Transmission Of Plant Viruses Research Articles

Inhibition of Bemisia tabaci vectored, GroEL mediated transmission of tomato leaf curl New Delhi virus by garlic leaf lectin (Allium sativum leaf agglutinin)

GroEL or symbionin synthesized by the endosymbionts of whitefly (Bemisia tabaci)/ aphids play a cardinal role in the persistent, circulative transmission of plant viruses by binding to viral coat protein/ read-through protein. Allium sativum leaf agglutinin (ASAL), a Galanthus nivalis agglutinin (GNA)- related mannose-binding lectin from garlic leaf has been reported as a potent controlling agent against hemipteran insects including whitefly and aphids. GroEL related chaperonin- symbionin was previously identified as a receptor of ASAL by the present group in the brush border membrane vesicle (BBMV) of mustard aphid. In the present study similar GroEL receptor of ASAL has been identified through LC-MS/MS in the BBMV of B. tabaci which serves as a vector for several plant viruses including tomato leaf curl New Delhi virus (ToLCNDV). Ligand blot analysis of ASAL-fed B. tabaci showed that when GroEL is pre-occupied by ASAL, it completely blocks its further binding to ToLCNDV coat protein (ToLCNDV-CP). Prior feeding of ASAL hindered the co-localization of ToLCNDV-CP and GroEL in the midgut of B. tabaci. Immunoprecipitation followed by western blot with ASAL-fed B. tabaci yielded similar result. Moreover, ASAL feeding inhibited viral transmission by B. tabaci. Together, these results confirmed that the interaction of ASAL with GroEL interferes with the binding of ToLCNDV-CP and inhibits further B. tabaci mediated viral transmission.

The molecular mechanism of efficient transmission of plant viruses in variable virus–vector–plant interactions

Plant viruses are mainly transmitted by insect vectors in the non-persistent, semi-persistent, or persistent modes. In the non-persistent mode, plant viruses are retained in the stylets of their insect vectors. In the semi-persistent mode, plant viruses are carried to vector foreguts or salivary glands, but they cannot spread to salivary glands. In the persistent mode, plant viruses are retained in vector guts and can spread to salivary glands. In the non-persistent and semi-persistent modes, plant viruses are retained for a short time and cannot enter the hemolymph of insect vectors, whereas in the persistent mode, plant viruses are retained for a relatively long time and can be found in the hemolymph. Here, we reviewed recent studies that uncovered molecular mechanisms of how plant viruses manipulate host traits for efficient transmission by insect vectors. Normally, plants that are infected with viruses, regardless of the transmission mode, tend to release more attractive volatiles to vectors. However, plant defensive systems are regulated differently by viruses in these three modes. In the non-persistent mode, virus infections significantly induce plant defense responses, which probably trigger vectors (e.g., winged aphids) to disperse and transmit viruses in a short time. In the semi-persistent mode, virus infections frequently suppress plant defense responses, resulting in an increase of vector population and facilitating viral transmissions during vector outbreaks. In the persistent mode, virus infections reduce plant defense responses and manipulate plant traits to become suitable feeding sites in a relatively long period of time. Understanding the underlying mechanisms of virus–vector–plant interactions will lay a foundation for preventing virus transmission.

Exploring species composition and population dynamics of thrips (Thysanoptera: Thripidae) in peanut crops in Argentina

Thrips (Thysanoptera: Thripidae) are major pests of peanut (Arachis hypogaea L.). They cause feeding damage and indirect injuries transmitting plant viruses. In Argentina, peanut is commonly affected by thrips. The crop also is infected by groundnut ringspot orthotospovirus, a virus transmitted by thrips vectors. However, in the country, information about thrips in peanut is very scarce. A 3-yr study was conducted to characterize the species composition and thrips population dynamics in the main peanut-producing area in Argentina. Frankliniella schultzei (Trybom), followed by Caliothrips phaseoli (Hood) were the most abundant species. Together the two species accounted for ~ 95-99 % of the total adult thrips captured in each season. Significant different abundances were observed among these two thrips species throughout each peanut growing season. Nevertheless, the temporal dynamics of F. schultzei and C. phaseoli showed a similar trend in the three study years. In general, the colonization by F. schultzei started in late December and their population increased from the second half of January peaking around the first half of February. The highest densities of F. schultzei occurred simultaneously in foliage and flowers during the warmer months of the year. The C. phaseoli population inhabited on foliage and peaked in late February or mid-March. Other species collected were Frankliniella occidentalis (Pergande), Frankliniella gemina Bagnall, and Thrips tabaci (Lindeman). This study mentions F. gemina in peanut for the first time. Results show that F. schultzei and C. phaseoli are common thrips pests in peanut in Argentina and provide new information about the population dynamics of these thrips species in peanut crops.

Whitefly Network Analysis Reveals Gene Modules Involved in Host Plant Selection, Development and Evolution.

Whiteflies are Hemipterans that typically feed on the undersides of plant leaves. They cause severe damage by direct feeding as well as transmitting plant viruses to a wide range of plants. However, it remains largely unknown which genes play a key role in development and host selection. In this study, weighted gene co-expression network analysis was applied to construct gene co-expression networks in whitefly. Nineteen gene co-expression modules were detected from 15560 expressed genes of whitefly. Combined with the transcriptome data of salivary glands and midgut, we identified three gene co-expression modules related to host plant selection. These three modules contain genes related to host-plant recognition, such as detoxification genes, chemosensory genes and some salivary gland-associated genes. Results of Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses elucidated the following pathways involved in these modules: lysosome, metabolic and detoxification pathways. The modules related to the development contain two co-expression modules; moreover, the genes were annotated to the development of chitin-based cuticle. This analysis provides a basis for future functional analysis of genes involved in host-plant recognition.

Mutation (G275E) of nAChR subunit Foα6 associated with spinetoram resistance in Australian western flower thrips, Frankliniella occidentalis (Pergande).

Western flower thrips, Frankliniella occidentalis is an economically important agricultural pest. It causes damage by feeding and oviposition or indirectly by plant virus transmission. Australian F. occidentalis are resistant to many insecticides including spinosad and the related chemical spinetoram. Spinetoram resistance to F. occidentalis has been recently reported in three different Australian States, however, mechanisms conferring that resistance have not been investigated. To identify the mechanisms underlying resistance to spinetoram in F. occidentalis, we sequenced the genomic region of nicotinic acetylcholine receptor Foα6 in number of spinosad and spinetoram resistant field-populations. We found that a single nucleotide substitution (G to A) in exon 9 of the α6 subunit was present in resistant strains (G275E) and absent from susceptible. By examining field populations we consider the G275E mutation is the major cause of resistance to spinetoram in Australian F. occidentalis. We developed a real-time PCR diagnostic assay to quickly identify resistant alleles in field-populations. The method was used to test spinetoram resistant F. occidentalis collected from Australian cotton during the 2018-2019. Results show thrips tested carried the G275E mutation and the resistance allele was unusually widely distributed. The wide distribution of G275E mutation was not expected because spinetoram is not extensively used in Australian cotton. We speculate resistance may relate to extensive chemical use in crops nearby such as horticulture where thrips are often targeted for control. Our molecular diagnostic assay can provide timely and precise resistance frequency information that can support sustainable chemical use including spinetoram based IPM.

Ultra structural study on different sensory structure and some associated body parts of mango mealy bug, Drosicha mangiferae (G.) by scanning electron microscopy

Ultra structural study on different sensory structure and some associated body parts of mango mealy bug, Drosicha mangiferae (G.) by scanning electron microscopy

Tomato Chlorosis Virus Infection Facilitates Bemisia tabaci MED Reproduction by Elevating Vitellogenin Expression.

Simple SummaryThe sweet potato whitefly, Bemisia tabaci, is a polyphagous, global invasive insect pest. It can damage vegetables and crops directly by feeding and indirectly by transmitting plant viruses. Previously, we showed that virus infection of host plants can promote B. tabaci MED (Q biotype) reproduction. Here, using a whitefly-tomato chlorosis virus (ToCV)-tomato system, we investigated how ToCV modulates B. tabaci reproduction to facilitate its spread. ToCV infection significantly increased whitefly fecundity and the relative expression of vitellogenin gene (Vg). Both ovarian development and fecundity of whitefly were suppressed when Vg expression was silenced with or without ToCV infection. These combined results reveal that ToCV infection increases B. tabaci MED fecundity via elevated vitellogenin gene expression.Transmission of plant pathogenic viruses mostly relies on insect vectors. Plant virus could enhance its transmission by modulating the vector. Previously, we showed that feeding on virus infected plants can promote the reproduction of the sweet potato whitefly, Bemisia tabaci MED (Q biotype). In this study, using a whitefly-Tomato chlorosis virus (ToCV)-tomato system, we investigated how ToCV modulates B. tabaci MED reproduction to facilitate its spread. Here, we hypothesized that ToCV-infected tomato plants would increase B. tabaci MED fecundity via elevated vitellogenin (Vg) gene expression. As a result, fecundity and the relative expression of B. tabaci MED Vg was measured on ToCV-infected and uninfected tomato plants on days 4, 8, 12, 16, 20 and 24. The role of Vg on B. tabaci MED reproduction was examined in the presence and absence of ToCV using dietary RNAi. ToCV infection significantly increased B. tabaci MED fecundity on days 12, 16 and 20, and elevated Vg expression on days 8, 12 and 16. Both ovarian development and fecundity of B. tabaci MED were suppressed when Vg was silenced with or without ToCV infection. These combined results suggest that ToCV infection increases B. tabaci MED fecundity via elevated Vg expression.

Vine mealybugs disrupt biomass allocation in grapevine

Vine mealybug Planococcus ficus Signoret (Hemiptera: Pseudococcidae) is an important phloem-feeding pest species in many grapevine producing areas worldwide. The economic damage of P. ficus is thought to be mainly caused by sooty mould on infested grape clusters and transmission of plant viruses. Direct damage caused by mealybug feeding to grapevine plants (Vitis vinifera, L.) has only been vaguely described or otherwise completely discarded. The present study is the first to give an insight into the direct impacts of P. ficus on vegetative growth and biomass dynamics of grapevine plants. In a screenhouse, three-year-old, potted grapevine plants were infested with mealybugs at two different densities, imitating high and low field infestation levels. Mealybug numbers, plant biomass, leaf area, leaf size and leaf number were monitored over six months and compared to a control treatment without mealybugs. High infestation levels reduced leaf and stem biomass by one third, while low levels of P. ficus impacted only stem biomass, indicating a higher sensibility of the perennial parts of the plant or a reallocation of biomass. Leaf area, size and number were not affected by mealybug feeding.In conclusion, grapevine response to P. ficus is gradual and involves different plant parts depending on the severity of the attack. Contrary to previous assumptions, this study demonstrates considerable direct impacts of mealybug feeding on temporal and perennial parts of grapevine plants.

Semiochemicals for Thrips and Their Use in Pest Management.

Thrips (Thysanoptera) are small insects that can cause huge problems in agriculture, horticulture, and forestry through feeding and the transmission of plant viruses. They produce a rich chemical diversity of pheromones and allomones and also respond to a broad range of semiochemicals from plants. These semiochemicals offer many opportunities to develop new approaches to pest management. Aggregation pheromones and plant-derived semiochemicals are already available in commercial products. We review these semiochemicals and consider how we can move away from using them mainly for monitoring to using them for control. We still know very little about the behavioral responses of thrips to semiochemicals, and we show that research in this area is needed to improve the use of semiochemicals in pest management. We also propose that thrips should be used as a model system for semiochemically mediated behaviors of small insects that have limited ability to fly upwind.

Enhancing Capsid Proteins Capacity in Plant Virus-Vector Interactions and Virus Transmission.

Vector transmission of plant viruses is basically of two types that depend on the virus helper component proteins or the capsid proteins. A number of plant viruses belonging to disparate groups have developed unusual capsid proteins providing for interactions with the vector. Thus, cauliflower mosaic virus, a plant pararetrovirus, employs a virion associated p3 protein, the major capsid protein, and a helper component for the semi-persistent transmission by aphids. Benyviruses encode a capsid protein readthrough domain (CP-RTD) located at one end of the rod-like helical particle, which serves for the virus transmission by soil fungal zoospores. Likewise, the CP-RTD, being a minor component of the luteovirus icosahedral virions, provides for persistent, circulative aphid transmission. Closteroviruses encode several CPs and virion-associated proteins that form the filamentous helical particles and mediate transmission by aphid, whitefly, or mealybug vectors. The variable strategies of transmission and evolutionary ‘inventions’ of the unusual capsid proteins of plant RNA viruses are discussed.

Suitability of five plant species extracts for their compatibility with indigenous Beauveria bassiana against Aphis gossypii Glov. (Hemiptera: Aphididae)

BackgroundThe cotton aphid, Aphis gossypii Glov. (Hemiptera: Aphididae), is a major insect pest on a wide range of plants that causes high damage and transmits plant viruses. This study was carried out to evaluate an indigenous isolate, Beauveria bassiana (Bb), and extracts of 5 plant species: Psiadia penninervia, Pulicaria crispa, Euryops arabicus, Salvia officinalis, and Ochradenus baccatus against A. gossypii, as individual and combined treatments to estimate their compatibility under laboratory conditions. Also, the antifungal activity of these plant extracts against B. bassiana was evaluated.ResultsLC50 value was 8.64 × 104 spores/ml of Bb against A. gossypii, while LC50 values of the tested 5 plant extracts on A. gossypii were 103.64, 879.92, 747.90, 783.28, and 262.42 μg/ml for P. penninervia, P. crispa, E. arabicus, S. officinalis, and O. baccatus, respectively. Both P. penninervia and O. baccatus extracts had the highest antifungal activities against Bb and were significantly different from the other 3 plant extracts. After 24 h of treatment with the combination of Bb and each extract, no effect for these combinations on A. gossypii mortality was recorded. Meanwhile, 5 days after treatment, the combined treatments between Bb and each plant extract achieved a significant increase in mortality than that of the single treatment with Bb or plant extract, except for P. penninervia extract, which did not achieve a significant mortality increase when combined with B. bassiana than that of its single treatment.ConclusionP. penninervia extract was not compatible with B. bassiana, but the other tested 4 plant extracts were compatible with B. bassiana. These 4 plant extracts could be used to control aphids in combinations with B. bassiana. Further laboratory and field investigations are needed to examine the effects of these plant extracts on other insect pests or associated beneficial insects.

Biological control of silverleaf whitefly Bemisia tabaci (Hemiptera: Aleyrodidae) using predatory bugs, Dicyphus hesperus (Hemiptera: Miridae) and Orius insidiosus (Hemiptera: Anthocoridae)

The silverleaf whitefly (SLW), Bemisia tabaci, is an exotic pest that causes sporadic crop damage in Canadian greenhouses, mainly on tomatoes. Its plant feeding is responsible for both direct damage as well as the transmission of plant viruses. Interestingly, omnivorous predators, which are used as biological control agents for multiple whitefly species, can establish on greenhouse crops even before the pest has established, using alternative food resources and host plants to support the predator. However, the efficiency of such indigenous omnivorous biological agents in the suppression of high density and intense SLW infestations remains unknown. This research aimed to assess the potential of two indigenous omnivorous biological agents, Dicyphus hesperus and Orius insidiosus to control SLW infestations and their effects on tomato plant health and yield at both early stages of the crop cycle, and at high pest densities. This study showed that populations of B. tabaci are able to grow rapidly. However, neither of the introduced densities of B. tabaci nor the infestation time had a significant effect on the incidence of tomato irregular ripening disorder (TIR) and yield. Our results also show that the introduction of three or five D. hesperus adults per cage reduces the number of B. tabaci larvae and pseudo-nymphs, while O. insidiosus did not significantly reduce SLW populations. Our results suggest that D. hesperus could control high levels of SWL and at an early stage in the cropping cycle.

Flexible spandrels of the global plant virome: Proteomic-wide evolutionary patterns of structural intrinsic protein disorder elucidate modulation at the functional virus-host interplay.

Intrinsically disordered proteins and regions (IDPs/IDRs) make up a large part of viral proteomes, but their real prevalence across the global plant virome is still murky, partly because of their massive diversity. Here, we propose an evolutionary quantitative proteomic approach to foray into genomic signatures that are preserved in the amino acid sequences of orthologous IDRs. Markedly, we found that relatively abundant IDP varies substantially in viral species among and within plant virus families, including according to genome size, partition or replication strategies. We also demonstrate that most encoded proteomic modules of the plant virome contain multiple disordered features that are phylogenomically preserved, and can be correlated to genomic, bio-physical and evolutionary strategies. Furthermore, our focused interactome-wide analysis highlights lines of evidence indicating that various IDPs with similar evolutionary signatures modulate viral multifunctionality. Moreover, estimated fractions of IDR in the vicinity of pivotal evolutionary structural domains embedded in interaction modules are strongly enriched with affinity binding functional annotations and relate to vector-borne virus transmission modes. Importantly, molecular recognition features (MoRFs) are abundantly widespread in IDRs of viral hallmark modules and their binding partners. Finally, we propose a coarse-grained conceptual framework in which evolutionary proteome-wide IDP/IDRs patterns can be, rather, reliably exploited to elucidate their foundational fine-tuning role in plant virus transmission mechanisms. While opening unexplored avenues for consistently predicting virus-host functions for many new or uncharacterized viruses based on their proteomic repertoire, other considerations advocating further structural IDP research in Plant Virology are thoroughly discussed in light of viral modular evolution.

Tomato Brown Rugose Fruit Virus (ToBRFV): A Potential Threat for Tomato Production in Florida

Tobamoviruses are mechanically transmitted plant viruses that cause severe economic damage to vegetable and ornamental crops in Florida and worldwide. While certain tomato cultivars have genetic resistance to the most common tobamoviruses, no commercial tomato cultivars are resistant to tomato brown rugose fruit virus (ToBRFV), a recently described tobamovirus that also infects pepper and eggplant. It is currently unknown how ToBRFV may affect tomato production in Florida. This new 5-page publication of the UF/IFAS Plant Pathology Department describes symptoms of the virus, how it is different from other tobamoviruses, and how it is transmitted, as well as what to do if you think you have ToBRFV in your field. Written by Ozgur Batuman, Salih Yilmaz, Pamela Roberts, Eugene McAvoy, Samuel Hutton, Kishore Dey, and Scott Adkins.https://edis.ifas.ufl.edu/pp360

Wolbachia

Ary Hoffman introduces Wolbachia.

Detection of Plant Pathogenic Viruses in Commercial Gochujang (Fermented Red Pepper Paste) from Korea.

The potential transmission of plant pathogenic viruses through processed foods could be a source of concern for global crop production; however, there is a lack of supporting evidence. The present study was conducted to investigate the presence of plant pathogenic viruses in five samples of gochujang (fermented red pepper paste) manufactured in Korea. Several viruses infecting pepper were detected by reverse transcriptionpolymerase chain reaction, among which the pepper mild mottle virus (PMMoV) was detected in all five samples, at concentrations ranging from 2.8 to 7.0 (log10 copies/ml). In addition, PMMoV was observed by transmission electron microscopy in all five samples. The samples exhibited viral pathogenicity to Nicotiana benthamiana plants, indicating that global trade of processed products could be a possible source of the transmission of plant viruses.

Host plant selection and virus transmission by Rhopalosiphum maidis are conditioned by potyvirus infection in Sorghum bicolor

Many plant viruses are significant pathogens that are able to utilize arthropod vectors to infect a vast range of host plants, resulting in serious economic damage to world food crops. One such crop is Sorghum bicolor, grain sorghum, which is the fifth most important global cereal crop, it is grown for human consumption, animal feed, and biofuel. In this study, the Potyviruses Johnsongrass mosaic virus (JGMV), Maize dwarf mosaic virus (MDMV), Sugarcane mosaic virus (SCMV), and Sorghum mosaic virus (SRMV) were tested for their rates of transmission into tissues of S. bicolor by the corn leaf aphid, Rhopalosiphum maidis. In addition, virus infected and non-infected S. bicolor plants were assessed for their effects on R. maidis host plant selection behavior. Further, the propagation of each virus (viral ssRNA copy number) in infected plants was determined using qPCR amplification of viral coating protein gene fragments. The mean rate of JGMV transmission into S. bicolor plants by R. maidis was significantly lower than transmission of MDMV, SCMV, and/or SRMV. Sorghum bicolor plants infected with MDMV, SCMV or SRMV also attract significantly more R. maidis than non-infected plants. JGMV-infected plants do not effect a similar change in R. maidis plant choice preference. The preference of non-viruliferous R. maidis toward S. bicolor plants infected with MDMV, SCMV or SRMV, and lack of such attraction by JGMV-infected plants may play a role in virus transmission strategy and efficiency by the vector.

Apoptosis in a Whitefly Vector Activated by a Begomovirus Enhances Viral Transmission.

Apoptosis is generally considered the first line of defense against viral infection. However, the role of apoptosis in the interactions between plant viruses and their insect vectors has rarely been investigated. By studying plant DNA viruses of the genus Begomovirus within the family Geminiviridae, which are transmitted by whiteflies of the Bemisia tabaci species complex in a persistent manner, we revealed that virus-induced apoptosis in insect vectors can facilitate viral accumulation and transmission. We found that infection with tomato yellow leaf curl virus activated the apoptosis pathway in B. tabaci Suppressing apoptosis by inhibitors or silencing caspase-3 significantly reduced viral accumulation, while the activation of apoptosis increased viral accumulation in vivo Moreover, the positive effect of whitefly apoptosis on virus accumulation and transmission was not due to its cross talk with the autophagy pathway that suppresses begomovirus infection in whiteflies. We further showed that viral replication, rather than the viral coat protein, is likely the critical factor in the activation of apoptosis by the virus. These novel findings indicate that similarly to many animal and a few plant RNA viruses, plant DNA viruses may activate apoptosis in their insect vectors leading to enhanced viral accumulation and transmission.IMPORTANCE Of the approximately 1,100 known plant viruses, about one-third are DNA viruses that are vectored by insects. Plant virus infections often induce cellular and molecular responses in their insect vectors, which can, in many cases, affect the spread of viruses. However, the mechanisms underlying vector responses that affect virus accumulation and transmission are poorly understood. Here, we examined the role of virus-induced apoptosis in the transmission of begomoviruses, a group of single-stranded plant DNA viruses that are transmitted by whiteflies and cause extensive damage to many crops worldwide. We demonstrated that virus infection can induce apoptosis in the insect vector conferring protection to the virions from degradation, leading to enhanced viral accumulation and transmission to host plants. Our findings provide valuable clues for designing new strategies to block the transmission of insect-vectored plant viruses, particularly plant DNA viruses.

Insect Transmission of Plant Single-Stranded DNA Viruses.

Of the approximately 1,200 plant virus species that have been described to date, nearly one-third are single-stranded DNA (ssDNA) viruses, and all are transmitted by insect vectors. However, most studies of vector transmission of plant viruses have focused on RNA viruses. All known plant ssDNA viruses belong to two economically important families, Geminiviridae and Nanoviridae, and in recent years, there have been increased efforts to understand whether they have evolved similar relationships with their respective insect vectors. This review describes the current understanding of ssDNA virus-vector interactions, including how these viruses cross insect vector cellular barriers, the responses of vectors to virus circulation, the possible existence of viral replication within insect vectors, and the three-way virus-vector-plant interactions. Despite recent breakthroughs in our understanding of these viruses, many aspects of plant ssDNA virus transmission remain elusive. More effort is needed to identify insect proteins that mediate the transmission of plant ssDNA viruses and to understand the complex virus-insect-plant three-way interactions in the field during natural infection.

Development of lady beetle attractants from floral volatiles and other semiochemicals for the biological control of aphids

Abstract Aphids are among the most destructive phytophagous pests of host plants, because of their rapid reproduction, parthenogenesis, extensive crop damage, and the transmission of many plant viruses. Since lady beetles are important predatory natural enemies of aphids, developing lady beetle attractants to increase their field abundance is vital for aphid control. Floral volatiles and other semiochemicals are reportedly attractive to lady beetles. In this research, a total of 58 floral volatiles were tested by Y-tube olfactometer assays, among which 29 were highly attractive to both Harmonia axyridis (Coleoptera: Coccinellidae) and Coccinella septempunctata (Coleoptera: Coccinellidae). Meanwhile, the results of wind tunnel trials showed that only isoamyl acetate, α-humulene, trans-3-hexen-1-ol, methyl salicylate, and β-pinene lure these two species. Thereafter, 15 semiochemicals from pests, natural enemies, and pest-infested crops were mixed with the selected floral volatiles, to determine optimum formulations for attracting lady beetles through wind tunnels and further field trials. Eventually, formulas (1) α-humulene: β-pinene: methyl salicylate: trans-3-hexen-1-ol = 1:3:3:10; (5) α-humulene: β-pinene: methyl salicylate:1-nonanal = 1:3:3:10; (8) α-humulene: β-pinene: methyl salicylate: indole = 1:3:3:10 (1, 5, and 8 are labels used for the various formulations in field trials) were successfully verified to be attractive to lady beetles in both pumpkin and wheat fields. These formulations will be of great significance in developing integrated pest management strategies for aphid control.