Plant Pests Research Articles

Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry: An Innovative Tool for Rapid Identification of Hylurgus ligniperda, an Invasive Pest

Hylurgus ligniperda is an imported quarantine plant pest in China. Its identification is usually based on morphological characteristics; therefore, species identification needs high professional requirements of staff and professionals with high experience accumulated through long-term training. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) is a rapid identification technology, which is based on protein profiles of species. It has been widely used for the identification of pathogenic microorganisms. Many studies have reported the identification of mosquitoes, ticks, and other arthropods. The application of MALDI-TOF MS in the identification of H. ligniperda can improve the identification efficiency of H. ligniperda, preventing and control its harm and further spread. To construct a spectra database for H. ligniperda, we analyzed the effect of different factors, such as different body parts, developmental stages, populations, and preservation conditions, on its protein spectrum. We collected protein spectrum profiles from 19 specimens of H. ligniperda and its related species, obtaining 211 protein spectra to construct a reference database and validate identification. The protein spectrum from the chest specimens of H. ligniperda showed many peaks, high intensity, and a stable signal, indicating a successful data establishment. The difference in protein spectra between different regions of the same species was less, but did not affect the identification results. Clear differences were observed in the protein spectrum across many developmental stages. The database established by the adult specimens protein spectrum can accurately identify Dendroctonus valens, Tomicus piniperda, and H. ligniperda. MALDI-TOF MS technology can be used for the rapid identification of H. ligniperda. This method is rapid and direct, and the identification results are robust. It does not require specialized entomological expertise and can be used for customs interception and field investigations.

Comparative analysis of antioxidant enzyme activity and defence responses in root‐knot nematode resistant and susceptible carrot cultivars

AbstractRoot‐knot nematodes (RKNs) are one of the most serious pests of carrot plants. Resistance cultivars are a cost‐effective and ecofriendly management strategy for nematodes. To develop these, it is essential to understand the genetic, molecular and biochemical aspects underpinning RKN infection. Here, Meloidogyne javanica penetration and development, defence reactions and antioxidant enzyme activity were investigated in a resistant carrot cultivar (TN‐99‐129) compared to the susceptible cultivar TN‐99‐62. No significant difference was found in the number of J2s penetrating the roots of both cultivars. At 2 days post‐inoculation (DPI), necrosis symptoms were observed around the head of penetrated nematodes. Cell death also increased in the roots of the nematode‐infected TN‐99‐129 cultivar. Callose deposition happened at 6 DPI, and lignin content increased with delay (21 DPI) in the inoculated resistant cultivar. In addition, the reactive oxygen species metabolism process in resistant and susceptible cultivars was significantly different. In TN‐99‐129, catalase activity inhibition was observed at the early (2 DPI) phases of infection, and increasing superoxide dismutase activity and a relative decrease in catalase activity during nematode development. The activity of guaiacol peroxidase also increased significantly in the resistant cultivar, but no significant difference was observed in the activity of ascorbate peroxidase. This study explains the process of defence reactions in the TN‐99‐129 carrot cultivar during RKN penetration and development. The exhaustive characterization of the defence mechanism of a novel source of resistance to RKN in carrots constitutes a significant step toward their use in crop breeding.

Pest Status of Subfamily Lymantriinae (Lepidoptera: Erebidae: Noctuoidea): Review

Plant diseases and pests are important factors determining plant yield production, including mango. Mango fruit rot caused by insects and microbes has become a significant threat to mango production in Southeast Asia and worldwide. Insect plant pathogens affect crop yields' profitability, quality, and quantity. Some infections could occur before harvest and remain dormant until the favourable condition is achieved, and the disease will break out after harvest, reducing mango production. They act as a threat to the crops through various mechanisms of pathogenesis that compromise the immune system of the plants, such as developing any ways to attack the plants, seeking entry via open pores or exposed surface or wound, and sourcing nutrients forcefully for their growth and development. Depending on the environmental factors, the insect contracts the host through primary or secondary infection. This paper summarizes mango fruit rot disease caused by insects groups such as fruit borers (Autocharis albizonalis and Citripestis eutraphera), fruit flies (Bactrocera dorsalis), and mango seed weevils (Sternochetus mangiferae). This review will provide information about fruit rot diseases on mangoes caused by insects, the mechanism of infection, the interaction between insect damage and fungal infections, effective control methods, and related integrated pest management approaches.

Bioassay Study of Azadirachtin And Plumbagin on Pericallia ricini (Lepidoptera: Arctiidae)

In recent years, the overuse of commercially obtainable synthetic pesticides against phytophagous insects has augmented their bioaccumulation in the biosphere, foremost to increased resistance and reduced soil biodiversity. Moreover, extreme uses of insecticides enter various environmental resources as an outcome of overflow, initiating deleterious health problems to agriculturalists and consumers of agricultural products. Hence, more attention is being paid towards the expansion of substitute eco-friendly insecticides that will help in an effective pest management system and also prevent longstanding exposure that causes diseases. As a result, important ecologically friendly and harmless alternative practice strategies to artificial compounds are essential. Azadirachtin and plumbagin (phytoproducts) have been identified as an extraordinary biocontrol agent with low toxicity and high efficacy among many plant products for latent chemotherapeutic compounds in plant pest and disease management systems. The biocidal effectiveness of neem is attributed to its azadirachtin active ingredient, which affect some metabolic processes in insects such as protein synthesis, deviations in biological fitness, reduced sexual communication, and chitin synthesis. Similarly, Plumbagin (Napthaquinones) have established substantial attention in agricultural chemistry because of a novel action mode, extremely high activity against a broad spectrum of insects, low acute toxicity to mammals, and environmentally benign characteristics. The present study indicated that Azadirachtin and Plumbagin can be significant alternatives to Chemical insecticides for Pericallia ricini control in short-cycle crops.

Flowering Ocimum gratissimum intercropped in tea plantations attracts and reduces Apolygus lucorum populations.

Apolygus lucorum is one of the most important piercing-sucking insect pests of the tea plant In this study, we assessed the attractiveness of basil plants to A. lucorum and the effectiveness of Ocimum gratissimum L. in the control of A. lucorum. The control efficiency of main volatile chemicals emitted from O. gratissimum flowers was also evaluated. Among seven basil varieties, O. gratissimum was more attractive to A. lucorum adults and was selected as a trap plant to assess its attractiveness to A. lucorum and effects on natural enemies in tea plantations. The population density of A. lucorum on trap strips of O. gratissimum in tea plantations was significantly higher than that on tea at 10-20 m away from the trap strips. Intercropping O. gratissimum with tea plants, at high-density significantly reduced A. lucorum population levels. Eucalyptol, limonene, β-ocimene, and linalool were the four dominant components in the O. gratissimum flower volatiles, and their emissions showed a gradual upward trend over the sampling period. Olfactometer assays indicated that eucalyptol and dodecane showed attraction to A. lucorum. High numbers of A. lucorum were recorded on limonene, eucalyptol, and myrcene-baited yellow sticky traps in field trials in which 11 dominant volatiles emitted by O. gratissimum flowers were evaluated. Our research indicated that the aromatic plant O. gratissimum and its volatiles could attract A. lucorum and planting O. gratissimum has the potential as a pest biocontrol method to manipulate A. lucorum populations in tea plantations. © 2024 Society of Chemical Industry.

An Advancing GCT-Inception-ResNet-V3 Model for Arboreal Pest Identification

The significance of environmental considerations has been highlighted by the substantial impact of plant pests on ecosystems. Addressing the urgent demand for sophisticated pest management solutions in arboreal environments, this study leverages advanced deep learning technologies to accurately detect and classify common tree pests, such as “mole cricket”, “aphids”, and “Therioaphis maculata (Buckton)”. Through comparative analysis with the baseline model ResNet-18 model, this research not only enhances the SE-RegNetY and SE-RegNet models but also introduces innovative frameworks, including GCT-Inception-ResNet-V3, SE-Inception-ResNet-V3, and SE-Inception-RegNetY-V3 models. Notably, the GCT-Inception-ResNet-V3 model demonstrates exceptional performance, achieving a remarkable average overall accuracy of 94.59%, average kappa coefficient of 91.90%, average mAcc of 94.60%, and average mIoU of 89.80%. These results signify substantial progress over conventional methods, outperforming the baseline model’s results by margins of 9.1%, nearly 13.7%, 9.1%, and almost 15% in overall accuracy, kappa coefficient, mAcc, and mIoU, respectively. This study signifies a considerable step forward in blending sustainable agricultural practices with environmental conservation, setting new benchmarks in agricultural pest management. By enhancing the accuracy of pest identification and classification in agriculture, it lays the groundwork for more sustainable and eco-friendly pest control approaches, offering valuable contributions to the future of agricultural protection.

Insects Induced Mango Fruit Rot: Unraveling the Culprits

Plant diseases and pests are important factors determining plant yield production, including mango. Mango is an economically important fruit crop in tropical and subtropical areas. Mango fruit rot caused by insects and microbes has become a significant threat to mango production in Southeast Asia and worldwide. Insect plant pathogens affect crop yields' profitability, quality, and quantity. Some infections could occur before harvest and remain dormant until the favourable condition is achieved, and the disease will break out after harvest, reducing mango production. They act as a threat to the crops through various mechanisms of pathogenesis that compromise the immune system of the plants, such as developing any ways to attack the plants, seeking entry via open pores or exposed surface or wound, and sourcing nutrients forcefully for their growth and development. Depending on the environmental factors, the insect contracts the host through primary or secondary infection. This paper summarizes mango fruit rot disease caused by insects groups such as fruit borers (Autocharis albizonalis and Citripestis eutraphera), fruit flies (Bactrocera dorsalis), and mango seed weevils (Sternochetus mangiferae). This review will provide information about fruit rot diseases on mangoes caused by insects, the mechanism of infection, the interaction between insect damage and fungal infections, effective control methods, and related integrated pest management approaches.

An Automatic Monitoring System for Dragon Fruit Using Convolutional Neural Networks (CNN) and Internet of Things (IoT)

Plant diseases and pests have led to a decline in the quality of dragon fruit produced in Banyuwangi regency, Indonesia. Infections in dragon fruit cause rot, and farmers struggle to identify the pests responsible. To address this problem, this work proposed two concepts for the classification and monitoring systems of dragon fruit. The classification was done by processing some images of dragon fruits captured by DLSR camera and utilizes a convolutional neural network with three layers for training and testing. The monitoring system is based on the Internet of Things to tracks the status of ripe, raw, and rotten fruits. The application of the dragon fruit classification system to ripe, rotten, and raw fruits has yielded results that increase fold accuracy by 0.976, 0.981, and 0.986, respectively, with 200 training data in each of the three training and testing phases. There is a decrease of 0.024, 0.019, and 0.014 in fold loss accuracy. Meanwhile, the monitoring system's platform integrates the classification of dragon fruit to monitor the condition of ripe, raw, and rotting fruit in real time. With the implementation of the classification and monitoring system, farmers will be better equipped to predict when dragon fruit will ripen and prevent the spread of rot to other fruits.

Genetically encoded libraries and spider venoms as emerging sources for crop protective peptides.

Agricultural crops are targeted by various pathogens (fungi, bacteria, and viruses) and pests (herbivorous arthropods). Antimicrobial and insecticidal peptides are increasingly recognized as eco-friendly tools for crop protection due to their low propensity for resistance development and the fact that they are fully biodegradable. However, historical challenges have hindered their development, including poor stability, limited availability, reproducibility issues, high production costs, and unwanted toxicity. Toxicity is a primary concern because crop-protective peptides interact with various organisms of environmental and economic significance. This review focuses on the potential of genetically encoded peptide libraries like the use of two-hybrid-based methods for antimicrobial peptides identification and insecticidal spider venom peptides as two main approaches for targeting plant pathogens and pests. We discuss some key findings and challenges regarding the practical application of each strategy. We conclude that genetically encoded peptide library- and spider venom-derived crop protective peptides offer a sustainable and environmentally responsible approach for addressing modern crop protection needs in the agricultural sector.

Identifikasi Penyakit Tanaman Citra Daun Cabe Menggunakan Gray Level Co-Occurrencce Matrix Dan Support Vector Machine

Disease control of chili leaf citra plants is an important aspect in modern agriculture to increase crop yields and reduce losses due to pest attacks on chili leaf citra plants. In this research, identification of chili leaf diseases uses Gray Level Co-Occurrence to obtain image features, and the Support Vector Machine (SVM) method is used to classify the feature extraction results according to leaf disease categories in the test image. Based on the disease class using the test image. .As a classification tool for identifying plant pests in images of chili leaves, the dataset used in this research consists of images of leaves that represent normal conditions and conditions attacked by pests. The pest identification process consists of several stages, including image pre-processing, feature extraction, as well as training and testing. SVM model.

Rootstocks for Grapevines Now and into the Future: Selection of Rootstocks Based on Drought Tolerance, Soil Nutrient Availability, and Soil pH

Rootstocks are used in viticulture to manage plant pests and diseases, particularly phylloxera and root-knot nematodes, and to improve grape and wine production. A wide range of rootstocks are commercially available, making selecting the optimal rootstock a difficult decision. In particular, distinct rootstock genotypes may manifest varying degrees of tolerance or resistance to abiotic stress, necessitating meticulous consideration during the rootstock selection process. This article reviews characteristics of various commercial rootstocks, as well as rootstocks being developed in recent years. This review further discusses responses of rootstocks to drought, soil nutrients, and soil pH. This review mainly focuses on influence of rootstocks on physiology characteristics of grafted scions rather than berry yield and quality. The breadth of this review benefits both researchers and practitioners by providing comprehensive summery of rootstocks to inform selection and to guide future research.

New species of the genus <i>Calycomyza</i> Hendel (Diptera, Agromyzidae) in the South Caucasus fauna

To study the diversity of agromizids (leaf miners) in the South Caucasus, the species external morphological features, their host plants, the development of larvae and pupae and to assess the degree of crop infestation by leaf‐miners.The study was carried out within the framework of the scs 21‐002 scientific program “Leaf miners as pests of agricultural plants (Diptera: Agromyzidae): the latest control measures”. Type samples were fixed in 75 % ethyl alcohol and deposited in the Agrarian Scientific Research Laboratory of the Scientific Centre of Zoology and Hydroecology. Species were identified by examining the male genitalia. The degree of damage of the host–plant was determined based on intensity indicators.As a result of this research, a new species of the Calycomyza genus was discovered in the South Caucasus fauna. Larvae of C. jucunda (Wulp, 1867) were found on the leaves of Beta vulgaris, a host plant mentioned for the first time here. As a Nearctic species, it was also first discovered in the southern Caucasus.The study of the male genitalia indicates expansion of the biogeographical distribution of Calycomyza species, as most of them are found in the Nearctic and Neotropical regions. In terms of intensity, C. jucunda is classified as a less dangerous species for agricultural crops.

Ant communities and their trophobionts shape the incidence of pests and diseases in Indonesia’s coffee agroforestry system

Abstract. Muhammad FN, Rizali A, Rahardjo BT. 2024. Ant communities and their trophobionts shape the incidence of pests and diseases in Indonesia’s coffee agroforestry system. Biodiversitas 25: 1127-1134. Ants play various roles in a coffee agroecosystem, and their presence may impact biological control in coffee plantations. Despite the pantropical economic importance of coffee, most research is focused on the Americas. This study investigates how ant communities and their trophobionts shape the incidences of pests and diseases in the Indonesian shade coffee agroecosystem. Three 30 m x 30 m plots consisting of a total of 256 coffee plants were observed from January to March 2022. Ant communities and their trophobiont were observed using three methods: visual, tuna bait, and live bait. The ants found were classified into dominant and non-dominant based on their nesting behavior and dominance in the bait trap. Pest damage and disease intensity observation were also conducted three times. Generalized linear models were used to test the relationships between ant, hemipteran, coffee berry borer, twig borer damage and leaf rust disease intensity. Twenty-one species of ants were found, and five of them were categorized as dominant ants. Ants correlate coffee pest damage and disease intensity, their hemipteran trophobionts, or both. Dolichoderus thoracicus ant positively correlated with all trophobiont hemipteran and negatively correlated with twig borer damage. Technomyrmex albipes positively correlated with aphids but negatively with flatids. Meanwhile, Tetraponera sp.1 ant only positively correlated with flatids. In trophobiont hemipteran group, all except aphids positively correlated with coffee pests and disease. Scale insect Coccus viridis positively correlated with coffee leaf rust and twig borer infestation intensity, while flatid presence even positively correlated with all coffee plant pest and disease intensity. Indirectly, ants may reduce coffee pests and diseases through hemipteran suppression. The results suggest that the interaction of ants and their trophobiont hemipteran can act as a biological control agent for coffee pests and diseases.

Effectiveness of using different types of nuclei and methods of replanting queen bees in bags

In Ukraine, among other industries, beekeeping occupies an important place. This fact is facilitated by the developed agricultural direction of the country and the high percentage of cultivation of entomophilic crops. However, despite the broad prospects for development and transition to an industrial basis, the beekeeping industry of Ukraine is represented, in the vast majority, by relatively small farms. One of the reasons for the low development of industrial honey production in Ukraine is the high costs of organizing an industrial apiary, which include the purchase of modern equipment for quick and efficient opening of frames, special equipment for pumping honey, the construction of separate premises for the honey pumping workshop, as well as the constant updating of equipment, such as new hives and frames, and the purchase of breeding queens. Another significant problem is the death of bee colonies due to a variety of diseases, including Varroa mite infestation. The use of pesticides to combat diseases and pests of agricultural plants and forest lands contributes to its negative share. An effective and cost-effective way to expand and increase the productivity of the apiary is the formation of bee packages using high-quality breeding queens. The use of early fertile queens makes it possible to form a strong full-fledged family and make full use of the honey collection this year. The effectiveness of the use of different types of nuclei and methods of replanting fertile queen bees in the formation of bee packages was checked. The study was carried out on bees of the Ukrainian steppe breed. The best results in terms of the percentage of fertile queens and the cost of queens per fertile were obtained using a full-size nucleus for 3 standard frames in a 16-frame bed. However, the same method required a larger number (10 times) of worker bees compared to the micronucleus. With traditional replanting using the Titov cage, the share of accepted queen bees is 90 %, and the maximum rate of reception of queen bees in packages is recorded when using the fourth method of transplantation. So, when transferring a queen with a frame of printed brood and young worker bees, the relative proportion of accepted queen bees was 98 %. Therefore, the traditional method can be considered optimal in terms of indicators: reception, manufacturability, costs.

Biochemistry and transcriptomic analyses of Phthorimaeaabsoluta (Lepidoptera: Gelechiidae) response to insecticides

Phthorimaeaabsoluta is an invasive solanaceous plant pest with highly devastating effects on tomato plant. Heavy reliance on insecticide use to tackle the pest has been linked to insecticide resistance selection in P.absoluta populations. To underline insights on P.absoluta insecticide resistance mechanisms to diamides and avermectins, we evaluated the transcriptomic profile of parental (field-collected) and F8 (lab-reared) populations. Furthermore, to screen for the presence of organophosphate and pyrethroid resistance, we assessed the gene expression levels of acetylcholinesterase (ace1) and para-type voltage-gated sodium channel (VGSG) genes in the F1 to F8 lab-reared progeny of diamide and avermectin exposed P.absoluta field-collected populations. The VGSG gene showed up-regulation in 12.5% and down-regulation in 87.5% of the screened populations, while ace1 gene showed up-regulation in 37.5% and down-regulation in 62.5% of the screened populations. Gene ontology of the differentially expressed genes from both parental and eighth generations of diamide-sprayed P.absoluta populations revealed three genes involved in the metabolic detoxification of diamides in P.absoluta. Therefore, our study showed that the detoxification enzymes found could be responsible for P.absoluta diamide-based resistance, while behavioural resistance, which is stimulus-dependent, could be attributed to P.absoluta avermectin resistance.

Biological control effect of Trichoderma harzianum (Hypocreales: Hypocreaceae) against phytopathogens

AbstractChemical pesticides are synthetic substances created to manage plant pests. Frequent chemical usage causes extensive damage to crops and contributes to pest resistance, leading to environmental contamination, harm to non‐target organisms, the emergence of pesticide‐resistant species, and potential health hazards for humans. The aim of this study is to isolate, identify, and characterize biocontrol agents Trichoderma harzianum and evaluate their effects on various plant phytopathogens. T. harzianum biocontrol effects were tested against various fungal phytopathogens, including Sclerotium rolfsii, Alternaria sp., Pythium aphanidermatum, Macrophomina phaseolina, Fusarium oxysporum, Helminthosporium sativum, and Aspergillus niger. The results clearly showed that, compared to the other Trichoderma species, TVK1 demonstrated the highest ability to suppress phytopathogens, with a growth inhibition rate of 2.48 cm per day. TVK2 grows at a rate of 1.96 cm per day, whereas TVK5 grows at a rate of 1.98 cm per day. The level of antifungal volatile organic compounds produced by TVK1 spores was higher against plant pathogens compared to the other species examined. This compound inhibits the growth of plant pathogens. T. harzianum can eliminate 100% of S. rolfsii pathogens and 100% of Alternaria sp. Pathogens were reduced by 92.02% for A. niger, 94% for F. oxysporum, 100% for P. aphanidermatum, 94.07% for H. sativum, and 100% for M. phaseolina. In a detached leaf assay, TVK1 inhibited the growth of pathogens in various plant leaves, including tomato, mustard, and eggplant, when compared to both the commercially available fungicide and the control. The study confirms that the isolate TVK1 can combat various phytopathogens. Early application of T. harzianum can reduce the risk of phytopathogenic attacks on leaves and promote plant growth.

IOT- Based Smart Plant Protection and Pest Control by Using Raspberry Pi

In economies heavily dependent on agriculture, such as India, the farming sector plays a crucial role, yet it faces various challenges that hinder its profitability and, unfortunately, contribute to farmer suicides. Pest attacks stand out as a significant factor contributing to the agricultural woes, causing substantial harm to crops. This research proposes a solution leveraging Raspberry Pi technology, incorporating a mathematical model known as Beta regression analysis. The model utilizes farm humidity and temperature as inputs to predict environmental conditions conducive to pest formation and attacks. The resultant Beta regression factor serves as a risk indicator for environmental health. Based on this factor, the system forecasts the likelihood of pest occurrences. By offering advance predictions of pest activity, farmers can strategically apply the right amount of pesticides, effectively mitigating the impact of pests on their crops. This proactive approach allows farmers to manage potential damage before it occurs, fostering a more sustainable and profitable farming environment. The innovative system outlined in this paper aims to empower farmers with accurate pest control predictions, thus enhancing their ability to navigate and overcome challenges in the agricultural landscape.

Production of G0 potato seeds from in vitro cultured plantlets

Good quality seeds are needed to produce potato tubers that have high quantity and quality. Seed availability needs to be supported by propagation techniques through in vitro culture. The purpose of this technical note is to provide information regarding the production stages of G0 potato seeds from in vitro cultured plantlets. Data searches were carried out from January 23 to February 24 2023 at CV. Bumi Agro Technology, Kertawangi Village, Cisarua District, Kabupaten Bandung Barat. Data was obtained from observations, field practice, discussions and interviews, as well as literature studies. The results of the data search obtained information on the production stages of G0 potato seeds, which consist of : management of plantlets originating from the IPB PPSHB Laboratory, acclimatization, transplanting, mini cuttings, land preparation, transplanting mini cuttings, maintenance including fertilizing, watering, replanting, controlling plant pest organisms, as well as harvesting and post-harvest. The results of these stages produce G0 potato seeds which are ready to be planted to produce G1 potato tubers or used as a source of explants in in vitro culture.

The relationship between Otiorhynchus ukrainicus (Korotyaev, 1984), Otiorhynchus rotundus (Marseul, 1872) and Otiorhynchus smreczynskii (Cmoluch, 1968): a hybrid speciation reconstruction

Otiorhynchus rotundus (Marseul, 1872) and Otiorhynchus smreczynskii (Cmoluch, 1968: a hybrid speciation reconstruction. Folia Biologica (Kraków) 72: 16-28. Otiorhynchus smreczynskii (Cmoluch, 1968) is a ubiquitous weevil species. Despite being common, the species is relatively unknown and most research has focused on its role as a plant pest. In our work, we compared O. smreczynskii and the closely related Otiorhynchus rotundus (Marseul, 1872) and Otiorhynchus ukrainicus (Korotyaev, 1984) based on molecular data. This was the first time that the molecular data of O. ukrainicus has been obtained. We used mitochondrial CO1 and the nuclear markers CAS and ArgK. Based on this data, we created phylogenetic trees, calculated genetic distances and conducted species delimitation using the PTP method. We also analysed the allozymes, proving that all the studied specimens of O. smreczynskii are hybrid triploids. The lower interspecific divergence (COI: 0.49%) indicates a recent speciation event. These results show that with a high probability, O. smreczynskii originated from O. rotundus and O. ukrainicus.

Inhibition Effect of Non-Host Plant Volatile Extracts on Reproductive Behaviors in the Diamondback Moth Plutella xylostella (Linnaeus).

The pest management of Plutella xylostella, the global pest of cruciferous plants, is primarily dependent upon continued applications of insecticides, which has led to severe insecticide resistance and a series of ecological concerns. The essential oils (EOs) of non-host plants are considered to have a high application potential in pest behavioral control. In P. xylostella, the insecticidal properties, antifeeding activities, and oviposition inhibition effects of many EOs have been studied in larvae and female moths. However, less focus has been placed on the inhibitory effect on sex pheromone communication during courtship, which is vital for the reproduction of the offspring. In this study, by combining electrophysiological studies, laboratory behavioral assays, and field traps, we demonstrated that non-host plant EOs significantly inhibited the reproductive behaviors of both sexes. Notably, the calamus (Acorus gramineus) EO inhibited the preference of male moths for synthetic sex pheromone blends and reduced the egg-laying number of female moths on host plants, with the highest inhibition rates of 72% and 100%, respectively, suggesting a great application prospect of calamus and its EO on the behavioral control strategies of P. xylostella.