Determination of areas with the most significant shift in persistence of pests in Europe under climate change

Evaluating invasion risk and population dynamics of the brown marmorated stink bug across the contiguous United States

BACKGROUND

Invasive species threaten the productivity and stability of natural and managed ecosystems. Predicting the spread of invaders, which can aid in early mitigation efforts, is a major challenge, especially in the face of climate change. While ecological niche models are effective tools to assess habitat suitability for invaders, such models have rarely been created for invasive pest species with rapidly expanding ranges. Here, we leveraged a national monitoring effort from 543 sites over 3 years to assess factors mediating the occurrence and abundance of brown marmorated stink bug (BMSB, Halyomorpha halys), an invasive insect pest that has readily established throughout much of the United States.

RESULTS

We used maximum entropy models to estimate the suitable habitat of BMSB under several climate scenarios, and generalized boosted models to assess environmental factors that regulated BMSB abundance. Our models captured BMSB distribution and abundance with high accuracy, and predicted a 70% increase in suitable habitat under future climate scenarios. However, environmental factors that mediated the geographical distribution of BMSB were different from those driving abundance. While BMSB occurrence was most affected by winter precipitation and proximity to populated areas, BMSB abundance was influenced most strongly by evapotranspiration and solar photoperiod.

CONCLUSION

Our results suggest that linking models of establishment (occurrence) and population dynamics (abundance) offers a more effective way to forecast the spread and impact of BMSB and other invasive species than simply occurrence-based models, allowing for targeted mitigation efforts. Implications of distribution shifts under climate change are discussed. © 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

ECORISK2050: An Innovative Training Network for predicting the effects of global change on the emission, fate, effects, and risks of chemicals in aquatic ecosystems

By 2050, the global population is predicted to reach nine billion, with almost three quarters living in cities. The road to 2050 will be marked by changes in land use, climate, and the management of water and food across the world. These global changes (GCs) will likely affect the emissions, transport, and fate of chemicals, and thus the exposure of the natural environment to chemicals. ECORISK2050 is a Marie Skłodowska-Curie Innovative Training Network that brings together an interdisciplinary consortium of academic, industry and governmental partners to deliver a new generation of scientists, with the skills required to study and manage the effects of GCs on chemical risks to the aquatic environment. The research and training goals are to: (1) assess how inputs and behaviour of chemicals from agriculture and urban environments are affected by different environmental conditions, and how different GC scenarios will drive changes in chemical risks to human and ecosystem health; (2) identify short-to-medium term adaptation and mitigation strategies, to abate unacceptable increases to risks, and (3) develop tools for use by industry and policymakers for the assessment and management of the impacts of GC-related drivers on chemical risks. This project will deliver the next generation of scientists, consultants, and industry and governmental decision-makers who have the knowledge and skillsets required to address the changing pressures associated with chemicals emitted by agricultural and urban activities, on aquatic systems on the path to 2050 and beyond.

Potential distribution of fall armyworm in Africa and beyond, considering climate change and irrigation patterns

The fall armyworm, Spodoptera frugiperda (FAW), first invaded Africa in 2016 and has since become established in many areas across the continent where it poses a serious threat to food and nutrition security. We re-parameterized the existing CLIMEX model to assess the FAW global invasion threat, emphasizing the risk of transient and permanent population establishment in Africa under current and projected future climates, considering irrigation patterns. FAW can establish itself in almost all countries in eastern and central Africa and a large part of western Africa under the current climate. Climatic barriers, such as heat and dry stresses, may limit the spread of FAW to North and South Africa. Future projections suggest that FAW invasive range will retract from both northern and southern regions towards the equator. However, a large area in eastern and central Africa is projected to have an optimal climate for FAW persistence. These areas will serve as FAW 'hotspots' from where it may migrate to the north and south during favorable seasons and then pose an economic threat. Our projections can be used to identify countries at risk for permanent and transient FAW-population establishment and inform timely integrated pest management interventions under present and future climate in Africa.

Non-linear physiological responses to climate change: the case of Ceratitis capitata distribution and abundance in Europe

Understanding how climate change might influence the distribution and abundance of crop pests is fundamental for the development and the implementation of pest management strategies. Here we present and apply a modelling framework assessing the non-linear physiological responses of the life-history strategies of the Mediterranean fruit fly (Ceratitis capitata, Wiedemann) to temperature. The model is used to explore how climate change might influence the distribution and abundance of this pest in Europe. We estimated the change in the distribution, abundance and activity of this species under current (year 2020) and future (years 2030 and 2050) climatic scenarios. The effects of climate change on the distribution, abundance and activity of C. capitata are heterogeneous both in time and in space. A northward expansion of the species, an increase in the altitudinal limit marking the presence of the species, and an overall increase in population abundance is expected in areas that might become more suitable under a changing climate. On the contrary, stable or reduced population abundances can be expected in areas where climate change leads to equally suitable or less suitable conditions. This heterogeneity reflects the contribution of both spatial variability in the predicted climatic patterns and non-linearity in the responses of the species’ life-history strategies to temperature.

Insights in genetic diversity of German and Italian grape berry moth (Eupoecilia ambiguella) populations using novel microsatellite markers

The grape berry moth Eupoecilia ambiguella (Lepidoptera: Tortricidae) is causing significant damage to grape berries, however, little is known on population genetics of this lepidopteran pest insect, hindered so far by the lack of suitable molecular markers. Here we report on the development of ten microsatellite markers of which six were used to characterise 21 E. ambiguella populations obtained from two viticultural regions in Germany and Italy. Moths were sampled during two subsequent generations (flights) in the same vineyard as well as in vineyards surrounded by different landscape types. German and Italian populations were genetically differentiated and a significant isolation by distance was evident. No significant divergence was observed among the populations from first or second flight moths, however, inbreeding was higher in first than in second flight populations. Moreover, inbreeding was influenced by habitat composition and complexity of landscape around vineyards, being positively associated with the percentage of area covered by grapevine. Population genetics of E. ambiguella could thus be affected by the presence of alternative host plants in viticultural landscapes, which is important in the light of both insecticide resistance management and sustainable pest management.

Intraspecific competition counters the effects of elevated and optimal temperatures on phloem-feeding insects in tropical and temperate rice

The direct effects of rising global temperatures on insect herbivores could increase damage to cereal crops. However, the indirect effects of interactions between herbivores and their biotic environment at the same temperatures will potentially counter such direct effects. This study examines the potential for intraspecific competition to dampen the effects of optimal temperatures on fitness (survival × reproduction) of the brown planthopper, Nilaparvata lugens [BPH] and whitebacked planthopper, Sogatella furcifera [WBPH], two phloem-feeders that attack rice in Asia. We conducted a series of experiments with increasing densities of ovipositing females and developing nymphs on tropical and temperate rice varieties at 25, 30 and 35°C. Damage from planthoppers to the tropical variety was greater at 30°C compared to 25°C, despite faster plant growth rates at 30°C. Damage to the temperate variety from WBPH nymphs was greatest at 25°C. BPH nymphs gained greater biomass at 25°C than at 30°C despite faster development at the higher temperature (temperature-size rule); however, the effect was apparent only at high nymph densities. WBPH survival, development rates and nymph weights all declined at ≥ 30°C. At about the optimal temperature for WBPH (25°C), intraspecific crowding reduced nymph weights. Temperature has little effect on oviposition responses to density, and intraspecific competition between females only weakly counters the effects of optimal temperatures on oviposition in both BPH and WBPH. Meanwhile, the deleterious effects of nymph crowding will counter the direct effects of optimal temperatures on voltinism in BPH and on body size in both BPH and WBPH. The negative effects of crowding on BPH nymphs may be decoupled from resource use at higher temperatures.

Temperature-dependent oviposition and nymph performance reveal distinct thermal niches of coexisting planthoppers with similar thresholds for development

The brown planthopper (Nilapavata lugens: BPH) and whitebacked planthopper (Sogatella furcifera: WBPH) co-occur as the principal pests of rice in Asia. A review of previous studies suggests that the two species have similar temperature tolerances and similar temperature thresholds for development. However, the distribution and seasonality of WBPH suggest that its temperature optima for performance (survival, oviposition and growth) may be lower than for BPH. We compared adult longevity, oviposition, nymph survival and development success, as well as nymph biomass in both species across a gradient of constant temperatures from 15°C-40°C, at 5°C intervals. The most suitable temperatures for oviposition, nymph biomass and development success were 5-10°C lower for WBPH than for BPH. Furthermore, compared to BPH, WBPH demonstrated clear differences in oviposition on different rice subspecies and on rice at different growth stages at 25°C and 30°C, but not at other temperatures. The results suggest that aspects of herbivore performance within tolerable temperature ranges, which are not often included in temperature models, may be more useful than thermal tolerances or development thresholds in predicting the effects of global warming on pest damage to crops.

Pest Management and Ochratoxin A Contamination in Grapes: A Review

Ochratoxin A (OTA) is the most toxic member of ochratoxins, a group of toxic secondary metabolites produced by fungi. The most relevant species involved in OTA production in grapes is Aspergillus carbonarius. Berry infection by A. carbonarius is enhanced by damage to the skin caused by abiotic and biotic factors. Insect pests play a major role in European vineyards, and Lepidopteran species such as the European grapevine moth Lobesia botrana are undoubtedly crucial. New scenarios are also emerging due to the introduction and spread of allochthonous pests as well as climate change. Such pests may be involved in the dissemination of OTA producing fungi even if confirmation is still lacking and further studies are needed. An OTA predicting model is available, but it should be integrated with models aimed at forecasting L. botrana phenology and demography in order to improve model reliability.

Leaf beetle decline in Central Europe (Coleoptera: Chrysomelidae s.l.)?*

Based on 168,674 records in the database ChryFaun changes in distribution and abundance of leaf beetles (Chrysomelidae s.l.) in Central Europe were analysed from 1900 through 2009. From the first decade (1900–1909) to the last (2000–2009) the number of records per decade increased by factor 26, from 1513 to 41,269. The number of species increased from 395 in decade 1 to 606 in decade 10, but only 532 were reported in decade 11. The number of species with fewer records increased from 1990 although the total number of records increased continuously. Decrease and increase is found likewise in mono-, oligo-, and polyphagous species. Twenty-two species (3.0%) have not been reported since 1990, and 42 (5.8%) since 2000. 71% of all taxa reported between 2000 and 2009 had fewer records than in the immediately previous decade. These indications of decline correspond with numerous published studies on decline in other groups of arthropods. Analysis shows that data from private and public collections are useful for the retrospective analysis of numbers and distributions of leaf beetles (and other organisms).

Pest management under climate change: The importance of understanding tritrophic relations

Plants and insects depend on climatic factors (temperature, solar radiation, precipitations, relative humidity and CO₂) for their development. Current knowledge suggests that climate change can alter plants and insects development and affect their interactions. Shifts in tritrophic relations are of particular concern for Integrated Pest Management (IPM), because responses at the highest trophic level (natural enemies) are highly sensitive to warmer temperature. It is expected that natural enemies could benefit from better conditions for their development in northern latitudes and IPM could be facilitated by a longer period of overlap. This may not be the case in southern latitudes, where climate could become too warm. Adapting IPM to future climatic conditions requires therefore understanding of changes that occur at the various levels and their linkages. The aim of this review is to assess the current state of knowledge and highlights the gaps in the existing literature concerning how climate change can affect tritrophic relations. Because of the economic importance of wine production, the interactions between grapevine, Vitis vinifera (1st), Lobesia botrana (2nd) and Trichogramma spp., (3rd), an egg parasitoid of Lobesia botrana, are considered as a case study for addressing specific issues. In addition, we discuss models that could be applied in order quantify alterations in the synchrony or asynchrony patterns but also the shifts in the timing and spatial distribution of hosts, pests and their natural enemies.

Life-history traits and physiological limits of the alpine fly Drosophila nigrosparsa (Diptera: Drosophilidae): A comparative study

Interspecific variation in life-history traits and physiological limits can be linked to the environmental conditions species experience, including climatic conditions. As alpine environments are particularly vulnerable under climate change, we focus on the montane-alpine fly Drosophila nigrosparsa. Here, we characterized some of its life-history traits and physiological limits and compared these with those of other drosophilids, namely Drosophila hydei, Drosophila melanogaster, and Drosophila obscura. We assayed oviposition rate, longevity, productivity, development time, larval competitiveness, starvation resistance, and heat and cold tolerance. Compared with the other species assayed, D. nigrosparsa is less fecund, relatively long-living, starvation susceptible, cold adapted, and surprisingly well heat adapted. These life-history characteristics provide insights into invertebrate adaptations to alpine conditions which may evolve under ongoing climate change.

Impact of climate and host availability on future distribution of Colorado potato beetle

Colorado Potato Beetle (CPB) is a devastating invasive pest of potato both in its native North America and now across Eurasia. It also damages eggplant, tomato and feeds on several wild species in the Solanaceae, such as S. eleagnifolium and S. rostratum Dunal (SR). Since first categorized as a pest in 1864, CPB has spread rapidly across North America, Europe and Asia. In light of its invasiveness and economic importance, it is necessary to study how climate change and host availability may alter the distribution of the CPB. Maximum Entropy (MaxEnt) models were used to anticipate global range expansion as influenced by environmental conditions, and by the possibility of cooperative invasion of CPB and its wild host SR. The results indicate that both CPB and SR can occupy warm areas of North America, South Africa, Europe, China, and Australia. Future climate conditions may promote CPB expansion into northern regions and SR into the circumpolar latitudes. The existing range and continued spread of SR may also assist the global expansion of CPB. Future management of this pest should consider the impacts of global climate change and host availability on its potential global distribution.

Mortality of Eggs and Newly Hatched Larvae of Lobesia botrana (Lepidoptera: Tortricidae) Exposed to High Temperatures in the Laboratory

The hypothesis that bunch-zone leaf removal reduces infestations of the European grapevine moth, Lobesia botrana (Denis & Schiffermüller) (Lepidoptera: Tortricidae), by increasing egg and larval mortality owing to sunlight exposure was evaluated in the laboratory by subjecting different egg stages (white, red-eyes, and black-head) and newly hatched larvae to high temperatures. Based on temperatures recorded in a northern Italian vineyard on sun-exposed berries belonging to south-west facing bunches, eggs were subjected to constant temperatures of 40 °C and 37 °C for one or two periods of 3 or 6 h, and to 24-h temperature cycle with peak of 40 °C. Larvae were exposed to 24-h high-temperature cycles with peaks of 35, 37, and 40 °C. The results showed partial egg mortality at 40 °C, increasing with exposure hours and periods, and as eggs matured. Egg mortality was not affected by exposure to 37 °C. Larval survival already decreased significantly at 37 °C and was even lower at 40 °C. These laboratory data are in agreement with the hypothesis that temperatures reached by berries exposed to sunlight cause egg and larval mortality. Data on egg and larval susceptibility to high temperatures have also implications for species distribution and effects of climate change.

Predatory beetles feed more pest beetles at rising temperature

BACKGROUND

Climate warming is a challenge for many plants and animals as they have to respond to rising temperature. Rising temperature was observed to affect herbivores and predators. Activity-density of abundant predatory carabid beetles, which are considered important natural control agents of agricultural pests, was observed to increase at rising temperature. The pollen beetle Meligethes aeneus is one of the most important insect pests in European oilseed rape fields, and its larvae were observed to be important prey to carabid beetles. Therefore, we performed a laboratory experiment to detect whether rising temperature affects the number of pollen beetle larvae killed by five abundant carabids, and larval biomass ingested by carabids. In three climate chambers actual temperature (T1) was compared to temperatures increased by 3 °C (T2) and 5 °C (T3). This is the first study investigating the feeding of carabid predators on an arable pest insect spanning a realistic forecasted climate warming scenario of 3 and 5 °C, thus providing basic knowledge on that neglected research area. We hypothesized that carabids kill more pollen beetle larvae at rising temperature, and biomass intake by carabids increases with rising temperature.

RESULTS

Both beetle species and temperature had significant effects on the number of killed Meligethes larvae and larval biomass ingested by carabids. Amara ovata, Harpalus distinguendus and Poecilus cupreus killed significantly more pollen beetle larvae at T2 and T3 compared to T1. Anchomenus dorsalis killed significantly more larvae at T2 than T1, and Harpalus affinis showed no significant differences among temperatures. Biomass intake by A. ovata, H. distinguendus and A. dorsalis was significantly larger at T2 and T3 compared to T1. Biomass intake by H. affinis and P. cupreus did not significantly differ among temperatures. Among the five carabids tested P. cupreus exhibited the highest values for both number of killed larvae and biomass intake.

CONCLUSIONS

Our lab results suggest a clear potential for higher feeding of pollen beetle larvae by carabid beetles at rising temperature. As rising temperature leads to increased activity of abundant arable carabids in the field, it may be expected that there is enhanced pest suppression under warmer field conditions.

Foliar application of methyl jasmonate induced physio-hormonal changes in Pisum sativum under diverse temperature regimes

Global climate change brings with it unwarranted shifts in both abiotic (heat stress, cold stress, wind, precipitation) and biotic (pathogens, pests) environmental factors, thus posing a threat to agricultural productivity across the world. In plants, lodging due to storms or herbivory causes wounding stress and consequently enhances endogenous jasmonates. In response, the plant growth is arrested as plant defense is prioritized. We pre-treated pea plants with elevated methyl jasmonate (MeJA) levels i.e. 50 μM, 100 μM and 200 μM under controlled growth chamber conditions. The pre-treated plants were then kept at 40 °C (heat stress--HS), 4 °C (cold stress--CS) and 20 °C (optimum/control temperature--OT) for 72 h. The effect of such treatments on plant growth attributes, photosynthesis, stomatal conductance, cell death rate, and regulation of endogenous hormones were observed. Elevated MeJA application hindered plant growth attributes under HS, CS and OT conditions. Moreover, elevated MeJA levels lowered the rate of photosynthesis and stomatal conductance, induced stomatal closure, caused higher cells mortality in leaves under HS, CS, and OT conditions. Endogenous ABA contents significantly declined in all MeJA treatments under HS and OT, but increased under CS conditions. Exogenous MeJA enhanced endogenous jasmonic acid contents of pea plants, but altered endogenous salicylic acid contents under varying temperatures. Current study shows that higher concentrations of exogenous MeJA strengthen plant defense mechanism by hindering plant growth under stress conditions.

A novel set of microsatellite markers for the European Grapevine Moth Lobesia botrana isolated using next-generation sequencing and their utility for genetic characterization of populations from Europe and the Middle East

Using a high-throughput 454 pyrosequencing approach a novel set of microsatellite markers was developed for one of the key grapevine insect pests, the European grapevine moth Lobesia botrana (Lepidoptera: Tortricidae). 20 primer pairs flanking a microsatellite motif were designed based on the sequences obtained and were subsequently evaluated in a sample of 14 L. botrana populations from Europe and the Middle East. 11 markers showed stable and reproducible amplification patterns; however, one of the 11 markers was monomorphic in all L. botrana populations analysed. Estimated frequencies of null alleles of more than 20% were evident for two of the markers tested, but varied substantially depending on the respective L. botrana population. In 12 of the 14 L. botrana populations observed heterozygosities were lower to those expected under Hardy-Weinberg equilibrium, indicating a deficiency of heterozygotes in the respective populations. The overall F ST value of 0.075 suggested a moderate but significant genetic differentiation between the L. botrana populations included in this study. In addition, a clear geographic structure was detected in the set of samples, evident through a significant isolation by distance and through results from structure analysis. In structure analysis, L. botrana populations were grouped in two clearly separated clusters according to their European (Spain, Italy, Germany) or Middle Eastern (Israel, Syria, Turkey) origin. This novel set of microsatellite markers can now be applied to study the evolutionary ecology of this species including host shifts and host adaptation as well as spread of individuals across worldwide viticulture.

Range-expanding pests and pathogens in a warming world

Crop pests and pathogens (CPPs) present a growing threat to food security and ecosystem management. The interactions between plants and their natural enemies are influenced by environmental conditions and thus global warming and climate change could affect CPP ranges and impact. Observations of changing CPP distributions over the twentieth century suggest that growing agricultural production and trade have been most important in disseminating CPPs, but there is some evidence for a latitudinal bias in range shifts that indicates a global warming signal. Species distribution models using climatic variables as drivers suggest that ranges will shift latitudinally in the future. The rapid spread of the Colorado potato beetle across Eurasia illustrates the importance of evolutionary adaptation, host distribution, and migration patterns in affecting the predictions of climate-based species distribution models. Understanding species range shifts in the framework of ecological niche theory may help to direct future research needs.

Differential expression of superoxide dismutase genes in aphid-stressed maize (Zea mays L.) seedlings

The aim of this study was to compare the expression patterns of superoxide dismutase genes (sod2, sod3.4, sod9 and sodB) in seedling leaves of the Zea mays L. Tasty Sweet (susceptible) and Ambrozja (relatively resistant) cultivars infested with one of two hemipteran species, namely monophagous Sitobion avenae F. (grain aphid) or oligophagous Rhopalosiphum padi L. (bird cherry-oat aphid). Secondarily, aphid-elicited alternations in the antioxidative capacity towards DPPH (1,1-diphenyl-2-picrylhydrazyl) radical in insect-stressed plants were evaluated. Comprehensive comparison of expression profiles of the four sod genes showed that both insect species evoked significant upregulation of three genes sod2, sod3.4 and sod9). However, aphid infestation affected non-significant fluctuations in expression of sodB gene in seedlings of both maize genotypes. The highest levels of transcript accumulation occurred at 8 h (sod2 and sod3.4) or 24 h (sod9) post-infestation, and aphid-induced changes in the expression of sod genes were more dramatic in the Ambrozja cultivar than in the Tasty Sweet variety. Furthermore, bird cherry-oat aphid colonization had a more substantial impact on levels of DPPH radical scavenging activity in infested host seedlings than grain aphid colonization. Additionally, Ambrozja plants infested by either hemipteran species showed markedly lower antioxidative capacity compared with attacked Tasty Sweet plants.