Search Results (107)

In the field of smart plant protection, accurate early monitoring of winged aphids is critical, as it enables the interruption of viral disease transmission and reduces dependence on pesticides. In response to the core challenges of low efficiency in manual counting associated with current sticky trap-based monitoring, as well as the insufficient recognition accuracy and poor robustness of computer vision models in dense small-target scenarios, this study aims to develop a high-precision, highly reliable automated identification method for winged aphids. To achieve this, a specialized detection model named PCSNet is proposed. Based on YOLOv12, this model innovatively incorporates a coordinate attention mechanism to enhance the perception of spatial structures for small targets. Simultaneously, a shallow feature enhancement branch (SFEB) is introduced to enrich detailed information, and the Normalized Wasserstein Distance loss function is integrated to optimize bounding box regression. Comparative experiments conducted on a self-constructed dataset of sticky trap images encompassing complex field backgrounds demonstrate that the PCSNet model achieves optimal detection performance, with a mean average precision (mAP) of 0.791 and a precision of 0.866, significantly outperforming mainstream detection models and various attention mechanism variants. This research provides an effective technical solution for constructing a real-time and automated intelligent pest monitoring system, offering substantial application value for advancing the intelligent transformation of pest and disease monitoring and promoting practices in green prevention and control. Full article

Aphids are major agricultural pests worldwide, causing crop damage both through direct piercing-sucking feeding and the transmission of plant viruses. Their multistage life cycle, unique developmental physiology, plasticity in developing pesticide resistance, and multifaceted interactions with host plants and bacterial endosymbionts make effective control particularly challenging. In this review, we summarize the current toolbox available for aphid control across major crop systems, including chemical pesticides, biological agents, plant resistance, cultural practices, biorational control, and emerging strategies such as RNA interference (RNAi) and symbiosis-targeted approaches. Rather than providing an exhaustive survey of the literature, we draw on conceptual and illustrative studies to critically evaluate the strengths and limitations of each control strategy. Finally, we outline future directions for aphid control, highlighting the potential of modern technologies, such as artificial intelligence (AI), synthetic biology, data-driven analytics, and CRISPR-based genome editing, to expand and improve existing control options. Full article

Here, we adopt an historical approach towards reviewing research since the 1970s on the seed-borne virus diseases of cool-season pulses caused by pea seed-borne mosaic virus (PSbMV) in Australia’s grain cropping regions. All relevant investigations concerning the principal cool-season pulse crops infected; field pea, lentil, faba bean, chickpea, and the minor ones, Lathyrus species, vetches and narbon bean, are covered. However, as the PSbMV field pea pathosystem is the most studied, this receives greatest emphasis. The review starts with brief background information, and by describing the disease symptoms caused and the advances in sample testing procedures. Next, findings from past PSbMV studies are covered in greater detail including transmission by aphids, contact and seeds; occurrence in crops and seed stocks; pathotypes and genetic diversity; host resistance; and phytosanitary, cultural and chemical control measures. What these studies found about PSbMV biology, epidemiology and control is emphasized by describing past glasshouse and field experimentation. Then, practical research outcomes identifying PSbMV’s epidemic drivers, forecasting its epidemics and devising an integrated disease management strategy are emphasized. Examples of images that illustrate past investigations and research outputs are provided. Finally, principal research achievements and priorities for future Australian PSbMV cool-season pulse research are highlighted. Full article

Maize, as the global highest-yield grain crop, can impact social stability and security based on its annual yield. Given that maize viruses have caused up to 91% yield reductions, investigating maize virus diseases is of the utmost importance. In July 2020, a suspected maize yellow mosaic virus (MaYMV) was discovered in a maize field, and a MaYMV detection protocol was established. The MaYMV isolate MA70, discovered in a maize plant from Wuri District, Taiwan, in November 2022, was shown to infect both maize 42 days post-inoculation (dpi) and wheat (35 dpi), causing mosaic symptoms, through aphid transmission with corn leaf aphid (Rhopalosiphum maidis). To determine the whole genome sequence of MA70, a 5642 bp sequence was obtained using RT-PCR and Sanger sequencing. Sequencing results indicated a 94.8–96.8% nucleotide sequence similarity with 54 MaYMV isolates from GenBank and with amino acid sequence identities exceeding 90% for all MaYMV proteins. Phylogenetic analysis showed the relationship of MA70 is closest to the Chinese isolate. The nucleotide sequence identity was lower among isolates of more distinct geographical clusters. Between October 2023 and January 2024, survey results indicated that MaYMV prevalence in corn fields across six areas in Taichung reached 17.5% (130/743 plants) and was present in all the sampled fields. MaYMV was present in all sampled fields affirming its ubiquitous presence. This study establishes the first documented case of MaYMV in Taiwan; however, survey findings hint at a potential pre-existing presence in Taiwanese maize fields. Therefore, this research also develops a practical diagnostic tool for field monitoring of MaYMV prevalence, which is crucial for informing future disease management strategies, including the critical need for cross-strait between Taiwan and China collaboration on viral disease surveillance. Full article

The red flower aphid (Uroleucon gobonis) is a significant agricultural pest causing damage via direct feeding and virus transmission. Chemical sensory proteins (CSPs) are critical for insecticide resistance, mediating the detection of semiochemicals or the sequestration of neuroactive insecticides. This study provides the first comprehensive identification and functional characterization of chemosensory gene families in Uroleucon gobonis to elucidate their roles in chemoperception and resistance. We conducted de novo transcriptome sequencing and assembly to identify chemosensory genes. Their phylogenetic relationships and structural motifs were analyzed. Developmental expression patterns were assessed via RNA-seq, and tissue-specific expression was validated using quantitative real-time PCR (qRT-PCR). We identified 40 chemosensory genes: 12 odorant-binding proteins (OBPs), 8 CSPs, 14 odorant receptors (ORs), and 6 gustatory receptors (GRs). Phylogenetic analysis revealed species-specific adaptations, including the absence of GR clades 2/4 and minimal representation in CSP Subgroup III. Structural motifs were highly conserved in ORs/OBPs but divergent in CSPs/GRs. RNA-seq identified 1896 differentially expressed genes (DEGs) between instars, including stage-specific regulation of UgobCSP4, UgobCSP6, UgobOBP3, and UgobOBP10. qRT-PCR confirmed extreme spatial expression, such as leg-specific UgobCSP6 and antennae-specific UgobOBP10. These findings elucidate key molecular adaptations in chemosensory gene families governing perception and potential insecticide resistance in Uroleucon gobonis. The identified stage- and tissue-specific genes provide targets for developing species-specific pest control strategies. Full article

Symbiosis between rhizobia and legumes can affect plant tolerance to abiotic and biotic stressors such as drought and herbivores. Yet few studies have assessed how soil rhizobia impact plants that face abiotic and biotic stress simultaneously. This is a major knowledge gap given that many aspects of plant growth and defense are affected by interacting stressors, and these interactions can affect legume–rhizobia symbiosis. Here we assessed rhizobia-mediated interactions between a legume host (Pisum sativum), a vector herbivore (pea aphid, Acyrthosiphon pisum), a plant virus (pea enation mosaic virus, PEMV), and soil water availability. We show that rhizobia promoted plant growth and mitigated osmotic stress caused by reduced soil water availability. Rhizobia also increased plant tolerance to PEMV under high soil moisture conditions but had no measurable effect on PEMV when plants were grown in soil with reduced water. To assess the mechanisms that mediated these complex interactions, we measured gene transcripts related to phytohormone signaling and found that salicylic acid, jasmonic acid, abscisic acid, and ethylene signaling were affected by interactions between rhizobia and water availability; each of these pathways affects PEMV transmission. Our study shows that beneficial effects of rhizobia on legumes are impacted by abiotic and biotic stress, and outcomes of symbiosis may be context-dependent in field settings. Full article

The bird cherry–oat aphid (Rhopalosiphum padi L.) constitutes approximately 70–80% of all aphid individuals found on cereal crops in Poland. It is considered one of the most economically important cereal pests, causing indirect damage through virus transmission and leading to substantial yield losses in agricultural crops. Previous studies have shown that the anholocyclic development of this species is strongly correlated with temperature patterns. Between 2018 and 2022, an analysis of the population structure of R. padi (gynoparae, males, and anholocyclic forms) was conducted during the autumn periods using a Johnson suction trap in Western Poland (Greater Poland region), in an area cultivated mainly with cereals. In years with a higher number of days characterized by mean daily air temperatures known to induce changes in R. padi biology, a marked decrease in the proportion of males within autumn populations was observed, along with a delayed onset of their occurrence. In each year of the study, temperature conditions conducive to the development of anholocyclic forms of R. padi were recorded. The abundance of individual morphs and forms of R. padi in autumn collections using the Johnson suction trap was distinctly variable and characterized primarily by a relatively low proportion of males in the catches (except for the years 2020–2021) within the total number of aphids of this species collected. An opposite trend was observed in these years regarding the proportion of anholocyclic forms of R. padi (2.61% of the entire population in 2020 and 3.51% in 2021). Full article

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. Full article

Aphids remain exceptional models for symbiosis research due to their unique experimental advantages that extend beyond documenting symbiont-mediated phenotypes. Nine commonly occurring facultative bacterial symbionts provide well-characterized benefits, including defense against parasitoids, pathogens, and thermal stress. Yet the system’s greatest value lies in enabling diverse research applications across biological disciplines through experimental tractability combined with ecological realism. Researchers can create controlled experimental lines through symbiont manipulation, maintain clonal host populations indefinitely, and cultivate symbionts independently. This experimental power is complemented by extensive knowledge of symbiont dynamics in natural populations, including temporal and geographic distribution patterns—features generally unavailable in other insect-microbe systems. These advantages facilitate investigation of key processes in symbiosis, including transmission dynamics, mechanisms, strain-level functional diversity, multi-partner infections, and transitions from facultative to co-obligate relationships. Integration across biological scales—from genomics to field ecology—enables research on symbiont community assembly, ecological networks, coevolutionary arms races, and agricultural applications. This combination of experimental flexibility, comprehensive natural history knowledge, and applied relevance positions aphids as invaluable for advancing symbiosis theory while addressing practical challenges in agriculture and invasion biology. Full article

Potato leafroll virus (PLRV, species Polerovirus PLRV) is a major pathogen affecting potatoes worldwide. Since 2018, PLRV incidence has increased in Scottish potato crops. Deep sequencing of PLRV in Scottish potato plants revealed the prevalence of a novel PLRV type which became predominant in 2023, displacing the phylogenetically distinct variants that have been present in the region since at least 1989. Analysis of the infection dynamics of the cDNA clone-derived PLRV isolates in potato plants indicated that the novel PLRV may accumulate to higher levels compared to the historic one. Analysis of the genetic diversity of PLRV in early and late field generations (FGs) of seed potatoes showed a significantly reduced genetic diversity of the PLRV structural genes in the early FGs compared to the late FGs, while divergency of the non-structural genes remained similar across all FGs. Considering that late FGs are more likely to be infected with PLRV via tuber transmission, and early FGs via aphid transmission, these findings suggest that aphid transmission imposes a genetic bottleneck on the structural genes of PLRV, but not on its non-structural genes. Full article

Common bean (Phaseolus vulgaris L.), the world’s most widely grown legume crop, is not only of great commercial importance but is also a vital smallholder crop in low-to-medium-income countries. In sub-Saharan Africa common bean provides consumers with a major proportion of their dietary protein and micronutrients. However, productivity is constrained by viruses, particularly those vectored by aphids and whiteflies, and problems are further compounded by seed-borne transmission. We describe common bean’s major viral threats including the aphid-transmitted RNA viruses bean common mosaic virus and bean common mosaic necrosis virus, and the whitefly-transmitted begomoviruses bean golden mosaic virus and bean golden yellow mosaic virus and discuss how high-throughput sequencing is revealing emerging threats. We discuss how recent work on indirect and direct viral ‘manipulation’ of vector behaviour is influencing modelling of viral epidemics. Viral extended phenotypes also modify legume interactions with beneficial organisms including root-associated microbes, pollinators and the natural enemies of vectors. While problems with common bean tissue culture have constrained transgenic and gene editing approaches to crop protection, topical application of double-stranded RNA molecules could provide a practical protection system compatible with the wide diversity of common bean lines grown in sub-Saharan Africa. Full article

Broad bean is one of the most important leguminous crops worldwide. However, its productivity is greatly affected by the infestation of Aphis fabae and Aphis craccivora (Hemiptera: Aphididae). The main objective of the current study was to identify the most susceptible phenological stages of the broad bean variety (Histal) against black aphids’ herbivory. This had been achieved through an evaluation of plant resistance mechanisms such as antixenosis and antibiosis. The results regarding an antixenosis test revealed that the four tested phenological stages of V. faba did not have a significant effect on the preference of A. craccivora and A. fabae towards the crop plant. Overall, a slightly higher number of adults settled on the three and four unfolded leaves’ stage of the crop plant. Similarly, the highest number of developed embryos were found in the four leaves’ stage of the crop, and the lowest in the second leaf stage. The adult body size of A. craccivora was slightly larger in the case of the three unfolded leaves. Furthermore, the maximum body size of A. fabae adults was recorded in the case of the first unfolded leaf stage crop. Linear correlations between the biological parameters for both species revealed only one significant relationship between developed and total embryos for A. craccivora. The results of the current study highlight the need to protect broad bean crops against infestations of black aphids, i.e., A. craccivora and A. fabae. This is essential for reducing direct damage and preventing the transmission of phytoviruses. However, future studies should aim to evaluate the susceptibility of all developmental phenological stages of the crop against black aphids to mitigate potential crop losses. Full article

Sugar beet (Beta vulgaris ssp. vulgaris) is a vital crop, contributing to nearly a quarter of global sugar production, but faces significant challenges from biotic stressors, particularly aphids, which transmit damaging yellowing viruses such as Beet Yellow Virus (BYV) and Beet Mild Yellowing Virus (BMYV). Following the partial ban of neonicotinoids in Europe, viral infections in sugar beet have surged, highlighting the need for a deeper understanding of aphid-mediated virus transmission mechanisms. This study aims to evaluate the transmission efficiency of BYV and BMYV through different clones of the aphid vector Myzus persicae from sugar beet seed companies across Europe, and to analyze the feeding behaviors of efficient clones to identify factors influencing virus transmission. The transmission rates of yellowing viruses by M. persicae clones ranged from 52% to 79% for BMYV (mean 65%) and 7% to 96% for BYV (mean 47%). While no significant differences in BMYV transmission efficiency were observed among clones, a significant difference was detected between two BYV-carrying clones. Moreover, the BYV-carrying clone exhibited prolonged penetration activities during its feeding phase compared to the BMYV-carrying clone, suggesting a potential behavioral influence on transmission efficiency. This study highlights the importance of considering aphid clone influence in the development of sugar beet resistance. Full article

Aphis gossypii is a significant global pest that impacts numerous agricultural crops and vegetables, causing direct damage to food plants and indirect damage through the transmission of phytopathogenic viruses, primarily begomoviruses. In Panama, particularly in the Azuero region, viral infections transmitted by this aphid can affect a substantial share of tomato crops cultivated for industrial use. A traditional alternative to synthetic pesticides involves exploring plant extracts with insecticidal properties derived from wild plants found in our tropical forests, which can be easily prepared and applied by farmers. In this context, the present research aimed to evaluate the insecticidal activity of ethanolic extracts from the stems and leaves of Sphagneticola trilobata on both nymphs and adults of A. gossypii. Mortality was assessed at 24, 48, and 72 h after applying three doses of each extract (25, 50, and 100 µg/L). A standard phytochemical analysis to determine insecticidal activity revealed that both extracts exhibited significant efficacy at the highest concentration tested; however, the leaf extract demonstrated greater effectiveness at lower concentrations. A comprehensive metabolomic study indicated that the active compounds are diterpenes derived from the pimarenyl cation. These compounds have been extensively documented for their insecticidal potential against various insect species, suggesting that ethanolic extracts from this plant could serve as viable candidates for agricultural insecticides to combat aphid infestations. Full article

Soybean mosaic virus (SMV) causes systemic infections in soybean plants, leading to chlorotic mosaic and significant yield losses. In Argentina, during the 1990s, three isolates were collected in Marcos Juárez (MJ), Manfredi (M), and Northwestern Argentina (NOA), along with the “Planta Vinosa” (PV) isolate, which causes severe necrosis in some cultivars. These isolates were freeze-dried and stored at −70 °C for several years. They were recovered by mechanical inoculation and biologically, molecularly, and physiologically characterized for the first time. Three of the four isolates showed low genetic divergence in the P1, CI, and CP genes. Although SMV-NOA and SMV-PV had high nucleotide sequence identity, they differed in pathogenicity, seed mottling, and transmission efficiency by seeds or aphids. SMV-NOA caused early changes in photosystem II quantum efficiency (ɸPSII) and malondialdehyde (MDA) content before symptom expression (BS). After symptom development (LS), SMV-M significantly increased MDA, total soluble sugars, and starch compared to the other isolates. Thus, early changes in ɸPSII and sugars may influence late viral symptoms. Likewise, SMV-MJ induced more severe symptoms in the susceptible Davis cultivar than in Don Mario 4800. Therefore, our results demonstrate genomic, biological, and physiological differences among SMV isolates and variable interactions of SMV-MJ with two soybean cultivars. Full article