural class, pH, gravimetric water content, and macronutrients). Two experiments were established within the same four-hectare field: one on a relatively level area (Experiment-1) and another on a slope (Experiment-2). Experiment-1 treatments consisted of Farmyard Manure (FYM and N-fertiliser), Green Manure (GM, Raphanus sativus and Vicia sp. mix) and Standard Practice (SP = Control, N-fertiliser only). Experiment-2 was a repeat of Experiment-1, but without the FYM treatment. Soil was sampled twice per crop season, in Spring and Autumn, in Experiment-1, and in Autumn only in Experiment-2. The results were influenced by spatial (i.e. where the same was collected from) and temporal (i.e. the time at which the same was collected) variations that were not always linked to management practices. This study demonstrated that the quantification of SOC and SOM were poor predictors of change in management practices over two years, while microbial biomass responded quickly to the incorporation of FYM. SOC and SOM were affected by soil texture, but not significantly by inputs, and were associated with extractable Ca2+ and total-N. Diachronic studies increase our understanding of biological and physicochemical dynamics in response to short-term change in soil management practices. This study emphasises the impact of soil texture within a single heterogenous field, and how it affects management outcomes. It highlights the importance of considering spatial differences to develop effective and sustainable agricultural solutions.

Summary Pratylenchus crenatus, P. neglectus, P. penetrans and P. thornei are globally the most commonly occurring species of root-lesion nematodes (RLN). Correct identification and quantification of these nematodes is important for strategic management interventions such as rotation choice and nematicide use. A real-time quantitative PCR can provide a fast and reliable alternative to morphological identification, which requires significant taxonomic experience. A TaqMan hydrolysis probe method based on the 28S rDNA D2-D3 expansion region was developed and validated for the identification and quantification of these four root-lesion nematode species. Standard curves for each target RLN species were generated by plotting known gene copy number, obtained by a ten-fold serial dilution of purified plasmids, with corresponding Ct values. Each standard curve had a strong linear correlation () between Ct value and gene copy number. There was consistent amplification of samples with target species from different geographic locations within the UK, whereas a lack of amplification was noted for selected non-target species: P. coffeae, P. pseudocoffeae, P. vulnus, P. fallax, Globodera rostochiensis, Meloidogyne hapla, Trichodorus primitivus and Bitylenchus hispaniensis. Specificity and sensitivity of the methods were confirmed by three experiments that explored different life stages, increasing the number of target species, and had mixed Pratylenchus samples. Finally, estimates obtained by qPCR methods were compared with counting carried out by microscopy showing a good correlation (). The TaqMan real-time PCR developed in this study provides a specific, fast and accurate quantification of P. crenatus, P. neglectus, P. penetrans and P. thornei.

Summary Brassicas contain glucosinolates (GSLs), which are converted into different isothiocyanates (ITCs) that possess biocidal activity. These different ITCs result in a range of toxicities to various target species. Laboratory assays were conducted to evaluate the sensitivity of stubby root nematodes (SRN), Trichodorus and Paratrichodorus spp., to three pure, commercially available ITCs, i.e., 2-phenylethyl (PEITC), allyl (AITC) and sulforaphane (SITC) at different concentrations (1.625, 3.125, 6.25, 12.5, 25 and 50 μg ml−1). The effect on nematode mobility was assessed after 24, 48 and 72 h. Mortality of SRN was assessed after 48 h incubation of the nematodes in distilled water post ITC treatment. Mortality for all ITCs at all tested concentrations was significantly higher than the controls, distilled water and 1% DMSO. Concentration and type of ITC had a significant effect on SRN mobility and mortality, whilst increase in exposure time did not significantly increase the immobility of SRN. The average 24 h ED50 (dose that resulted in 50% immobility) for SRN were 7, 5 and 44 μg ml−1, and the average LD50 (dose that resulted in 50% mortality) after 48 h recovery in distilled water was 7, 11 and 24.3 μg ml−1 for PEITC, AITC and SITC, respectively. SITC was significantly less potent compared to PEITC and AITC, which had LD50 values that were four times and two times lower, respectively. These results indicate the potential use of brassica associated with the tested ITC in the process of biofumigation for SRN suppression.

Claviceptaceous endophytic fungi in the genus Epichloë mostly form a symbiotic relationship with cool-season grasses. Epichloë spp. are capable of producing bioactive alkaloids such as peramines, lolines, ergot alkaloids, and indole-diterpenes, which protect the host plant from herbivory by animals, insects, and nematodes. The host also benefits from enhanced tolerance to abiotic stresses, such as salt, drought, waterlogging, cold, heavy metals, and low nitrogen stress. The bioactive alkaloids produced can have both direct and indirect effects towards plant parasitic nematodes. Direct interaction with nematodes’ motile stages can cause paralysis (nematostatic effect) or death (nematicidal effect). Indirectly, the metabolites may induce host immunity which inhibits feeding and subsequent nematode development. This review highlights the different mechanisms through which this interaction and the metabolites produced have been explored in the suppression of plant parasitic nematodes and also how the specific interactions between different grass genotypes and endophyte strains result in variable suppression of different nematode species. An understanding of the different grass–endophyte interactions and their successes and failures in suppressing various nematode species is essential to enable the proper selection of grass–endophyte combinations to identify the alkaloids produced, concentrations required, and determine which nematodes are sensitive to which specific alkaloids.

Prof. Simon R. Leather with giant aphid (This figure has also been used by Azevedo & Millman, 2020.) Prof. Simon R. Leather (Figure 1), BSc MBiol Hon.FRES PhD, was an Emeritus Professor at Harper Adams University when he passed away in 2021. Tributes have been paid to him soon after; he was a leading figure in the entomological and scientific community. As published on the web page of Harper Adams University, UK, on 29 September 2021, Simon described himself: "I am an applied entomologist, but by that I don't mean someone who can identify a huge number of species. I am not a taxonomist. Rather, I am a competent field entomologist who can recognise most insects to Order, some Orders to Family and within some families I am able to recognise individual species, especially if they are of economic importance.". Simon was a lot more than that. Over the years working with Simon and based on the information exchanged with people who knew him well when preparing this special issue, Simon was extremely dedicated to everything he did, a kind bright man ready to help. He was on the board of Annals of Applied Biology since 2005 as a Senior Editor and from 2015 until 2020 as the Editor-in-Chief, and stayed with Annals in 2021 as Senior Editor. We can all say that working with him was easy, he was ready to take action on anything and to provide the needed support the editors might needed. Three years have passed since Simon left us and this issue of Annals is a tribute to him. We decided to publish only papers in the field of Entomology and in this special issue Editorial we share with you some thoughts on Simon's work and life. Also, not to be missed, is the timely accompanying "Opinion" article "Don't Forget the Blogosphere" by Heinen et al. (2024), in a 'blog style' article piece, which also contains a bit more on Simon. We are pretty sure you are going to love it. As you will read below, and in the Heinen et al. (2024) accompanying article, Simon was passionate about science and entomology. He published over 200 articles plus several books, book chapters and was very active on social media sharing his experience, ideas, and thoughts with his followers, colleagues, friends and general audience, a contribution that we all are grateful. He kept a very active personal blog: "Don't Forget the Roundabouts" (https://simonleather.wordpress.com/). Simon, we miss you! Thank you! Ricardo A. Azevedo: I met Simon in person for the first time in 2008, at Rothamsted Research, when we had a Senior Editor's (SE) meeting (Figure 2), which was my very first one. I did not speak much, and spending the day with those guys was tremendous, and I easily came to admire them. Simon was a gentleman talking to me for quite a long time. I think it was his second SE's meeting. Working with Simon was easy and two things I liked a lot about him were that he was quick to reply to any messages and to solve problems. Over the years all the SEs left the board, new ones joined, and Simon and I were the two who remained from that first group that worked so well together for some 12 years. Then, Simon took the role of Editor-in-Chief (EiC) and what a great time we had. Very efficient, sharp and always positive, and keeping the relationship with the editors good but making sure we were all committed to the journal. During his last year as EiC I worked closely with him because I was going to take his place in the following year, and what a year it was! I learnt so much and Simon was once again a mentor to me. Despite my involvement with Annals since 2006, it was during those 7 months working closely to Simon that I truly realised the huge and demanding work of a EiC. I always made sure that I would arrive at the SE's meeting at least 1–2 h earlier because I knew Simon would be there and we would be able to talk about other things, not science or the journal. Whereas Simon was very active on social media, I was not, but he was the one who insisted that I should get involved because it would be good for the journal and for my own research. He was the very first one to follow me on Twitter! I also remember that Simon, Carol Millman (AAB), Andreas Pedersen (Wiley) and I had an Annals-Wiley quarterly catch-up meeting on 23 of September 2021; Simon took part in it and shared his comments as usual; he was clearly very tired, but he was there fully involved and dedicated to Annals. He passed away a few days later. What else can I say? In 2020, I proposed a new section called: "Editorial – Interviews", and the first person we interviewed was Simon (Azevedo & Millman, 2020). Please do read the article and you will get some more information about Simon in his own words. Simon, such a great and dear colleague. Tom W. Pope: I first met Simon when I applied to study for the M.Sc. in Applied Entomology at Imperial College London back in 1998. I still recall my first introduction to a Simon Leather office, full of the many and varied tasks (some would say clutter) he seemed to always have on the go at any one time (Figure 3). He always assured me that he was actually very organised, as his 11,000 book library and extensive reprint collection would seem to support. The other thing I recall was how friendly and welcoming Simon was, as a nervous prospective student, I quickly felt relaxed and able to talk about the course I had applied to study and my interests in entomology. I feel fortunate that I was able to keep this conversation with Simon going for the next 23 years. This conversation continued through my M.Sc. and then on to my Ph.D., where Simon was part of my advisory team, a post-doctoral role where Simon became a collaborator, and finally as a colleague when we both moved to Harper Adams in 2012. The 10 years working together with Simon at Harper Adams was a great experience, establishing the M.Sc. courses, the Jean Jackson Entomology Laboratory and associated research activities at the university. In all this, Simon provided unwavering support and encouragement whilst leaving the space for me to find my own way. I recognise how fortunate I was to meet Simon back in 1998 and the impact he had on my career but also that I am one of many who can say this. Simon was a brilliant entomologist whose academic achievements speak for themselves, but just as important are the positive impacts that he had on students, colleagues and anyone else who met him in person or online throughout his career. Andrew Wilcox: I first met Simon in 1992 when we both applied for an environment lecturer job at Harper Adams Agricultural College as it was known at the time. At the interviews, Simon was dressed in exactly the same manner as he always did, wearing blue jeans, a shirt and brown suede desert boots. I remember questioning if I was somewhat overdressed in my best suit as we had a glass of sherry in the Principal's office! I think we were both surprised at how interviews were conducted at Harper Adams in 1992. As it happens, neither Simon or I were offered the job—obviously desert boots and business suits did not cut it in a land of tweed! Simon then went off to undertake his seminal role as a lecturer at Imperial College at Silwood Park and I was offered the job at Harper Adams after the originally appointed candidate subsequently dropped out. Although I was generally aware of Simon's progress at Silwood Park, we never actually met again (despite me being a Silwood old boy) until 10 January 2012. This was the meeting where everything changed and the intention to move the successful Entomology M.Sc. courses from Imperial College to Harper Adams University was agreed. I was managing the taught postgraduate provision at the time and the job fell to me to compile the not insubstantial validation paperwork. Simon of course offered me his full support, but as we are all aware, university administration was not one of Simon's favourite activities. I recall asking Simon many complex questions during this period and receiving one or two word emails in response such as "okay" or "sounds good". We did, however, get the programmes successfully validated and welcomed our first M.Sc. Entomology cohort to Harper Adams in September 2012. By this time, I had been appointed Head of Department and I was able to resource the courses more effectively. The courses were very popular in their new home and the entomology section at Harper Adams has since continued to evolve, expand and thrive. Simon's unwavering dedication and drive are the key reasons why we have entomology at Harper Adams University and I am privileged to have worked with Simon (even though I did most of the paperwork) to create this proud legacy. Joe M. Roberts: Simon and I first corresponded when I was an undergraduate student studying forensic biology during 2011. I had emailed him to enquire about career opportunities in forensic entomology after attending a lecture on the subject at the Natural History Museum in London. His (characteristically short) reply was that there were no jobs in forensic entomology but that I should apply for the postgraduate entomology course he ran as there were lots of other entomology jobs out there! I decided that this course wasn't really for me and pursued a more chemistry-based postgraduate course in the hopes of still becoming a forensic scientist. Fast forward 12 months. Simon had relocated to Harper Adams University and I had realised that forensic science wasn't for me. Luckily, Simon had just advertised four Ph.D. studentships and one of these caught my eye as it would allow me to combine my newly found interest of entomology with chemistry. I submitted my application and was lucky enough to be offered the position in Simon's newly established lab at Harper Adams University. I spent the following 4 years working with Simon during my Ph.D. mostly trying to keep him on task during meetings and stop him from emptying cups of coffee onto my laptop (this happened once). He was a fantastic supervisor who always had time to chat about my work and offer advice when I asked. I was very fortunate to have someone as experienced as Simon guide me through the complex Ph.D. world and he encouraged me to be an independent thinker, ultimately inspiring me to become an academic. I now manage the courses that Simon established at Harper Adams University and am grateful for the many years of work he put into developing them. Simon's legacy lives on through the many hundreds of students that he taught during his extensive career — entomology is a better discipline because of him! (Figure 4). Carol A. Millman: I first met Simon in the 1990s, while he was working as a lecturer at Imperial College. He used to bring a bus load of students to our Entomology (afterwards named Biocontrol and IPM) group conferences. We got to know each other better when Simon became the Senior Editor for Entomology and Nematology papers submitted to Annals. We had a very tight knit group. At this time Martin Parry was the Editor-in-Chief, followed by Jari Valkonen. I was delighted when Jari retired from the Editorial Board in 2015, and Simon became the Editor-in-Chief. Simon was very calm and efficient. When Twitter took off, we called him the "Twitter King"; he could always be seen at our conferences busy tweeting at the back of the room and sending out details of every talk given during the day. Someone once said to me, he never even listens to the talks, he's always on his phone. How wrong you are, I replied, you should follow him on Twitter, then you will find out exactly what he is doing. He was a great advocate for both the journal and AAB, and cared very deeply about both. Even after he became ill, and during COVID, he still attended our virtual meetings, even as Ricardo mentioned, a few days before he passed away. Simon had a great impact on the Editorial Board and was always there for advice and assistance. The Senior Editors always worked very well together, and our annual meeting was a highlight of the year for all of us. I still think of him often, and he is sadly missed. Matthew A. Back: Simon joined Harper Adams in 2012. Although my research interests were slightly different to his, I was fully aware of the importance of his work within the sphere of Entomology. We worked together on courses and several research bids. Simon was unassuming, relaxed and easy to talk to. He could speak naturally on many topics, drawing upon his own experiences and anecdotes to create interest. Working with Simon on a BBSRC STARS project, to deliver a short course on crop protection to final year degree students, was a great pleasure and privilege. He went above and beyond to ensure that the students undertaking the course got the most out of their week; this included creating fun activities during evenings and at the weekend. Simon was extremely supportive to journals and learned societies, including the Association of Applied Biologists; he was the welcome steady hand, who knew exactly what he was doing. Finally, I cannot omit the time when Simon stayed back after work to show my daughter Emily (then 5 years old) our collections of moths and butterflies—she has never forgotten 'Professor Leather and all those cabinets of insects'! I miss seeing him around Harper Adams, with his flamboyant insect themed t-shirts and blue denim jeans. Gia – Guðbjörg I. Aradóttir: It is said that you will always remember how people made you feel over what they said or did. I first met Simon when he became my Ph.D. supervisor. I arrived at Imperial College's Silwood Park where he greeted me with his warm smile, making me feel very welcome and swept up in his enthusiasm for the day's activities. Through my Ph.D. and beyond he was a great colleague and mentor to me as so many others. He cared deeply about his students, their progress and wellbeing, and in one of our last conversations he told me how his advice to his students seeking employment was to look at where they would get good support and be valued and not just the academic ranking of an institution. In this as in so many areas he was ahead of the curve. Simon's scientific achievements stand for themselves and will continue to benefit generations to come, but for those of us that knew him the memory of a great man who was always engaged and engaging, his kindness, good humour and positivity will live on. Martin A. J. Parry: I was delighted to recruit Simon to the editorial board of Annals of Applied Biology. He quickly proved himself an efficient and diligent editor who worked hard to ensure the success of the journal. I enjoyed working with him and I was pleased but not surprised when Simon later became a Senior Editor and eventually Editor in Chief.

Abstract Potato cyst nematodes (PCN) are parasitic roundworms that cause unsustainable global crop loss in Solanaceous species. In Scotland, these pathogens threaten seed potato production which is both a key export for the country and the backbone of the UK potato industry. PCN are routinely controlled by host resistance genes which have been discovered for the main species of PCN in the UK. However, when market preferences request genotypes without resistance, PCN populations can thrive. Other promising control strategies exist but are not always applied in Scotland due to differing climate and agronomic practices. There are numerous implications for PCN presence in potato-growing land both during cultivation and within crop rotations. For example, if PCN are detected in statutory field testing, seed potatoes cannot be grown in that land, this results in reduced seed availability and increased grower costs if PCN-free land must be rented. Ultimately these increased grower costs will result in failure for businesses or will be distributed to the consumer through the supply chain. This case study aims to dissect the issues surrounding control of PCN in Scotland, highlighting the impact PCN have on the production line, from planting to consuming potatoes and potato products. Information © The Authors 2023

The culture media recommended for the isolation and enumeration of the Fusarium spp. lack selectivity for Fusarium graminearum. Five fungicides—Amistar® (250 g·L−1 azoxystrobin), Filan® (500 g·kg−1 boscalid), Comet® 200 (200 g·L−1 pyraclostrobin), Imtrex® (62.5 g·L−1 fluxapyroxad), Poraz® (450 g·L−1 prochloraz)—were investigated for their potential as selective inhibitors in culture media for the isolation of F. graminearum from soil and plant material. Based on the screening, fluxapyroxad was further tested for selective inhibition for the isolation of F. graminearum from soil. Additionally, selective media were compared for the isolation of F. graminearum from plant material. The fungicides tested did not prove to be effective inhibitors for the development of selective media. For the detection of F. graminearum in plant material, Czapek Dox propiconazole dichloran agar was found to be a better medium than Komada’s media, as the former resulted in colonies with darker pigmentation over a shorter incubation time and appeared to have a less inhibitory effect on F. graminearum growth.

Summary Globodera pallida is the most damaging pest of potato in the UK. This work underpins enhancement of a well-established, web-based scenario analysis tool for its management by recommending additions and modifications of its required inputs and a change in the basis of yield loss estimates. The required annual decline rate of the dormant egg population is determined at the individual field sample level to help define the required rotation length by comparing the viable egg content of recovered cysts to that of newly formed cysts for the same projected area. The mean annual decline was 20.4 ± 1.4% but ranged from 4.0 to 39.7% annum −1 at the field level. Further changes were based on meta-analysis of previous field trials. Spring rainfall in the region where a field is located and cultivar tolerance influence yield loss. Tolerance has proved difficult to define for many UK potato cultivars in field trials but uncertainty can be avoided without detriment by replacing it with determinacy integers. They are already determined to support optimisation of nitrogen application rates. Multiple linear regression estimates that loss caused by pre-plant populations of up to 20 viable eggs (g soil) −1 varies from ca 0.2 to 2.0% (viable egg) −1 (g soil) −1 depending on cultivar determinacy and spring rainfall. Reliability of the outcomes from scenario analysis requires validation in field trials with population densities over which planting is advisable.

Crop establishment in no-till arable systems benefits from favourable soil conditions. Combined with the incorporation of crop residues and manures, no-till can influence soil organic carbon (SOC) and organic matter (SOM) dynamics, crop productivity and nutrient cycling. These processes are shaped by spatial and temporal factors and associated microbial processes. There is a lack of diachronic large-scale field studies that include baseline data and capture seasonal variations in arable systems. This study aimed to investigate the interaction between microbial and soil physicochemical properties as they evolved over time during the transition from full-inversion to no-till soil management. It utilised a combination of soil microbial assays (microbial biomass carbon (MBC) and nitrogen (MBN) with bio-physico-chemical analyses (SOC and SOM quantification, textural class, pH, gravimetric water content (GWC), and macronutrients) to assess soil over two years. Two experiments were established within the same four-hectare field: one on a relatively level area (Experiment-1) and another on a slope (Experiment-2). Experiment-1 treatments consisted of Farmyard Manure (FYM), Green Manure (GM) and Standard Practice (SP = Control). Experiment-2 was a repeat of Experiment-1, but without the FYM treatment. Soil was sampled twice per crop season, in Spring and Autumn, in Expriment-1, and in Autumn only in Experiment-2. The results were influenced by spatial and temporal variations that were not always linked to management practices. This two-year study demonstrated that the quantification of SOC and SOM were poor predictors of change in management practices over the timeframe of the study, but that microbial biomass responded quickly to the incorporation of FYM. SOC and SOM were affected by soil texture, but not significantly by inputs, and were associated with extractable Ca2+ and total-N. This study demonstrates that diachronic studies increase our understanding of SOC, SOM, MBC and MBN dynamics and the impacts of short-term change in soil management practices. Furthermore, spatial variation within one field was found to lead to different outcomes and to be a better predictor of response to management.