Common ragweed, Ambrosia artemisiifolia L., a noxious invasive plant, produces novel secondary metabolites. However, it attracts soybean aphid, Aphis glycines, a significant pest of soybean, to feed on it. Elucidating the molecular mechanisms of A. glycines adaptation to A. artemisiifolia may help identify target genes useful for pest management. High-throughput transcriptome sequencing identified 4250 differentially expressed genes (DEGs), with 2399 upregulated and 1851 downregulated. KEGG pathway enrichment analysis suggested that these DEGs were significantly involved in core detoxification-related pathways, including metabolism of xenobiotics by cytochrome P450, drug metabolism, ascorbate and aldarate metabolism, and pentose and glucuronate interconversions. Further analysis revealed significant upregulation of 17 UDP-glycosyltransferase (UGT) genes, with AgUGT342B2, AgUGT343B2, AgUGT344J2, AgUGT344L2, and AgUGT344N2 showing 6.34-, 6.22-, 2.14-, 3.98-, and 7.49-fold higher expression, respectively, than in A. glycines fed on soybean. Bioassays demonstrated that A. glycines reared on A. artemisiifolia exhibited significantly reduced sensitivity to three common insecticides, imidacloprid, thiamethoxam, and lambda-cyhalothrin, with LC50 values increasing by 5.8-fold, 2.8-fold, and 3.6-foldhigher, respectively, than those reared on soybean. These findings indicate that feeding on A. artemisiifolia induces UGT gene family upregulation in A. glycines, conferring cross-resistance to multiple insecticide classes. This study reveals a molecular mechanism linking host adaptation to insecticide resistance, highlighting the ecological and evolutionary consequences of invasive plant-herbivore interactions.

Soybean aphids (Aphis glycines) (Hemiptera: Aphididae) pose a serious threat to global soybean production, necessitating sustainable control strategies. This study investigated silica nanoparticles (SiNPs) as an eco-friendly alternative, hypothesising they would suppress aphid populations while enhancing plant growth. Soybean plants were foliar-sprayed with SiNPs (0-1 mmol/L), and aphids were assessed across six assays: fecundity, survival, feeding preference, weight gain, olfactory response, and plant morphometrics. SiNPs significantly reduced aphid nymphal production and population growth at all concentrations but did not affect survival, weight gain, or host-seeking behaviour. Plant responses were mixed: leaf width increased at higher SiNPs doses, but plant height decreased, with no effects on leaf length, root/shoot biomass, or root length. These findings suggest that SiNPs could disrupt aphid reproduction without triggering behavioural avoidance. The absence of biomass reduction indicates potential for crop compatibility. This laboratory study reveals a novel, reproduction-targeted mode of action for SiNPs, highlighting its potential as a candidate for future development in sustainable IPM strategies. Further field-scale validation is required to confirm these effects under real-world conditions.

Abstract The demand for soybeans, one of Indonesia’s essential food commodities, continues to increase annually; however, this has not been accompanied by a corresponding rise in national production. Extensification through agroforestry systems offers a potential solution, considering Indonesia’s vast forest area of approximately 126 million hectares. Nevertheless, agroforestry systems also present certain limitations, such as low light intensity and high humidity. Elevated humidity levels may create favorable conditions for the development of plant diseases, including those caused by viruses. Therefore, this study aimed to investigate the symptoms and incidence of virus-associated diseases, as well as to identify the types and population density of insect vectors attacking soybean. This study was conducted at the Alas Bromo Forest for Special Purposes, Karanganyar, from April to July 2024, using a randomized complete block design (RCBD) with soybean varieties Grobogan, Anjasmoro, Dena-1, and Dena-2. The results revealed virus-like symptoms, including uneven leaf surfaces, vein clearing, and vein banding. The incidence of viral disease was ranked from lowest to highest as follows: Dena-1, Grobogan, Dena-2, and Anjasmoro varieties, with values of 40.3%, 43.2%, 49.2%, and 50.2%, respectively. Insect vectors identified in the field included Phenacoccus sp. and Aphis glycines .

The soybean aphid, Aphis glycines Matsumura, is a major pest that can significantly reduce soybean yields during heavy infestations. Planting resistant varieties is essential for managing this pest, requiring effective breeding and screening. In the United States, Dowling is resistant while Williams 82 is susceptible to A. glycines. This study assessed A. glycines from Harbin, China, feeding on soybean varieties Dowling, Williams 82, Shennong 9, and line P 3 under controlled conditions. Results showed that A. glycines thrived on Dowling and Williams 82, with no significant differences in longevity, oviposition, or fecundity. Line P 3 showed greater resistance to A. glycines than Dowling, with shorter adult longevity and lower fecundity. Shennong 9 was more susceptible than Williams 82, exhibiting longer adult longevity and higher fecundity. P 3 may serve as a valuable resource for breeding resistant soybeans, while Shennong 9's susceptibility could aid in control strategies. These results are crucial for developing A. glycines-resistant soybean varieties.

Investigating the combined effects of climate change and species interactions on species advances climate change research. However, such combined effects are understudied and may defy current hypotheses that focus on individual effects. We empirically examined how multiple environmental stressors (elevated temperature and CO2) and trophic interactions (herbivory and predation) interactively affect crop performance and pest control in a tri-trophic agroecosystem including soybean (Glycine max), aphid (Aphis glycines), and ladybeetle (Coccinella septempunctata). Temperature (control/+2°C/+4°C), CO2 (ambient/elevated), and trophic treatments (soybean/soybean-aphid/soybean-aphid-ladybeetle) were conducted in environmental chambers. Plant, herbivore, and predator traits (soybean nutrient content, defense, reproduction, and aphid and ladybeetle performance) were greatly influenced by interactions between abiotic (temperature, CO2) and biotic (trophic) factors, often contradicting current hypotheses. For example, aphids reduced seed number; ladybeetles generally suppressed aphids and rescued seed production. However, this biocontrol was compromised under elevated temperature and CO2, suggesting climate-induced changes in biocontrol effectiveness. We conclude: (1) To improve predictability, climate change research should include abiotic-biotic interactions as important mechanisms. (2) Empirical studies considering local climate-trophic interactions are critical for predicting regional food security. (3) While this study highlights species' plastic responses to climate change, experimental evolutionary studies will be needed to understand potential evolutionary adaptation.

Soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), is a major pest of soybean fields. While high-temperature stress induced by global warming can initially suppress aphid populations, these pests may eventually adapt, leading to more severe infestations and crop damage. Heat shock proteins (HSPs), which are upregulated in response to heat stress to protect aphid development, also confer tolerance to other abiotic stressors, including insecticides. To investigate the role of HSPs in insecticide resistance in A. glycines, we analyzed the expression profiles of three AgHsp90 genes (AgHsp75, AgHsp83, and AgGrp94) following exposure to high temperatures and insecticides. Functional validation was performed using RNA interference (RNAi) to silence AgHsp90 genes. Our results demonstrated that AgHsp90 genes were significantly upregulated under both heat and insecticide stress conditions. Furthermore, after feeding on dsRNA of AgHsp90 genes, mortality rates of A. glycines significantly increased when exposed to imidacloprid and lambda-cyhalothrin. This study provides evidence that AgHsp90 genes play a crucial role in mediating thermal tolerance and insecticide resistance in A. glycines.

A two-year field trial was conducted during Kharif seasons of 2021 and 2022 at the Experimental Research Farm of Department of Entomology, School of Agricultural Sciences, Nagaland University, Medziphema campus on soybean variety JS 335 in order to study the population dynamics of major sucking insect-pests and their natural enemies in relation to weather parameters. Randomized Block Design (RBD) with three replications was used for the study. Three major sucking insect-pests namely, aphid (Aphis glycines Matsumura), whitefly (Bemisia tabaci Gennadius) and pod sucking bug (Riptortus pedestris Fabricius) and one coccinellid predator (Coccinella transversalis) were recorded during the various growth stages of the crop. In both the seasons of investigation, the peak population of aphid (23.33 aphids/leaf in 2021 and 24.33 aphids/leaf in 2022), whitefly (23.67 whiteflies/leaf in 2021 and 21.67 whiteflies /leaf in 2022) and pod sucking bug (4.00 adults/mrl in 2021 and 4.33 adults/mrl in 2022) was observed on 35th, 33rd and 38th standard meteorological week (SMW), respectively. The population of ladybird beetle recorded was ranged from 0.22 to 1.75 beetles/mrl during kharif, 2021 and 0.16 to 1.83 beetles/mrl during kharif, 2022. The findings from this investigation gives a brief idea about the peak activity of the insects in a season and also the impact of weather factors on the major sucking insect-pests of soybean.

BackgroundThe colocalization of two resistance (R) genes on chromosome 13 of soybean (Glycine max (L.) Merrill) that confer resistance against the soybean aphid (Aphis glycines) and soybean mosaic virus (SMV) gives rise to a very unique R-avr tritrophic incompatible interaction system that goes across biological kingdoms. In this tritrophic system, the insect is the only natural vector of the virus and soybean is a host-plant for both pests/pathogen. The almost unavoidable co-evolution of pathogen-vector with that of the R-genes in soybean plants through an endless arms race to avoid each other’s defense-attack mechanisms raises interesting questions. The objectives of this work were to (i) develop double-resistant recombinant inbred lines (RILs) with a Rag2-Rsv1-h gene haplotype in coupling phase using resistance alleles from two different genetic sources (PI 243540 (Rag2) and Suweon 97 (Rsv1-h)), (ii) confirm phenotypically the resistant reaction against both pests in double-resistant RILs, and (iii) dissect the Rag2-Rsv1-h region with molecular markers and investigate the potential for structural variation.ResultsWe observed a recombination event in identified double-resistant F3:5 RILs in a region of chromosome 13 ca. 21 kb long (between positions 30,297,227 and 30,318,949 in Wm82.a2.v1) that lies between the reported locations of the Rsv1-h and Rag2 genes (29,815,463--29,912,369 and 30,412,581--30,466,533 intervals, respectively, based on Wm82.a2.v1), indicating the double-resistant haplotype is in coupling phase. The tight LD estimates obtained between haplotype markers underscored the physical proximity of the two resistance genes. Only 10 recombinant haplotype classes (excluding double heterozygotes) were observed among the 51 that were possible with a four loci haplotype. The 10 recombinant classes represented 15 out of 192 screened individuals. A joint SMV-aphid phenotypic greenhouse screen allowed us to identify the best aphid biotype 1 and SMV-G1, double resistant haplotype class in recombinant progeny. Our molecular marker results agree with previous fine-mapping reports and preclude the presence of resistance genes other than Rag2 and Rsv1-h in double-resistant RILs. A comparative genomic hybridization analysis revealed no obvious structural variants in the region.ConclusionsTo our knowledge, this is the first report of double-resistant Rag2-Rsv1-h soybean RILs that used a plant-insect-pathogen tritrophic system for germplasm enhancement. The co-occurrence of Rag and Rsv genes in a region that clusters resistance genes on chromosome 13 may be a unique feature of domesticated soybean. The recombinant genotypes will be useful in breeding to develop soybean cultivars with resistance to both the vector and the virus. The parental and recombinant genotypes may be helpful in future studies to elucidate interesting evolutionary questions regarding vector, host, and virus tritrophic systems.

Abstract Invasions by insect species that become pests are an increasing problem for agriculture. Introductions of parasitoids from the regions of pest origin and breeding plants resistant to invasive pests can reduce invasive pest abundance and impact. Whether interactions between parasitoids and plant resistance are positive or negative depends on the detailed mechanisms. We studied the effects of susceptible versus resistant soybean and avirulent versus virulent soybean aphid on the parasitoids Aphelinus certus and Aphelinus glycinis, the first with a broad host range and the second with a narrow host range. Both parasitoid species parasitized virulent aphids at least as much as avirulent aphids on susceptible and resistant soybean. Aphelinus certus parasitized fewer avirulent aphids than virulent aphids on resistant soybean and fewer avirulent aphids on resistant versus susceptible soybean. The numbers of aphids parasitized by A. glycinis did not vary with the treatments. Emergence rates of parasitoid progeny were high for both parasitoids and did not vary with the treatments. Progeny sex ratios of the parasitoids did not vary with plant resistance or aphid virulence. However, for A. certus there was a small effect of the interaction between plant resistance and aphid virulence. Body masses of female and male progeny of A. certus did not vary with the treatments. However, body masses of female progeny of A. glycinis were larger on susceptible versus resistant soybean and on virulent versus avirulent aphids. Body masses of male progeny of A. glycinis were larger on susceptible versus resistant plants. Parasitism by A. certus is known to be density‐dependent, and given that density‐dependent parasitism has been found in several other species of Aphelinus, parasitism by A. glycines is very likely also to be density‐dependent. Given the higher densities of virulent versus avirulent aphids on resistant soybean reported in the literature, these parasitoids should parasitize more virulent than avirulent aphids on resistant soybean and would limit the abundance of virulent soybean aphid if much of the soybean acreage had resistant plants. Little research has been published previously on the combined impacts of plant resistance and herbivore virulence on parasitoids. If our results hold true in other systems, plant resistance and biological control may be more compatible in suppressing herbivore virulence than has sometimes been proposed.

Natural host-plant resistance provides a sustainable solution to control insect outbreaks but can be limited due to insect counter-adaptation. The exact mechanisms of insect adaptation to host-plant resistance remain unclear in most systems. Some insect adaptations are controlled by epigenetic mechanisms, such as through noncoding RNA. PIWI-interacting RNAs are specific noncoding RNAs that bind with PIWI proteins to control a diverse range of gene regulatory functions, particularly in insects. Previous investigation into aphid PIWI gene copies showed expansion in their abundance compared to other insects, which may suggest PIWI genes have additional functions among aphids. We first characterized PIWI gene evolution through a phylogenetic analysis, then investigated the role of PIWIs by examining gene expression in the soybean aphid (Aphis glycines), a significant insect pest of soybean which has adapted to overcome aphid-resistance in host plants. Our data indicated the presence of three PIWI ortholog groups, as well as taxon-specific gene expansions, with gene copy numbers ranging from 3 to 17 across species. To evaluate a potential role of PIWIs in overcoming host-plant resistance, we measured their gene expression in Ap. glycines with (virulent) and without (avirulent) the ability to survive on aphid-resistant soybean. We found that virulent Ap. glycines have significantly higher expression of 2 PIWI genes (Agl1.1 and Agl1.3) compared to the avirulent biotype. These data suggest that gene regulatory mechanisms related to the PIWI pathway, potentially including piRNAs, are important in aphid systems and may enable adaptation to host-plant resistance.

The adverse effects of 33 typical pesticides in dry and paddy lands in typical cultivation areas of China were investigated. First, the resistance and cross-resistance (for target organisms), toxicity, and joint toxicity (for nontarget organisms) of pesticides were evaluated, and nine pesticides with high resistance, three with wide cross-resistance, nine with high toxicity, and one with wide joint toxicity were screened. Second, the optimal synergist control schemes in dry and paddy lands were developed, under which resistance to target organisms (corn aphid, soybean aphid, and rice water weevil) reduced by 23.46%, 46.06%, and 26.36% (maximum), respectively, and toxicity (neurotoxicity and developmental toxicity) to nontarget organisms (ladybird beetle, parasitic wasp, and Chinese mitten crab) reduced by 38.83%, 17.76%, and 15.94% (maximum), respectively. Third, the multitoxicity (neurotoxicity, metabolic toxicity, developmental toxicity, carcinogenicity, reproductive toxicity, and respiratory toxicity) adverse outcome pathway based on human health risk was constructed, and 10 pesticides with higher risk and composite risk were identified. Finally, the total exposure risk of 33 typical pesticides was predicted, and a priority control list was proposed. This study provides theoretical guidance for controlling pesticide application to achieve the green and sustainable development of agricultural soils.

Soybean aphid (Aphis glycines) is one of the main pests on soybeans, which causes serious damage to the soybean worldwide. The current genome of the soybean aphid is quite fragmented, which has impeded scientific research to some extent. In this study, we assembled a chromosome-level genome of the soybean aphid using MGI short reads, PacBio HiFi long reads and Hi-C reads. The genome sequence was anchored to four pseudo-chromosomes, with a total genome length of 324 Mb and a scaffold N50 length of 88.85 Mb. We evaluated the genome based on insecta_odb10 and the results show it has a completeness of 97.2%. A total of 20,781 protein-coding genes were predicted in the genome, of which 17,183 genes were annotated in at least one protein database. Our work provides a new genomic resource for the soybean aphid study.

Insect herbivore evolution is tightly linked to changes in their host plants. Many plants have defensive traits that enable them to naturally tolerate and/or deter insect herbivory (host plant resistance; HPR). Some insects have adapted to overcome or resist these defenses (virulence). Global climate change may exacerbate insect virulence, although these interactions have not been closely examined. We tested how one abiotic stressor, flooding, affects interactions between soybeans and two different biotypes of the invasive, soybean aphid (Aphis glycines). In laboratory assays, flooding suppressed avirulent aphid population growth but had no impact on virulent conspecifics, indicating a differential fitness response between biotypes. We also used RNA sequencing to compare flooding stress impacts on gene expression in virulent and avirulent aphids. There were strong, constitutive differences between biotypes regardless of flooding stress, with virulent aphids upregulating putative effector genes and differentially expressing genes involved in epigenetic regulatory processes. Within each biotype, transcriptomic changes due to flooding were limited, but overall, fewer genes were differentially expressed in virulent aphids in response to stress treatments. Our data suggested that virulence adaptations in soybean aphids may also confer greater resiliency to abiotic stress, which could accelerate selection for virulence as climate change effects intensify.

Abstract Corn and soybeans account for most of the agricultural land use in Iowa. Farmers must manage insect pests feeding on these crops throughout the growing season. Western corn rootworm, Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae), and soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), are currently considered the most important pests of corn and soybean, respectively, in Iowa. We explore the rates at which genetic resistance has developed in these pests, tactics to delay resistance evolution, and the relative success of these methods. The documented occurrence of Bt-resistant (Bacillus thuringiensis Berliner) western corn rootworm in Iowa is greater than for pyrethroid-resistant aphids. The perceived risk of resistance and adoption of insect resistance management strategies by farmers for each pest may be more critical than which pest has evolved resistance faster. While farmers are required to practice insect resistance management when using Bt corn for western corn rootworm, similar requirements do not exist for using insecticides for soybean aphid. We suggest that more robust insect resistance management strategies along with integrated pest management practices need to be adopted for both species. Specifically, for soybean aphid, scouting and monitoring soybean fields throughout the summer and following the economic threshold to decide on the need for foliar insecticide applications is strongly recommended. For western corn rootworm, insect resistance management strategies, such as crop rotation and the mandatory use of refuge when planting Bt corn are recommended. Farmers’ compliance to insect resistance management and integrated pest management practices impacts the rates of resistance evolution to management tactics for these pests.

Evaluation of insecticides for management of soybean aphid, 2025

The soybean aphid (Aphis glycines) is an invasive insect pest that continues to cause large-scale damage to soybean crops in the North Central United States. Recent empirical evidence points to differential fitness in the pestiferous aphid biotypes under abiotic stresses such as flooding. As climate change predicts increased flooding in the North Central United States, mathematical models that incorporate such factors are required to better inform pest management strategies. Motivated by these empirical results, we considered the effect of non-smooth Allee type mechanisms, for the two species Lotka-Volterra competition model. We showed that this mechanism can alter classical competitive dynamics in both the ordinary differential equation (ODE) as well as the spatially explicit setting. In particular, an Allee effect present in the weaker competitor could lead to bi-stability dynamics, as well as competitive exclusion reversal. We discuss applications of our results to pest management strategies for soybean aphids in the context of a changing climate.

The soybean aphid, Aphis glycines Matsumura, 1917, is a crucial soybean pest. Cultivated soybean, Glycine max (Carl von Linné) Elmer Drew Merrill, 1917, and wild soybean, Glycine soja Philipp Franz von Siebold & Joseph Gerhard Zuccarini, 1843, are summer hosts of A. glycines. In this study, the development, reproduction, and morphogenesis of A. glycines fed wild soybean (AgFW) were studied at different temperatures and photoperiods. The data were compared with that of A. glycines fed soybean (AgFS). At 20-29 °C, the adult lifespan of the first-third-generation AgFW was shorter than or equal to that of AgFS. Significant differences existed in the adult fecundity and intrinsic rate of increase between AgFW and AgFS. At a 10L:14D h photoperiod, males of AgFW were deposited earlier than, or as early as, males of AgFS. At 17 °C, the gynoparae of AgFW were deposited in proportions greater than or equal to those of AgFS. Based on these results, we concluded that the adaptability of AgFW and AgFS to temperature and photoperiod significantly differs. It is important to understand the life cycle of A. glycines in Harbin, northeast China, and formulate an integrated pest management strategy for A. glycines in the region.

In 2019, random samples of Panicum miliaceum growing as a weed were surveyed to uncover their virus infections at two locations in Hungary. This pilot study revealed infection with three viruses, two appearing for the first time in the country. As follow-up research, in the summer of 2021, we collected symptomatic leaves of several monocotyledonous plants in the same locations and determined their viromes using small RNA high-throughput sequencing (HTS). As a result, we have identified the presence of wheat streak mosaic virus (WSMV), barley yellow striate mosaic virus (BYSMV), barley virus G (BVG), and two additional viruses, namely Aphis glycines virus 1 (ApGlV1) and Ljubljana dicistrovirus 1 (LDV1), which are described for the first time in Hungary. New hosts of the viruses were identified: Cynodon dactylon is a new host of BYSMV and LDV1, Echinocloa crus-galli is a new host of BVG, ApGlV1 and LDV1, Sorghum halepense is a new host of ApGlV1, and Panicum miliaceum is a new host of LDV1. At the same time, Zea mays is a new host of ApGlV1 and LDV1. Small RNA HTS diagnosed acute infections but failed to detect persistent ones, which could be revealed using RT-PCR. The infection rates at the different locations and plant species were different. The phylogenetic analyses of the sequenced virus variants suggest that the tested monocotyledonous weeds can host different viruses and play a virus reservoir role. Viral spread from the reservoir species relies on the activity of insect vectors, which is why their management requires an active role in plant protection strategies, which need careful planning in the changing environment.

Foxglove aphid, Aulacorthum solani Kaltenbach (Hemiptera: Aphididae), is a major pest worldwide. It can infest various crops, including soybean, and reduce yields. The use of insect-resistant cultivars can effectively manage pests. Dowling is a soybean cultivar that can control Aphis glycines through antibiosis and antixenosis. In this study, we investigated the feeding behavior of A. solani using electropenetrography (EPG), and its life-history traits using an age-stage, two-sex life table, and its settling preferences on Dowling (resistant) and Heinong 51 (HN51, susceptible) soybean cultivars. The Dowling cultivar showed strong antibiosis against A. solani. Aphids feeding on Dowling exhibited significantly reduced survival, fecundity, and longevity, and increased nymph duration. Moreover, Dowling had negative impacts on the demographic parameters of the aphids. The number of A. solani individuals was significantly less on Dowling than on HN51, indicating the antixenotic effects of Dowling. As shown using EPG, the mechanical blocking wave (F) of A. solani was significantly longer after feeding on Dowling than after feeding on HN51, indicating that Dowling has a higher mechanical resistance. In conclusion, Dowling exhibited strong resistance to A. solani. These results are beneficial for integrated pest management in soybean fields and breeding programs.

Trichogramma spp. wasps are egg parasitoids with a long history of mass rearing for augmentation biocontrol programs in field crop and orchard landscapes. Supplementary nutrition can improve the longevity, fecundity, and biocontrol efficacy of parasitoids. To improve the production efficiency and parasitism performance of Trichogramma dendrolimi Matsumura (Hymenoptera: Trichogrammatidae), the present study screened and examined the potential supplementary nutrients for this biological control agent. Dietary supplementation with a 10% sucrose solution significantly increased wasp longevity and parasitism potential of T. dendrolimi on host eggs, but provision of pollen did not provide additional benefits. Laboratory and greenhouse cage tests demonstrated that wasp access to soybean aphid Aphis glycines Matsumura (Hemiptera: Aphididae) honeydew, comprised primarily of melezitose and trehalose, improved T. dendrolimi longevity and parasitism. In conclusion, provision of a 10% sucrose solution to adult wasps will enhance the mass-rearing efficiency of T. dendrolimi; furthermore, field release of T. dendrolimi by plant vectors bearing honeydew-producing aphids holds promise for improving the biocontrol efficacy of T. dendrolimi.