Fungal lectins, with their specific glycan-binding activity, represent promising biopesticide candidates. This study investigates the potential of six fungal lectins to control Colorado potato beetle (CPB) larvae (Leptinotarsa decemlineata). In vitro feeding trials with recombinant lectins were performed to evaluate their individual toxicity. Marasmius oreades agglutinin (MOA) caused significantly higher mortality than the other lectins, whereas Coprinopsis cinerea lectin 2 (CCL2) and Aleuria aurantia lectin (AAL) completely inhibited weight gain. Functional analysis of MOA mutants revealed that both carbohydrate-binding and proteolytic domains are essential for toxicity. MOA binds to midgut glycoproteins in CPB larvae, disrupting midgut epithelium. Histology and ultramicroscopy showed that MOA causes loss of apicobasal polarity and detachment of basal lamina. No acute toxicity of lectins against adult European honeybees (Apis mellifera) was found; however, significant sublethal effects on larval development were observed. MOA shows promise as a selective bioinsecticide for sustainable CPB control with minimal nontarget effects.

Strawberry plants are attacked by various arthropod herbivores, including insects and mites, causing damage to different parts of the plants during the season. Strawberry plantations also harbour beneficial arthropods such as predators, parasitoids and pollinators (e.g., predatory mites, lacewings, hoverflies,). Applications of beneficial fungi may enhance plant growth and decrease the incidence of specific arthropod pests, but their impact on entire arthropod communities is largely unknown. Two-season field trials were conducted in Denmark and Slovenia to study effects of the entomopathogenic Metarhizium brunneum, the mycoparasitic Clonostachys rosea, and arbuscular mycorrhizal biofertilizers, all fungi, on the main pest and beneficial arthropods in integrated (IPM) and organic (ORG) strawberry production systems. Soildeployed bioinocula had limited impact on aboveground arthropod assemblages, but treatment with the M. brunneum bioinoculum significantly increased the number of predators in the trials in Slovenia, while reducing arthropod abundance and diversity in Denmark. Agricultural management strongly affected arthropod communities, with ORG trials harbouring higher arthropod abundance and diversity compared to IPM, suggesting potential benefits of sustainable farming practices. The nuanced relationships among herbivores, beneficials, and pest infestations invites further investigation to unravel the underlying ecological mechanisms shaping pest dynamics in diverse agricultural landscapes.

This study investigated the behavioural responses of two wireworm species to three selected treatments: compost teas (16 and 19), synthetic 3-octanone, and Metarhizium brunneum (strain 1868). Behavioural assays were conducted under controlled conditions using rhizotrons and olfactometers. Results showed that compost tea 16 acted as an attractant, compost tea 19 had no significant effect, while both 3-octanone and M. brunneum exhibited consistent repellence in both species. These responses were consistent across experimental systems, indicating robust behavioural patterns. The findings suggest that wireworm behaviour is influenced by chemically mediated belowground cues, with contrasting responses depending on cue origin. These results highlight the potential of these treatments as alternatives for sustainable pest management, including push-pull approaches. Further field validation is required to confirm their effectiveness under practical conditions.

Plodova vinska mušica (Drosophila suzukii) sodi med invazivne tujerodne vrste z izrazitim gospodarskim pomenom, saj povzroča škodo v sadjarstvu in vinogradništvu. Izgube pridelka nastajajo zaradi odlaganja jajčec v zrele in še zoreče plodove, s katerimi se ličinke hranijo. Pri tem nastanejo mehanske poškodbe, ki povečujejo tveganje za pojav sekundarnih okužb. Vrsta izbira mesta za hranjenje in odlaganje jajčec na podlagi hlapnih spojin, ki jih na površini sadja proizvajajo kvasovke. V naših vinogradih je najštevilčnejša vrsta Hanseniaspora uvarum, a jo v zadnjih letih, predvsem na Primorskem, zamenjuje termotolerantna tujerodna vrsta Hanseniaspora opuntiae, ki kaže velik potencial za razširjanje. Na podlagi dosedanjih raziskav je vrsta D. suzukii pogosto kazala preferenco do kvasovk H. uvarum in "kontrolne vrste" Saccharomyces cerevisiae. V tej raziskavi nas je zato zanimalo, kako se bodo osebki D. suzukii odzvali, oziroma kakšna je njihova preferenca pri hranjenju in odlaganju jajčec med tremi testiranimi vrstami kvasovk. Vedenjska poskusa smo ovrednotili z uporabo preferenčnega indeksa, pri čemer so osebki D. suzukii izkazali statistično značilno najvišjo preferenco do kvasovke S. cerevisiae. Pri poskusih pristajanja so osebki D. suzukii značilno pogosteje izbirali H. uvarum kot H. opuntiae, medtem ko pri poskusih odlaganja jajčec med obema vrstama iz rodu Hanseniaspora ni bilo značilnih razlik.

Background: Self-organizing maps (SOMs) are a class of neural network algorithms able to visually describe a high-dimensional dataset onto a two-dimensional grid. SOMs were explored to classify soils based on an array of physical, chemical, and biological parameters. Methods: The SOM analysis was performed considering soil physical, chemical, and microbial data gathered from an array of apple orchards and strawberry plantations managed by organic or conventional methods and located in different European climatic zones. Results: The SOM analysis considering the “climatic zone” categorical variables was able to discriminate the samples from the three zones for both crops. The zones were associated with different soil textures and chemical characteristics, and for both crops, the Continental zone was associated with microbial parameters—including biodiversity indices derived from the NGS data analysis. However, the SOM analysis based on the “management method” categorical variables was not able to discriminate the soils between organic and integrated management. Conclusions: This study allowed for the discrimination of soils of medium- and long-term fruit crops based on their pedo-climatic characteristics and associating these characteristics to some indicators of the soil biome, pointing to the possibility of better understanding the interactions among diverse variables, which could support unraveling the intricate web of relationships that define soil quality.

The Japanese beetle, Popillia japonica Newman (Coleoptera, Scarabaeoidea), listed by the European Commission as one of the 20 priority plant pests, is reported for the first time in Slovenia. In the summer of 2024, eight beetles were found in funnel traps at two motorway service stations in central Slovenia: Lukovica South and Barje South. Visual inspections in the surrounding area revealed no infestation or damage to susceptible host plants. In addition to morphological identification, we confirmed the presence of P. japonica through molecular barcoding using the cytochrome c oxidase I (COI) gene. Based on its distribution in neighbouring northern Italy, the nearby outbreak and the isolated findings near the Slovenian border as well as the heavy freight traffic between northern Italy and Slovenia, a passive transport of P. japonica as a hitchhiker is very likely.

Short-term modified-atmosphere storage with an adjusted CO2 and/or O2 concentration could recover blueberry fruit infested with the larvae of quarantine pests. However, this could significantly affect the fruit quality. In our experiment we investigated the performance of highbush blueberry ‘Bluecrop’ fruit (firmness, peel color, individual phenolics, sugars, and organic acids) under four short-term storage regimes: (1) a regular atmosphere with 0.03% CO2, 21% O2, and 78% N2 at 22 °C, i.e., the control; (2) a regular atmosphere with 0.03% CO2, 21% O2, and 78% N2 at 2 °C; (3) a modified atmosphere with 10% CO2, 5% O2, and 85% N2 at 2 °C; and (4) a modified atmosphere with 100% CO2 at 2 °C. Fruit sampling took place after 24 h, 48 h, and 72 h. Fruit firmness was not significantly altered by storage regime or duration, while some significant, but minor, changes were detected in the color parameters. Regarding the primary metabolites, the sugar/organic acid ratio stagnated in the first 48 h in all storage regimes. The content of the majority of the individual phenolics was significantly higher in the fruit stored under control conditions. From our results, we can conclude that the short-term storage of highbush blueberry ‘Bluecrop’ fruit for 24 h in a cold atmosphere does not affect the phenolic content, and storage for 48 h does not affect the total sugar/organic acid ratio, regardless of the atmosphere composition.

Summary Protein complexes from edible oyster mushrooms ( Pleurotus sp.) composed of pleurotolysin A2 (PlyA2) and pleurotolysin B (PlyB) exert toxicity in feeding tests against Colorado potato beetle (CPB) larvae, acting through the interaction with insect‐specific membrane sphingolipid. Here we present a new strategy for crop protection, based on in planta production of PlyA2/PlyB protein complexes, and we exemplify this strategy in construction of transgenic potato plants of cv Désirée. The transgenics in which PlyA2 was directed to the vacuole and PlyB to the endoplasmic reticulum are effectively protected from infestation by CPB larvae without impacting plant performance. These transgenic plants showed a pronounced effect on larval feeding rate, the larvae feeding on transgenic plants being on average five to six folds lighter than larvae feeding on controls. Further, only a fraction (11%–37%) of the larvae that fed on transgenic potato plants completed their life cycle and developed into adult beetles. Moreover, gene expression analysis of CPB larvae exposed to PlyA2/PlyB complexes revealed the response indicative of a general stress status of larvae and no evidence of possibility of developing resistance due to the functional inactivation of PlyA2/PlyB sphingolipid receptors.

The invasive pest, spotted wing drosophila (Drosophila suzukii (Matsumura, 1931) or SWD), damages various soft-skinned fruits, severely impacting orchards and vineyards economically. Current sorting practices in commercial production may overlook early-stage SWD infestations, as visible signs take a few days to appear. Our study focused on managing SWD infesting fruits (blueberry, cherry, and raspberry) without visible signs using an artificial atmosphere with elevated CO2 and low temperature. We hypothesized that these factors affect SWD survival and possibly interact, with potential variations among different soft- or stone-fruit species or varieties. High CO2 concentrations and cold storage both negatively affected SWD development. A 24-h 100% CO2 fumigation, without cold storage, significantly reduced SWD infestations in all 3 fruit species studied. On the other hand, 10% CO2 without cold storage did not cause a significant infestation reduction in cherries. Cold storage alone was too slow to be considered effective. Concurrent low-temperature treatment and CO2 treatment reduced the insecticidal efficacy of CO2 fumigation. Optimal fruit sanitation was achieved with a 3-h 100% CO2 treatment at ambient temperature before cold storage. Raspberries were the most suitable host for SWD development, with over a 5-fold higher SWD development compared to blueberries and over 50 times more than in cherries. We discussed the observed interactions between CO2 fumigation and chilling and suggested a simple postharvest SWD management protocol using optimal CO2 levels, exposure times, and chilling periods-achievable without complex equipment.

The objective of our research was to test hyperspectral imaging as a method for early detection and discrimination of biotic and abiotic stress in maize. We investigated the individual and combined effects of wireworm feeding and drought stress on leaf spectral responses and on various morphological and physiological traits of maize plants, selecting two hybrids with different tolerance to drought. Physiological parameters were determined at three time points (14, 21 and 28 days after adding wireworms and changing watering regime), along with hyperspectral imaging. Most of the differences in physiological characteristics between treatments were detected on day 21, when drought was the main cause of the negative physiological outcome, while the presence of wireworms only caused lower relative chlorophyll content, resulting in lower combined stress damage in some treatments. The morphological data showed greater wireworm damage to hybrid ZP341 and a greater negative effect of combined stress on hybrid FuturiXX. Hyperspectral imaging detected pest infestation and drought stress before they were detected by classical methods, with the highest overall accuracy on day 14 (84.7%) and the lowest on day 28 (67%). It can therefore be used as a method for early detection of wireworm infestation and/or drought in maize.

An aegerolysin protein ostreolysin A6 (OlyA6) binds to cholesterol-complexed sphingomyelin and can be used for specific labelling of lipid rafts. In addition, OlyA6 interacts with even higher affinity with ceramide phosphoethanolamine (CPE), a sphingolipid that dominates in invertebrate cell membranes. In the presence of pleurotolysin B, a protein bearing the membrane-attack complex/perforin domain, OlyA6 forms pores in insect midgut cell membranes and acts as a potent bioinsecticide. It has been shown that a point mutation of glutamate 69 to alanine (E69A) allows OlyA6 to bind to cholesterol-free sphingomyelin. Using artificial lipid membranes and mammalian MDCK cells, we show that this mutation significantly enhances the interaction of OlyA6 with sphingomyelin and CPE, and allows recognition of these sphingolipids even in the absence of cholesterol. Our results suggest that OlyA6 mutant E69A could serve as complementary tool to detect and study cholesterol-associated and free sphingomyelin or CPE in membranes. However, the mutation does not improve the membrane-permeabilizing activity after addition of pleurotolysin B, which was confirmed in toxicity tests on insect and mammalian cell lines, and on Colorado potato beetle larvae.

Entomopathogenic fungi (EPF) represent promising control agents against wireworms but success in field experiments is inconsistent. The physiological condition of the targeted insect is crucial for its ability to withstand fungal infection. In particular, nutritional status is among the most important determinants of the insects' immune defense. In this study, we investigated the effects of diet on the development of the wireworm Agriotes obscurus (L.) (Coleoptera: Elateridae) and its subsequent susceptibility to the fungal pathogen Metarhizium brunneum (Petch) (Hypocreales: Clavicipitaceae) in a pot experiment. After being reared on one of five plant diets for eight weeks, wireworms were exposed to an environment inoculated with the EPF and monitored for their susceptibility to fungal infection. We then performed a field experiment in which three plant diets (clover, radish, and a cover crop mix), selected according to the insects' performance in the laboratory experiment, were grown as a cover crop with EPF application. Plant diet influenced growth and development of larvae, but there were no strong differences in susceptibility toward fungal infection in the laboratory experiment. Damage levels in EPF-treated plots in the field varied depending on the cover crop. Damage was highest in plots planted with a mix of cover crop species, whereas damage was lowest in plots with clover or radish alone. This agrees with the laboratory results where insect performance was inferior when fed on clover or radish. Cover crop effects on wireworm damage in the subsequent cash crop may thus vary depending on the cover crop species selected.

Plant diversity has the potential to conserve beneficials and thereby naturally controlling arthropod pests. Beneficials’ activity can be increased by pollen-rich plant species. Here we aimed to develop innovative viticultural systems that naturally control arthropod pests, by increasing plant diversity within vineyards planting of selected cover crops. The experimental vineyards were set-up in Chablis (France), Piacenza (Italy), Murfatlar (Romania), Manče (Slovenia), Valencia (Spain) and Nyon (Switzerland). Each vineyard was divided in a traditional and innovative subplot and monitored in 2019 and 2020. The effect of cover crops on arthropods was assessed according to a common protocol using visual samplings and specific traps. Analysing the obtained data, there were no statistically significant differences in the abundance of sampled arthropod pests in the innovative and the traditional systems. Yet, two of five studied pest species tended to be less abundant in the innovative systems. Regarding arthropod beneficials, flying parasitoids and bees tended to benefit from the planting of cover crops in the innovative compared to the traditional systems. Alike, predators such as spiders and carabids were more abundant in vineyards with understorey vegetation. Overall, the arthropod biodiversity seems to benefit from the planting of cover crops but without necessarily favouring pest suppression.

Scarab beetles (Coleoptera: Scarabaeidae) are a cosmopolitan group of beetles found on all continents except Antarctica. Because of their size, vibrant colors, and above all their role in the ecosystem, they are one of the most recognizable and studied taxons of beetles. Most larvae and adult beetles of species belonging to subfamilies Melolonthinae, Rutelinae, Dynastinae and Cetoniinae feed on plant organs such as roots, leaves, flowers and young fruits and are thus considered to be species of economic importance. In this article we describe some of the most economically important species of scarabs, including their most common host plants. Because the use of chemical insecticides to control scarabs is often limited, the implementation of entomopathogenic fungi as biological control agents is an appropriate alternative based on the rational use of microorganisms to maintain an environmentally balanced level of the pest population. Representatives of the genera Beauveria and Metarhizium are the most commonly used entomopathogenic fungi to control larvae (white grubs) of scarab beetles. Biological control by entomopathogenic fungi has shown to be effective in some cases, however host range is often species-specific. Therefore, in order to effectively use the entomopathogens against scarab beetles, one needs to identify target species in grub-infested area and consequently select strains that are capable of overcoming the host’s defences.

In recent decades, the spotted wing Drosophila (SWD) ( Drosophila suzukii ), an invasive pest, has caused a great deal of damage to fruit crops. There is therefore an urgent need to develop strategies to control the populations of this species. It has been found that the landscape context can buffer or increase the severity of pest outbreaks in agriculture, and it is important to understand how this process works in SWD for all crops. Given this background, we investigated the influence of forest on SWD populations in raspberry orchards and surrounding agricultural land. We selected 10 locations in the central part of Slovenia, five of which were closer than 200 m from the forest edge and five of which were more than 200 m from the forest edge. We collected SWD adults in three habitat types per location from the end of June until the end of October 2020. The results showed that forest harboured a larger SWD population than orchards and agricultural land. Over the season, the number of individuals increased exponentially over time, and the difference between forest and other habitat types increased. The distance from the forest had a negative effect on the abundance of SWD. There was a difference in abundance observed between males and females, with males being less abundant farther away from the forest than females. However, the distance from the forest only had a negative effect on the abundance of females in September. Based on the results, we propose potential measures for the control of SWD in raspberry orchards.

Raw data related to Figures 1 to 5 and Table 1 plus suplementary raw data of the publication Razinger et al. (2020) Frontiers in Plant Science 11:535005; doi: 10.3389/fpls.2020.535005.

Microbial inoculants can be an efficient tool to manage the soil and plant microbiomes providing direct beneficial effects, and for modulating native soil and plant-associated microbiota. However, the application of soil microbial inoculants as biofertilizers and biopesticides in agriculture is still limited by factors related to their formulation, application method, and the knowledge about the impact and interactions between microbial inoculants and native soil and plant host microbiomes. The review is thus describing and discussing three major aspects related to microbial-based product exploitation, namely: i) the discovery and screening of beneficial microbial strains; ii) the opportunities and challenges associated with strain multifunctional features; iii) the fermentation and formulation strategies also based on the use of wastes as growth substrates and the technical and regulatory challenges faced in their path to field application. All these issues are addressed in activities performed by the EXCALIBUR project (www.excaliburproject.eu), which aims to expand the current concept about microbiomes interactions, acknowledging their interactive network that can impact agricultural practices as well as on all living organisms within an ecosystem.