Effects of landscape variables and weather conditions on the seasonal arrival and population abundance of the green peach aphid Myzus persicae in sugar beet

Simple SummaryThe green peach aphid (Myzus persicae (Sulzer)) is considered one of the main pests of economically valuable crops. In the last decades, it has developed resistance to several chemical pesticides. More effective and environmentally friendly solutions for green peach aphid management, including plant essential oils, are being tested as alternatives to chemical pesticides. Repellents have gained interest because lower doses can be used against agricultural pests, with a reduced risk of developing insect resistance. In this study, three different types of caraway (Carum carvi L.) seed essential oils against green peach aphids were tested. Repellent activity testing was carried out using a bridge method and host plants of white cabbage. The aphids were placed on the bridge, and their choice was recorded depending on whether they went to the treatment side (containing the selected essential oil) or the control side (no essential oil). All the selected caraway essential oils showed that they repel aphids to various degrees. The optimal essential oil dose was determined in the same way. In addition, the essential oil was mixed with different surfactants to create a formulation basis for ready-to-use products, but the testing showed decreased repellent activity of such mixtures.An in vivo dual choice bioassay with white cabbage as a host plant was used to determine the repellent effect of three different accessions of caraway (Carum carvi L.) essential oils (EOs) against the green peach aphid Myzus persicae (Sulzer). The dominant components of the EO were D-Carvone (47.3–74.4%) and D-limonene (25.2–51.9%), which accounted for 99.2–99.5% of the EOs determined by GC/MS. The EO with the highest D-limonene content (51.9%) showed the highest repellence (Repellency Index (RI) = +41%), which was stable up to 330 min. The incorporation of several surfactants with different hydrophilic-lipophilic balance values (from 12.4 to 16.7) with caraway EO caused a general inhibition of the repellent effect during the testing period (RI from +41% to −19%). Overall, the findings indicate that caraway EO could be used as a green peach aphid repellent, but more work is needed to formulate the EO into a ready-to-use product.

Potato virus Y (PVY) is a destructive and widespread virus in a number of important crops, including potato. Aphid vectors spread this viral infection between plants in a non-persistent manner, and the green peach aphid (Myzus persicae) is the most efficient known vector. In this research, we investigated five cuticle proteins (CuPs) which are expected to be involved in virus transmission at the stylet of aphids. In an RNA interference (RNAi) gene-silencing assay with the green peach aphids (M. persicae), we evaluated the impact of these CuPs on the transmission of PVY with potato and tobacco plants. Using an oral RNAi bioassay where the aphids pierce-suck in an artificial diet that was supplemented with gene-specific dsRNA, the expression of only two CuPs, mpcp2 (DQ108935) and mpcp1 (AF435075.1), could be decreased by 63 and 75%, respectively. Expression of the other three CuPs could not be affected. Subsequently, we investigated what the effect is of the RNAi-mediated gene silencing on the transmission of PVY from potato to tobacco plants. These results showed with a high certainty of 99.5%, for the first time in vivo, a significant involvement of MPCP2 with a reduction of 47% (compared to the dsGFP control) in the transmission of PVY. For MPCP1, the effect was smaller with a reduction of 19% and lower certainty of 86%.

Sugar beet (Beta vulgaris ssp. vulgaris), a key crop for sugar production, faces significant yield losses caused by the black bean aphid Aphis fabae (Scop.) and the green peach aphid Myzus persicae (Sulzer), which also transmits viruses. The restriction on neonicotinoid usage in Europe has intensified this problem, emphasizing the urgent need for breeding resistant crop varieties. This study evaluated 26 sugar beet germplasms for resistance against both aphid species by using performance and feeding behavior assays. Additionally, whole plant bioassays and semi-field experiments were carried out with Myzus persicae. Our findings demonstrate the presence of temporal resistance against both aphid species in the primary sugar beet gene pool. Beet yellows virus (BYV) carrying aphids showed enhanced performance. Different levels of plant defense mechanisms were involved including resistance against Myzus persicae before reaching the phloem, particularly in sugar beet line G3. In contrast, resistance against Aphis fabae turned out to be predominately phloem-located. Furthermore, a high incidence of black inclusion bodies inside the stomach of Myzus persicae was observed for approximately 85% of the plant genotypes tested, indicating a general and strong incompatibility between sugar beet and Myzus persicae in an initial phase of interaction. Sugar beet resistance against aphids involved different mechanisms and is species-specific. The identification of these mechanisms and interactions represents a crucial milestone in advancing the breeding of sugar beet varieties with improved resistance. © 2023 Julius Kühn-Institut and The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Phytophagous Entomofauna of Tomato, Paprika and Eggplant Occurring on Plantations in Poland in 1919-2010 In Poland, in the years 1919-2010, in field crops of tomato (Lycopersicon esculentum Mill.), paprika (Capsicum annuum L.) and eggplant (Solanum melongena L.) there were found 52 phytophagous species belonging to 6 orders of insects: Orthoptera, Thysanoptera, Hemiptera, Coleoptera, Lepidoptera and Diptera. The number of pest species occurring on the different crops was: tomato - 39, paprika - 41, eggplant - 27. The presented phytophagous entomofauna proved to be stable in terms of species composition over the years of observations. However, there was a significant variation in population size, which was subject to considerable fluctuations in successive growing seasons. The dominant species posing a threat to plantations every year included: for tomato: Colorado potato beetle (Leptinotarsa decemlineata), green peach aphid (Myzus persicae), soil pests: cutworm (Agrotis sp), wireworms (Agriotes sp) and white grubs (Melolontha sp); for paprika: onion thrips (Thrips tabaci), green peach aphid (Myzus persicae), bugs (Lygus sp.); for eggplant: green peach aphid (Myzus persicae), Colorado beetle (Leptinotarsa decemlineatas), onion thrips (Thrips tabaci).

Sugar beet (Beta vulgaris) is an important arable crop, traditionally used for sugar extraction, but more recently, for biofuel production. A wide range of pests, including beet cyst nematode (Heterodera schachtii), root‐knot nematodes (Meloidogyne spp.), green peach aphids (Myzus persicae) and beet root maggot (Tetanops myopaeformis), infest the roots or leaves of sugar beet, which leads to yield loss directly or through transmission of beet pathogens such as viruses. Conventional pest control approaches based on chemical application have led to high economic costs. Development of pest‐resistant sugar beet varieties could play an important role towards sustainable crop production while minimising environmental impact. Intensive Beta germplasm screening has been fruitful, and genetic lines resistant to nematodes, aphids and root maggot have been identified and integrated into sugar beet breeding programmes. A small number of genes responding to pest attack have been cloned from sugar beet and wild Beta species. This trend will continue towards a detailed understanding of the molecular mechanism of insect–host plant interactions and host resistance. Molecular biotechnological techniques have shown promise in developing transgenic pest resistance varieties at an accelerated speed with high accuracy. The use of transgenic technology is discussed with regard to biodiversity and food safety.

Virus yellows in sugar beet is caused by different virus species. Monitoring has shown that Beet yellows virus (BYV), Beet mild yellowing virus (BMYV), Beet chlorosis virus (BChV) are common and widespread, while Beet mosaic virus (BtMV) is less prevalent. The green peach aphid (Myzus persicae) is considered the main vector of these viruses. Sugar beet varieties with resistance or tolerance traits are currently not available to practical growers, therefore it is imperative to support breeding efforts with improved strategies to achieve virus resistance. For this purpose, a field test was established in which yield differences between susceptible and tolerant varieties can be generated by a 3% inoculation with BMYV-carrying aphids. A greenhouse bioassay has also been developed to distinguish susceptible and tolerant genotypes following BYV infection. Both assays pave the way for future use of natural resources such as wild forms and other breeding material to screen for virus resistance. In addition, molecular biology approaches are used to identify plant susceptibility factors of the plant-virus interaction, which will be knocked out via modern precision breeding methods to generate recessive virus resistance. Consequently, genotypes with naturally occurring mutations in the appropriate factors can be used for crossbreeding processes into elite breeding material.

Questions: What is the relative importance of landscape variables compared to habitat quality variables in determining species composition in floodplain forests across different physiographic areas? How do species composition and species traits relate to effects of particular landscape variables? Do lowland and mountain areas differ in effects of landscape variables on species composition? Location: Southern Czech Republic. Methods: A total of 240 vegetation relevés of floodplain forests with measured site conditions were recorded across six physiographic areas. I tested how physiographic area, habitat quality variables and landscape variables such as current land-cover categories, forest continuity, forest size and urbanization influenced plant species composition. I also compared how mountain and lowland areas differ in terms of the relative importance of these variables. To determine how landscape configuration affects the distribution of species traits, relationships of traits and species affinity with landscape variables were tested. Results: Among landscape variables, forest continuity, landscape forest cover and distance to nearest settlement altered the vegetation. These variables also influenced the distributions of species traits, i.e. life forms, life strategies, affinity to forest, dispersal modes, seed characteristics, flooding tolerance and Ellenberg indicator values for nitrogen, light, moisture and soil reaction. Nevertheless, physiographic area and habitat quality variables explained more variation in species composition. Landscape variables were more important in lowland areas. Forest continuity affected species composition only in lowlands. Conclusions: Although habitat quality and physiographic area explained more vegetation variability, landscape configuration was also a key factor influencing species composition and distribution of species traits. However, the results are dependent on forest geographical location, with lowland forests being more influenced by landscape variables compared to mountain forests.

Plants release a diverse array of volatile organic compounds (VOCs) that play a role in interactions with other plants and arthropod herbivores. The potential of using plants that emit either repellent or attractive VOCs to help managing insect populations have been shown. However, the response of the green peach aphid (Myzus persicae), a major sucking insect pest worldwide, to VOCs from cabbage and infested with conspecific remains unknown. This study investigated how VOCs released by cabbage infested or uninfested by Myzus persicae influenced host selection in seven different cultivars. and compared under infested and non-infested conditions. Using headspace solid-phase microextraction gas chromatography coupled with mass spectrometry (SPME-GC-MS), we identified 22 VOCs from non-infested cabbage plants and 33 from aphid-infested plants across the seven cabbage cultivars. Infested plants emitted a greater diversity and higher amounts of volatiles, dominated by terpenes and green leaf volatiles. Caryophyllene was the only compound common in both infested and non-infested plants. In olfactometer assays, wingless Myzus persicae showed a significant attraction to conspecific-infested plants with the strongest response to the cultivar QG 80. However, this increased attraction was not consistent across all cultivars, highlighting the need for further studies to understand the ecological implications and potential benefits or drawbacks of this attraction. Our findings highlight the potential of using VOC-emitting trap crops for the targeted management of Myzus persicae. By identifying key volatiles that attract aphids, this study provides a foundation for developing eco-friendly pest control strategies. © 2025 Society of Chemical Industry.

Elicitors are biofactors that induce resistance in plants against different insect pests. This in vitro study evaluated the impact of a novel elicitor protein PeBC1, extracted from a necrotrophic fungus Botrytis cinerea, on the development and fecundity parameters of green peach aphid (Myzus persicae) on common beans (Phaseolus vulgaris L.). Three different concentrations of PeBC1 elicitor (i.e., 33.56, 25.43, 19.33 µg mL−1) were applied at three different temperature regimes (i.e., 18, 21, and 25 °C). Elicitor treatments were applied topically on the bean plants at 3-leaf stage and newly emerged (0–6 h old) apterous adult aphids were exposed to these treated leaves. In addition to the biological parameters of aphids, the relative expression levels of key genes associated with jasmonic acid (JA) and salicylic acid (SA) plant defense pathways were also determined through RT-qPCR. Results of bioassays revealed that the application of PeBC1 elicitor protein exhibited pronounced and significant (p < 0.05) sub-lethal effects on green peach aphids. The fecundity was reduced and the nymphal development time was prolonged by different concentrations of PeBC1 elicitor and temperature regimes. Gene expression studies showed that the exogenous application of PeBC1 induced a significant upregulation of the expression levels of JA and SA pathway-associated genes in bean plants. As compared to control, elicitor-treated plants exhibited an induced resistance against aphids. Our findings suggest the potential use of PeBC1 elicitor protein in future bio-intensive management strategies against sap-sucking insect pests such as green peach aphids.

Virus yellows (VY), caused by beet chlorosis virus (BChV), beet mild yellowing virus (BMYV) and beet yellows virus (BYV), is a serious disease affecting sugar beet, leading to significant yield losses. The main vector is the green peach aphid Myzus persicae . Beet mosaic virus (BtMV) is often associated with VY due to the shared vector. Different host plants of VY‐associated viruses can play an important role in the aphid's life cycle and the VY‐epidemiology. This study evaluated the susceptibility of 25 cover crops and flower strip plants to VY‐associated viruses as well as their attractiveness to M. persicae . None of the tested plants were susceptible to BYV or BtMV, while Gypsophila elegans tested positive for BChV and 13 species tested positive for BMYV. Seven of these, including important cover crops and flower strip plants such as Linum usitatissimum , Trifolium resupinatum , T. incarnatum and Centaurea cyanus , were identified as new BMYV hosts. Plant attractiveness to M. persicae varied widely. Under field conditions, only a few species, such as Sinapis alba or Raphanus sativus var. oleiferus , showed high levels of natural infestation by M. persicae . However, a field choice experiment revealed that BMYV infection can occur in different plants, even at low levels of M. persicae infestation. Field trials also confirmed that M. persicae can transmit BMYV from infected cover crops to sugar beet. The findings emphasise the potential importance of cover crops and flower strip plants as green bridges in VY‐epidemiology and highlight the need for research in large‐scale field studies.

Aphids are one of the major pests in agricultural crops. A number of synthetic pesticides have been used for control of aphids in agriculture, but increasing public concerns over their adverse effects on the environment have required more environmentally-friendly methods for pest management. In this study, we examined plant oil formulations for the control of green peach aphid (Myzus persicae). Oil formulations were prepared by hydrolyzing the plant oils in ethanolic KOH solution and diluted at the rate of 1:500 for aphid control. The oil formulations showed aphid mortalities ranging from 24.44 to 43.33% in vitro. Significantly increased aphid mortalities were observed by the treatment of oil formulations combined with low-dosed imidacloprid. No significant difference in the aphid mortality was observed between the oil formulations. Mass spectrometry analyses of aphids treated with the low dosedimidacloprid plus the plant oil formulations detected similar concentrations of imidacloprid between the treatments. In field trial bioassays against aphids, significantly decreased aphid population were observed in the pepper plants treated with soybean oil formulation combined with the low-dosed imidacloprid, while aphid population dramatically increased in the pepper plants treated with the low-dosed imidacloprid alone. These results suggested that the plant oil formulations can be used as an environmentally-friendly method for enhancing the insecticidal effectiveness, which may play a role in reducing the use of synthetic pesticide in agriculture.

Simple SummaryThe green peach aphid (Myzus persicae) is one of the most damaging insect pests affecting vegetable and ornamental crops worldwide, due to its feeding activity and ability to transmit plant viruses. Although synthetic chemical pesticides are commonly used to manage M. persicae, their widespread use raises concerns about human health, environmental contamination, pesticide residues in food, harm to beneficial insects, and the development of resistance. As a result, there is growing interest in safer, eco-friendly alternatives. In this study, we used sucrose-based artificial diet assays supplemented with double-stranded RNA (dsRNA) to identify RNA interference (RNAi) effectors capable of inducing gene silencing and mortality in M. persicae through ingestion. Defining effective gene targets is a critical first step toward developing a non-toxic, environmentally sustainable RNAi-based technology for controlling M. persicae and the viruses it spreads.Aphids are sap-sucking pests that cause substantial damage to fruit and fibre crops through direct feeding and transmission of plant viruses. While chemical pesticides remain the primary method of control, their use raises concerns related to human health, environmental contamination, pesticide resistance, and impacts on beneficial insects. As a sustainable alternative, spray-on double-stranded RNA (dsRNA) technology offers a promising approach to induce RNA interference (RNAi) in target pests. For RNAi to be effective against sap-sucking insects like the green peach aphid (Myzus persicae), it is essential to identify genes whose silencing disrupts vital physiological functions. In this study, artificial diet (AD)-based feeding assays were used to evaluate dsRNAs targeting eight genes involved in neural function, osmoregulation, feeding behaviour, and nucleic acid/protein metabolism. dsRNAs were administered individually, in combinations, or as a multi-target stacked construct. After 98 h of feeding, aphid mortality ranged from 14 to 72% (individual targets), 78–85% (combinations), and 54% (stacked construct). Transcript knockdown varied from 6.3% to ~54%, though a consistent correlation with mortality was not always observed. The gene targets and combinatorial dsRNA strategies identified in this study provide a foundation for developing RNAi-based crop protection technologies against M. persicae infestation.

ABSTRACTDuration of systemic pesticide activity under field conditions has wide implications for pest management. Our aim was to determine the duration of activity of systemic insecticides commonly used in cultivated tobacco (Nicotiana tabacum) by measuring the levels of insect infestations on field plots and effects on reproduction and survival of the green peach aphid (Myzus persicae) in controlled bioassays using field grown leaves. Plants were treated with different concentrations of two systemic neonicotinoid pesticides, imidacloprid and thiamethoxam, and grown in small field plots. Our results show that these materials are effective under field conditions against aphids for at least 13 weeks after transplant. Pesticides also affected aphid reproduction and nymph survival in bioassays, although some aphids survived on pesticide-treated leaves. We also observed that leaf age affected aphid survival. We showed that neonicotinoids were very effective against M. persicae, aphids are a useful organism to assess pesticide efficacy early in the growing season, but plant characteristics are more important than pesticide concentration in the second half of the growing season.

This study was conducted to evaluate the effectiveness of the biopesticides Palazin and Tondxier and the chemical pesticides Thiamethoxam and Acetamiprid against the green peach aphid Myzus persicae in the autumn season of 2021.The study showed that the Thiamethoxam and Palazin had the highest efficiency in controlling of the green peach aphid. The percentage of mortality was 85.00% and 38.33% insect/applied respectively, followed by the pesticide Acetamiprid, which was effective in mortality rate of 33.33% insect/applied after 24 hours of treatment. Thiamethoxam and the Palazin were the most efficient in controlling green peach aphid. The mortality percentage was 93.33 and 71.66% insects/application respectively, followed by the pesticide Acetamiprid, in which the percentage of effectiveness reached 63.33% insects/application after 48 hours of treatment.

Multi-infection of plants by viruses is very common and can change drastically infection parameters such as virus accumulation, distribution, and vector transmission. Sugar beet is an important crop that is frequently co-infected by the polerovirus beet chlorosis virus (BChV) and the closterovirus beet yellows virus (BYV), both vectored by the green peach aphid (Myzus persicae). These phloem-limited viruses are acquired while aphids ingest phloem sap from infected plants. Here we found that co-infection decreased transmission of BChV by ~50% but had no impact on BYV transmission. The drastic reduction of BChV transmission was due to neither lower accumulation of BChV in co-infected plants nor reduced phloem sap ingestion by aphids from these plants. Using the signal amplification by exchange reaction fluorescent in situ hybridization technique on plants, we observed that 40% of the infected phloem cells were co-infected and that co-infection caused redistribution of BYV in these cells. The BYV accumulation pattern changed from distinct intracellular spherical inclusions in mono-infected cells to a diffuse form in co-infected cells. There, BYV co-localized with BChV throughout the cytoplasm, indicative of virus-virus interactions. We propose that BYV-BChV interactions could restrict BChV access to the sieve tubes and reduce its accessibility for aphids and present a model of how co-infection could alter BChV intracellular movement and/or phloem loading and reduce BChV transmission.IMPORTANCEMixed viral infections in plants are understudied yet can have significant influences on disease dynamics and virus transmission. We investigated how co-infection with two unrelated viruses, BChV and BYV, affects aphid transmission of the viruses in sugar beet plants. We show that co-infection reduced BChV transmission by about 50% without affecting BYV transmission, despite similar virus accumulation rates in co-infected and mono-infected plants. Follow-up experiments examined the localization and intracellular distribution of the viruses, leading to the discovery that co-infection caused a redistribution of BYV in the phloem vessels and altered its repartition pattern within plant cells, suggesting virus-virus interactions. In conclusion, the interplay between BChV and BYV affects the transmission of BChV but not BYV, possibly through direct or indirect virus-virus interactions at the cellular level. Understanding these interactions could be crucial for managing virus propagation in crops and preventing yield losses.