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Summary: Brown planthopper (BPH, Nilaparvata lugens), a highly destructive insect pest, poses a serious threat to rice (Oryza sativa) production worldwide. Jasmonates are key phytohormones that regulate plant defences against BPH; however, the molecular link between jasmonates and BPH responses in rice remains largely unknown. Here, we discovered a Poaceae‐specific metabolite, mixed‐linkage β‐1,3;1,4‐d‐glucan (MLG), which contributes to jasmonate‐mediated BPH resistance. MLG levels in rice significantly increased upon BPH attack. Overexpressing OsCslF6, which encodes a glucan synthase that catalyses MLG biosynthesis, significantly enhanced BPH resistance and cell wall thickness in vascular bundles, whereas knockout of OsCslF6 reduced BPH resistance and vascular wall thickness. OsMYC2, a master transcription factor of jasmonate signalling, directly controlled the upregulation of OsCslF6 in response to BPH feeding. The AT‐rich domain of the OsCslF6 promoter varies in rice varieties from different locations and natural variants in this domain were associated with BPH resistance. MLG‐derived oligosaccharides bound to the plasma membrane‐anchored LECTIN RECEPTOR KINASE1 OsLecRK1 and modulated its activity. Thus, our findings suggest that the OsMYC2‐OsCslF6 module regulates pest resistance by modulating MLG production to enhance vascular wall thickness and OsLecRK1‐mediated defence signalling during rice‐BPH interactions. [ABSTRACT FROM AUTHOR]

Aim: Tree pests have major impacts in both natural and agricultural systems. Despite their ecological and economic importance, it is likely that pests go unreported in many regions. Using a global dataset of tree pests and multiple metrics of pest diversity standardized for host availability, we describe the biogeography of under‐reporting and reveal potential for future pest invasions. Location: Global. Time period: Contemporary. Major taxa studied: Pathogens, insect pests and native tree hosts. Methods: We assembled the global distributions of 3,828 tree pests and 2,689 host tree species across 226 countries, and calculated two metrics of pest diversity that account for host availability: pest saturation (i.e., the proportion of the known pests of native host trees present with countries) and pest deficit (the number of known pests of native trees that have not yet been reported in countries). We used Bayesian regression models to identify how sampling, socio‐economic variables, climate and ecological drivers affect estimates of pest saturation and deficit. Results: We show that most countries are reported to have fewer than 50% of the pests for which native hosts are available—corresponding to hundreds of additional pest species per country. Pest saturation was lowest in Africa and central Asia, while pest deficit was highest in eastern Europe. Accounting for research output, pest saturation was higher in warmer and wetter countries, while pest deficit was highest in countries with greater host phylogenetic diversity. Low saturation and high deficit even in well‐documented countries suggest a considerable potential for pest range expansion if barriers to dispersal are lowered. Main conclusions Our findings indicate that, although all countries could potentially host additional pests, countries with low research output and high host diversity should be prioritized for future pest discovery and surveillance to ensure timely detection and implementation of pest mitigation strategies. [ABSTRACT FROM AUTHOR]

• Original dynamic model of plant-pest interactions with host age-dependent infection. • Application to a major pest, the coffee berry borer. • Well-posedness of the nonlinear PDE system using semigroup theory. • Asymptotic analysis and computation of the basic reproduction number. Coffee production is an important agriculture activity which contributes significantly to the economic growth of many countries in the world. One of the major constraints to coffee production throughout the world is the damage caused by the coffee berry borer (CBB), Hypothenemus hampei (Coleoptera: Scolytidae). It is the most damaging insect pest to coffee production in the world. These insects infest coffee berries, preferably mature berries, and spend most of their life cycle inside the berries, which make them quite difficult to control. In this work, we introduce and analyse a berry age-structured model describing the infestation dynamics of coffee berries by CBB. Using the semigroup theory in the case of Lipschitz perturbation, we show that the model has a unique nonnegative and bounded solution. We derive an explicit formula of the basic reproduction number, R 0 , using the next generation approach and the biological interpretation of this threshold in a specific case. Numerical simulations are carried out to illustrate the theoretical results. [ABSTRACT FROM AUTHOR]

Coffee berry borer Hypothenemus hampei (Coleoptera: Scolytidae), denoted CBB, is the most important insect pest of coffee worldwide, with a high impact on the economy of coffee producing countries. The insect spends a great part of its life cycle inside the coffee berry and causes severe crop losses. Biological control based on the use of an entomopathogenic fungus is a major alternative to chemical pesticides in order to control CBB. The fungus is sprayed on the coffee berries to kill CBB when the insects drill holes to penetrate inside the berries. Our aim in this work is to optimise the fungus application, using a modelling approach. We first formulate a mathematical model describing the infestation dynamics of coffee berries by CBB. We analyse the model and show that the stability of the pest‐free and coexistence equilibria depends on the basic reproduction number. To introduce a control variable corresponding to the application of an entomopathogenic fungus, we then extend the model and include the fungus dynamics. We formulate an optimal problem which consists in maximising the coffee yield, while minimising the control cost, as well as the CBB population for the next cropping season. The existence of the optimal control and the necessary optimality condition are established using Pontryagin's Maximum Principle. The optimal control problem is solved numerically using the BOCOP software and simulations are provided, showing that the use of entomopathogenic fungus effectively controls CBB. [ABSTRACT FROM AUTHOR]

Tomato is more prone to Tuta absoluta invasion and damages as compared to other host plants but the mechanism behind this preference has not been elucidated. Here, two contrasting host preference plants, tomato and eggplant, were used to investigate biochemical and transcriptomic modifications induced by T. absoluta infestation. Biochemical analysis at 0–72 h post T. absoluta infestation revealed significantly reduced concentrations of amino acid, fructose, sucrose, jasmonic acid, salicylic acid, and total phenols in tomato compared to eggplant, mainly at 48 h post T. absoluta infestation. Transcriptome analysis showed higher transcript changes in infested eggplant than tomato. Signaling genes had significant contributions to mediate plant immunity against T. absoluta , specifically genes associated with salicylic acid in eggplant. Genes from PR1b1 , NPR1 , NPR3 , MAPKs , and ANP1 families play important roles to mitigate T. absoluta infestation. Our results will facilitate the development of control strategies against T. absoluta for sustainable tomato production. • Tomato is more prone to Tuta absoluta invasion than eggplant. • Signaling genes highly contribute to plant immunity against T. absoluta. • Strong regulation of hormones, amino acids, sugars, total phenols in eggplant improve its resistance. [ABSTRACT FROM AUTHOR]

Traditional methods of quantifying the harmful effects of invertebrates on plants require time-consuming identification of large numbers of individuals at species level. Collected specimens usually are killed; this may be unacceptable for some strictly protected species and may bias the results of subsequent surveys at the same site. We developed a “harmfulness scale” for quick, non-invasive assessment of invertebrate impacts on plants, and used the scale to test differences in invertebrate attack on species ofBalsaminaceae,PolygonaceaeandAsteraceaegrowing in lowland and mountains in Poland. In 2010–2011, we recorded 9190 invertebrates and identified themin situto family or superfamily level. Among them were 7593 pests, accounting for 82.6% of all recorded organisms. Pests were three times more numerous in the mountains than in the lowland.Balsaminaceaewere most heavily attacked by pests (92.9% of all organisms detected on them).Aphidoideaewere the most numerous pests. This method can help reduce the costs and labour required for this type of research, facilitating progress in theoretical biology and in the development of practical phytosanitary measures. [ABSTRACT FROM AUTHOR]

Understanding the plant-pest interaction under warming with grazing conditions is critical to predict the response of alpine meadow to future climate change. We investigated the effects of experimental warming and grazing on the interaction between plants and the grassland caterpillar Gynaephora menyuanensis in an alpine meadow on the Tibetan Plateau in 2010 and 2011. Our results showed that grazing significantly increased nitrogen concentration in graminoids and sward openness with a lower sward height, sward coverage, and plant litter mass in the community. Grazing significantly increased G. menyuanensis body size and potential fecundity in 2010. The increases in female body size were about twofold greater than in males. In addition, grazing significantly increased G. menyuanensis density and its negative effects on aboveground biomass and graminoid coverage in 2011. We found that G. menyuanensis body size was significantly positively correlated with nitrogen concentration in graminoids but negatively correlated with plant litter mass. Even though warming did not significantly increased G. menyuanensis performance and the negative effects of G. menyuanensis on alpine meadow, the increases in G. menyuanensis growth rate and its negative effect on aboveground biomass under the warming with grazing treatment were significantly higher than those under the no warming with grazing treatment. The positive effects of grazing on G. menyuanensis performance and its damage were exacerbated by the warming treatment. Our results suggest that the fitness of G. menyuanensis would increase under future warming with grazing conditions, thereby posing a greater risk to alpine meadow and livestock production. [ABSTRACT FROM AUTHOR]

Plants have developed a complex defense system against diverse pests and pathogens. Once pathogens overcome mechanical barriers to infection, plant receptors initiate signaling pathways driving the expression of defense response genes. Plant immune systems rely on their ability to recognize enemy molecules, carry out signal transduction, and respond defensively through pathways involving many genes and their products. Pathogens actively attempt to evade and interfere with response pathways, selecting for a decentralized, multicomponent immune system. Recent advances in molecular techniques have greatly expanded our understanding of plant immunity, largely driven by potential application to agricultural systems. Here, we review the major plant immune system components, state of the art knowledge, and future direction of research on plant–pathogen interactions. In our review, we will discuss how the decentralization of plant immune systems have provided both increased evolutionary opportunity for pathogen resistance, as well as additional mechanisms for pathogen inhibition of such defense responses. We conclude that the rapid advances in bioinformatics and molecular biology are driving an explosion of information that will advance agricultural production and illustrate how complex molecular interactions evolve. [ABSTRACT FROM AUTHOR]