Agricultural Pests Research Articles

Amino acids promote the rejuvenation of degenerated Metarhizium anisopliae

Metarhizium anisopliae, an entomopathogenic fungus widely employed in agricultural and forestry pest control, faces challenges related to colony growth degradation and sporulation decline during industrial production and germplasm preservation. In this study, liquid chromatography-mass spectrometry (LC-MS) was used to detect the metabolomics of the normal strain and degenerated strain, enabling a comparison and analysis of their metabolic profiles. The results revealed significant differences in metabolic phenotypes among different strains of M.anisopliae, with amino acids playing a crucial role in spore production. Through single factor and response surface tests, optimal amino acid concentrations for sporulation media were determined as follows: lysine at 25.00 mg/L, β-alanine at 140.00 mg/L, arginine at 22.5 mg/L, glutamic acid at 155.00 mg/L. Cultivating degenerated M.anisopliae using this optimized amino acid medium resulted in approximately fivefold increase in sporulation without significantly affecting LT50 values; thus indicating that the formulation promotes M.anisopliae’s sporulation without compromising its virulence.

Entomopathogenic nematode detection and counting model developed based on A-star algorithm

Entomopathogenic nematodes are soil-dwelling living organisms widely employed in the biological control of agricultural insect pests, serving as a significant alternative to pesticides. In laboratory procedures, the counting process remains the most common, labor-intensive, time-consuming, and approximate aspect of studies related to entomopathogenic nematodes. In this context, a novel method has been proposed for the detection and quantification of Steinernema feltiae isolate using computer vision on microscope images. The proposed method involves two primary algorithmic steps: framing and isolation. Compared to YOLO-V5m, YOLO-V7m, and YOLO-V8m, the A-star-based developed network demonstrates significantly improved detection accuracy compared to other networks. The novel method is particularly effective in facilitating the detection of overlapping nematodes. The developed algorithm excludes processes that increase space and time complexity, such as the weight document, which contains the learned parameters of the deep learning model, model integration, and prediction time, resulting in more efficient operation. The results indicate the feasibility of the proposed method for detecting and counting entomopathogenic nematodes.

Heavy metal exposure reduces larval gut microbiota diversity of the rice striped stem borer, Chilo suppressalis.

Cadmium (Cd), a widely distributed environmental pollutant in agroecosystems, causes negative effects on crops and herbivores through bottom-up processes. The gut microbial community of an insect can play a critical role in response to metal stress. To understand how microbiota affect the stress responses of organisms to heavy metals in agroecosystems, we initially used 16S rRNA sequencing to characterize the larval gut microbiota of Chilo suppressalis, an important agricultural pest, exposed to a diet containing Cd. The species richness, diversity, and composition of the gut microbial community was then analyzed. Results revealed that while the richness (Chao1 and ACE) of gut microbiota in larvae exposed to Cd was not significantly affected, diversity (Shannon and Simpson) was reduced due to changes in species distribution and relative abundance. Overall, the most abundant genus was Enterococcus, while the abundance of the genera Micrococcaceae and Faecalibaculum in the control significantly superior to that in Cd-exposed pests. Phylogenetic investigation of microbial communities by the reconstruction of unobserved states (PICRUSt) showed that the intestinal microorganisms appear to participate in 34 pathways, especially those used in environmental information processing and the metabolism of the organism. This study suggests that the gut microbiota of C. suppressalis are significantly impacted by Cd exposure and highlights the importance of the gut microbiome in host stress responses and negative effects of Cd pollution in agroecosystems.

Experimental evidence of negative agricultural impacts and effectiveness of mitigation strategies of invasive green iguanas (Iguana iguana) in Puerto Rico

Losses in crop yield due to invasive insects, weeds, pathogens, and herbivores cost trillions of dollars per year globally. To prevent further spread of invasive agricultural pest species, continuous monitoring and prevention are crucial. Once introduced, however, assessing the impact of an invasive pest on agricultural production and testing management strategies are essential. The green iguana (Iguana iguana), a globally widespread invasive herbivore, is considered a possible agricultural pest although no quantitative data on its impact are available. In this study, we evaluated the impact of the invasive green iguana on cucumber (Cucumis sativus, var. Dasher II) and lettuce (Lactuca sativa, var. Black-seeded Simpson) yield by testing the efficacy of two management strategies – Neem-based pesticide and mesh fencing – compared to open field cultivation in Puerto Rico. Mesh fencing led to 20% more growth and doubled cucumber yield compared to open field cultivation, while spraying Neem led to an 18% increase in plant growth but no effect on cucumber yield. We found no difference in lettuce growth or yield among treatment and control plots. This study supports categorizing the green iguana as an invasive agricultural pest species and demonstrates the reptile’s potential to reduce crop yield. It also shows that Neem application at the manufacturer’s suggested concentration is not an effective mitigation technique for reducing crop loss due to green iguana herbivory. Government agencies in regions where the green iguana has the potential to be introduced should consider the species a threat to food production when developing monitoring programs and drafting regulations.

Identification and functional study of Fib-L, a major silk fibroin gene component in rice leaf folders.

The rice leaf folder, Cnaphalocrocis medinalis (Lepidoptera: Pyralidae), is a major migratory pest in rice agriculture. This pest is characterised by its larvae's ability to fold rice leaves using silk, a behaviour that culminates in the formation of a silken cocoon during the pupal stage. The fibroin light chain (CmFib-L) gene is crucial for silk production, yet its specific function in C. medinalis has reminded elusive. This study presents a comprehensive analysis of the CmFib-L gene, revealing its complete open reading frame (ORF) and expression patterns. Notably, the gene is highly expressed in the fifth-instar larvae and the silk gland, which are critical stages for silk production. Our experiments demonstrate that silencing the CmFib-L gene leads to a reduction in pupal weight, an extension of the pupal stage and a disorganised silk cocoon. Furthermore, the larval behaviour of leaf folding and spinning is significantly impaired when the expression of CmFib-L is downregulated. These findings not only show the importance of fibroin light chain in silk production but also reveal a new target gene to regulate and control the behaviour and development of C. medinalis.

RNA interference protocols for gene silencing in the spittlebug Philaenus spumarius, vector of Xylella fastidiosa

RNA interference (RNAi) is double stranded RNA (dsRNA)-based gene silencing mechanism. Exogenous dsRNAs application to crops has raised as a powerful tool to control agricultural pests. In particular, several sap-feeder are important plant pathogens vectors, such as Philaenus spumarius, known as main vector of Xylella fastidiosa (Xf), causal agent of olive quick decline syndrome (OQDS) in southern Italy. Here, dsATP synthase beta (dsATP), dsLaccase (dsLacc) and dsGreen Fluorescent Protein (dsGFP) as control, were provided to spittlebug adults by microinjection or to nymphs fed on dsRNA-treated plant shoots. Treated insects were collected at different time points to monitor silencing efficiency over time, describing significant reduction of transcript levels from 8 to 24 days post treatment. Downregulation of target genes ranged from 2- to 16-fold compared to the corresponding dsGFP controls, where highest silencing effects were generally noticed for ATP synthase beta. Sequencing of libraries obtained from total smallRNA (sRNA) showed the generation of dsRNA-derived sRNAs by RNAi pathway, with majority of reads mapping exclusively on the correspondent dsRNA. Also, we characterized components of a functional RNAi machinery in P. spumarius. Further research is needed to clarify such mechanism, screen effective target lethal genes to reduce vector population and improve delivery strategies.

Short‐Term Grasslands in Agriculture Support Both Natural Enemy and Phytophagous Arthropod Populations

ABSTRACTSimplified agricultural land with high chemical input is increasingly replacing natural habitats in many parts of the world. This loss and fragmentation of natural areas may have profound impacts on an array of wildlife, including predatory arthropods that provide natural biocontrol of agricultural pests. There is increasing interest in utilising short‐term seminatural habitat restoration in agricultural systems to support populations of beneficial organisms. We assessed the impact of two types of short‐term set‐asides on the diversity and abundance/activity density of phytophagous and predatory arthropods. We found that flower‐enhanced set‐asides supported higher abundances of both phytophagous and predatory arthropods compared to control crop fields. In addition, we found that both set‐aside types (flower enhanced and traditional) supported a more active and diverse community of beneficial predatory carabid beetles, with particularly strong trends in set‐asides supplemented with flowering plants. These results suggest that small‐scale, temporary, seminatural habitats in agricultural systems provide support for a diverse and abundant community of both beneficial and phytophagous arthropods.

Molecular interactions of Trichoderma: from microbial competition to soil health promotion

The increasing demand for sustainable solutions to agricultural pest and disease management has positioned Trichoderma fungi as a promising biological control agent. Trichoderma is not only capable of suppressing various plant pathogens but also promotes plant growth and strengthens natural plant defenses. This mini-review explores the molecular mechanisms underlying Trichoderma's ability to function as a biocontrol agent, focusing on nutrient competition, antibiotic production, mycoparasitism, and the induction of plant resistance. Additionally, advances in genomics and transcriptomics have facilitated a deeper understanding of the signaling pathways and genes responsible for Trichoderma's biocontrol effectiveness, including G-protein and MAPK pathways. Beyond pathogen suppression, Trichoderma plays a key role in enhancing soil health and establishing symbiotic relationships with plants, contributing to improved nutrient absorption and growth hormone production. However, challenges remain in translating laboratory success to large-scale field applications. This mini review highlights the need for further research on optimizing Trichoderma formulations, understanding its interaction with other beneficial soil organisms, and exploring genetic engineering to enhance its biocontrol capabilities. The future of Trichoderma lies in its integration into holistic, agroecological systems alongside other sustainable pest management strategies.

The hindgut microbiota of coconut rhinoceros beetles (Oryctes rhinoceros) in relation to their geographical populations.

The coconut rhinoceros beetle (CRB, Oryctes rhinoceros) is a palm tree pest capable of rapidly expanding its population in new territories. Previous studies identified a digestive symbiosis between CRB and its gut microbes. However, no research compared the genetic variation of CRBs with their hindgut microbiota on a global scale. This study aims to investigate the genetic divergence of CRB and the compositional variation of CRB's microbiota across different geographical locations, and explore the association between them and their predicted functional profiles and environmental data. The research reveals a distinct and consistent microbial community within local populations, but it varies across different geographical populations. The microbial functional profiles linked to the production of digestive enzymes, including cellulases and ligninases, are nonetheless globally conserved. This suggests that CRBs employ specific mechanisms to select and maintain microbes with functional benefits, contributing to host adaptability, stress tolerance, and fitness. The CRB microbial communities did not appear to recapitulate the genetic variation of their hosts. Rather than depend on obligate symbionts, CRBs seem to establish similar digestive associations with whatever environmentally acquired microbes are available wherever they are, aiding them in successfully establishing after invading a new location.IMPORTANCECoconut rhinoceros beetles (CRBs) are notorious pests on Arecaceae plants, posing destructive threats to countries highly reliant on coconut, oil palm, and date palm as economic crops. In the last century, CRBs have rapidly expanded their presence to territories that were once free of these beetles. The United States, for instance, has officially designated CRBs as invasive and alien pests. Given their remarkable ability to swiftly adapt to new environments, their gut microbes may play a crucial role in this process. While the microbiota of CRBs vary depending on geographical location, these beetles consistently exhibit a functionally identical digestive association with locally acquired microbes. This underscores the significance of CRB-microbe association in shaping the adaptive strategies of this agricultural pest.

Production of chitinase in elicited tomato cell suspensions and its application as a biopesticide and fungicide against soil-borne pests and fungi

Soil-borne fungi and pests present significant challenges to crop production, causing diseases and reducing yields. This study explores the potential of producing chitinase from tomato cell suspension cultures and its application in controlling soil-borne fungi and pests. Tomato cell suspension cultures were established from seeds, and different elicitors—including chitin, fungal debris, and fungal metabolites—were used to optimize chitinase production. The enzyme was purified, and its physicochemical properties were characterized. Its antifungal activity was tested against various soil-borne fungi, while termiticidal activity was evaluated using four bioassay methods. Additionally, the nematicidal activity of chitinase was assessed against different stages of root-knot nematodes. Results indicated that chitin media induced the highest chitinase production and cell growth compared to other elicitors. The purified chitinase had a molecular weight of 34 kDa, with a maximum velocity (Vmax) of 0.940 μg NAG/min and a Michaelis constant of 1.236 mg colloidal chitin/mL. The turnover number (Kcat) was 1.598 μg NAG/min/mol chitinase. The enzyme exhibited a broad range of activity and stability across varying pH levels and temperatures, as well as remarkable stability under different storage times and in the presence of metal ions. Tomato-derived chitinase demonstrated superior antifungal, nematicidal, and termiticidal activities compared to common chemical fungicides and pesticides. Chitinase was successfully produced from tomato cell suspension culture in this study, highlighting its potential as a biocontrol agent for sustainable pest and disease management in agriculture.

Combating Spodoptera frugiperda (Lepidoptera: Noctuidae) with Moringa-Synthesized Silica Nanoparticles and Its Combination with Some Insecticides.

The fall armyworm (FAW), Spodoptera frugiperda (J. E. Smith), is a major agricultural pest known for developing resistance to insecticides. This study investigated a novel approach to manage FAW by silica nanoparticles (SiNPs) synthesized from eco-friendly leaf extract of Moringa oleifera Lam. (Moringaceae). This green synthesis method offers a sustainable and potentially safer alternative to traditional chemical processes. SiNP formation was confirmed by various techniques: UV-visible spectrophotometer, X-ray spectroscopy with energy-dispersive (EDX), scanning electron microscopy (SEM), and dynamic light scattering (DLS). The effectiveness of SiNPs alone and their combination with three common insecticides (emamectin benzoate, indoxacarb, and chlorpyrifos) were evaluated against third instar larvae of fall armyworm. While SiNPs after 24h by leaf dipping method recorded limited insecticidal activity (LC50 = 9947.59mg/L), it significantly enhanced the potency of all three insecticides. Combining SiNPs with emamectin benzoate resulted in the most dramatic increase in effectiveness compared to the insecticide alone with LC50 = 0.295mg/L and 0.42mg/L, respectively. This research suggests that moringa extract can be a valuable resource for the green synthesis of nanoparticles potentially useful in pest control. This approach could potentially reduce the amount of insecticide needed for effective pest control, leading to a more sustainable and environmentally friendly agricultural practice.

Sustainable Pest Management: As an Alternative to Chemical Pesticides

It is critically necessary to make a major transition to a whole system approach for crop protection in order to address the growing environmental and economic effects of managing agricultural pests. The use of chemical pesticides, which can kill non-target species, pollute water supplies, and destroy ecosystems, is lessened through the use of sustainable pest management (SPM). SPM reduces ecological disturbance by utilising biological controls, natural predators, and other eco-friendly techniques. SPM encourages crop diversification, the application of natural enemies, and ecological farming methods that increase biodiversity. As a result, insect outbreaks are decreased and ecosystem resilience is increased.

Thiacloprid-silica nano-delivery system enhances toxicity against Aphis gossypii and improves non-target biosafety

Nanotechnology aligns with the requirements of sustainable development of agriculture, and nano-pesticides offer a promising approach to controlling agricultural pests and increasing productivity. Non-target predators also play a crucial role in pest controls and enhancing the efficacy of pesticide on target organisms. Reducing the toxicity of pesticides to non-target organisms is key to of coordinating chemical control and biological control methods. Therefore, it is essential to assess the toxicity of nano-pesticides on non-target predators. In this study, a carbon dots-doped mesoporous silica nano-delivery system (Thi@CD-MSN) was successfully developed using CD-MSN as carrier material and thiacloprid (Thi) as a model pesticide. The results demonstrated that the synthesized Thi@CD-MSN exhibited a relatively high loading efficiency (33.58%). Laboratory bioassay experiments revealed that Thi@CD-MSN demonstrated effective insecticidal activity (LC50 = 21.67 mg/L) in controlling Aphis gossypii Glover. Besides, the acute toxicity of Thi@CD-MSN on Chrysoperla pallens larvae was significantly lower than that of Thi, as was its toxicity to 4T1 cells. These findings suggest that CD-MSN can serve as an ecological safety carrier for pesticide delivery, improving the effective utilization of Thi while reducing the risks to non-target predators. These results are essential for comprehending the effects of nano-pesticides on non-target predators, providing informative data for implementing biological and chemical control strategies. It strengthens the safety evaluation of nano-pesticides.

Courtship Behavior of Adult Spodoptera frugiperda (Lepidoptera: Noctuidae) Observed Using Track 3D Trajectory Tracking.

Spodoptera frugiperda, also known as the fall armyworm (FAW), is classified by the Food and Agriculture Organization of the United Nations (FAO) as a major agricultural pest. By gaining a more nuanced understanding of the fall armyworm's courtship behavior, simpler and more environmentally friendly methods of controlling this pest can be developed. This study used the Track 3D system to meticulously record and describe the activity characteristics and patterns of adult males and females during courtship. The results show that adult FAWs engaged in a variety of activities during courtship that were either discrete (flying, flapping, moving, and crawling), continuous (flapping + flying, flapping + crawling, and flying + crawling), or combined (flapping + touching + flapping; flying + touching + flying). Flying and flapping were the most common activities, with observed flight patterns consisting of parabolic, circular, and zigzag trajectories. The peak activity times for adult FAWs are mainly concentrated at 11:00 p.m., 3:00 a.m., and 5:00 a.m., providing fundamental data for the precise attraction and control of adult FAWs at later stages.

Accidental Organophosphate Poisoning in a Child: A Case Report Highlighting the Importance of Early Recognition and Treatment

Background: Organophosphate (OP) poisoning is a significant global health concern, especially in developing countries where these chemicals are widely used in agriculture and household pest control. Children are particularly susceptible to accidental OP poisoning due to their inquisitive nature and immature physiology. This case report presents a child with acute muscarinic symptoms following accidental ingestion of an OP insecticide, emphasizing the importance of early recognition and treatment. Case presentation: A 9-year-old boy presented to the emergency department with vomiting, decreased consciousness, and respiratory distress 6 hours after accidentally ingesting an OP insecticide (Baygon) stored in a drinking bottle at home. He exhibited classic muscarinic symptoms, including miosis, hypersalivation, hyperlacrimation, stridor, and wheezing. The patient was treated with atropine and supportive care, resulting in the complete resolution of his symptoms. Conclusion: This case highlights the importance of early recognition and prompt management of OP poisoning in children. Atropine remains the cornerstone of treatment for muscarinic symptoms, and supportive care is crucial to prevent complications. Public health interventions aimed at educating parents and caregivers about the safe storage and handling of OP insecticides are essential to prevent accidental poisoning in children.

Impacts of Various Insecticide Forms on Avian Health and Mortality: A Comprehensive Review

Since the time of its synthesis and application, insecticides have prevented millions of deaths in humans, animals and avian lives. They have significantly contributed to the revolution in agriculture and human health by reducing agricultural pests and vector-borne illnesses. The chance of birds being exposed to insecticides is increased by a number of factors, including farming methods, insect and crop kinds, pesticide form, food, and habitat preferences. Granular insecticides, often used in agriculture, are highly concentrated and attractive to songbirds, shorebirds, and waterfowl. Liquid sprays, particularly those used for locust control, can affect bird species beyond agricultural areas due to wide-range applications. Treated seeds can poison birds depending on various factors like toxicity and seed availability. Despite the known dangers, many pesticide-related bird deaths go unreported, highlighting the need for comprehensive studies to understand and mitigate these effects. Insecticides have a variety of sub lethal effects on birds, such as deformed embryos, smaller broods, less vigilant parenting, weakened territorial defence, anorexia and weight loss, weakened immune response, lethargic behaviour, increased susceptibility to predators, disruption of the endocrine system, interference with thermoregulation, and inability to orient in the correct direction for migration. Therefore, exposure to pesticides lowers the likelihood of survival and successful reproduction, which eventually interferes with the growth of a robust bird population.

Catechol acetylglucose: a newly identified benzoxazinoid-regulated defensive metabolite in maize.

An enormous diversity of specialized metabolites is produced in the plant kingdom, with each individual plant synthesizing thousands of these compounds. Previous research showed that benzoxazinoids, the most abundant class of specialized metabolites in maize, also function as signaling molecules by regulating the production callose as a defense response. We searched for additional benzoxazinoid-regulated specialized metabolites, characterized them, examined whether they too function in herbivore protection, and determined how Spodoptera frugiperda (fall armyworm), a prominent maize pest, copes with these metabolites. We identified catechol acetylglucose (CAG) as a benzoxazinoid-regulated metabolite that is produced from salicylic acid via catechol and catechol glucoside. Genome-wide association studies of CAG abundance identified a gene encoding a predicted acetyltransferase. Knockout of this gene resulted in maize plants that lack CAG and over-accumulate catechol glucoside. Upon tissue disruption, maize plants accumulate catechol, which inhibits S. frugiperda growth. Analysis of caterpillar frass showed that S. frugiperda detoxifies catechol by glycosylation, and the efficiency of catechol glycosylation was correlated with S. frugiperda growth on a catechol-containing diet. Thus, the success of S. frugiperda as an agricultural pest may depend partly on its ability to detoxify catechol, which is produced as a defensive metabolite by maize.

A scaffold protein manages the biosynthesis of steroidal defense metabolites in plants.

Solanaceae plants produce two major classes of valuable sterol derived natural products-steroidal glycoalkaloids and steroidal saponins-from a common cholesterol precursor. Attempts to heterologously produce these molecules have consistently failed, although the genes responsible for each biosynthetic step have been identified. Here we identify a cellulose synthase like protein, an unexpected biosynthetic component that interacts with the early pathway enzymes, enabling steroidal scaffolds production in plants. Moreover, knockout of this gene in black nightshade, Solanum nigrum resulted in plants lacking both steroidal alkaloids and saponins. Unexpectedly, these knockout plants also revealed that steroidal saponins deter serious agricultural insect pests. This discovery provides the missing link to engineer these high value steroidal molecules, and also pinpoints the ecological role for the steroidal saponins.

Whole-Genome Sequencing of the Entomopathogenic Fungus Fusarium solani KMZW-1 and Its Efficacy Against Bactrocera dorsalis.

Fusarium solani KMZW-1 is recognized for its potential as a biocontrol agent against agricultural and forestry pests, particularly due to its compatibility with integrated pest management (IPM) strategies. This study aimed to investigate the complete genome of F. solani KMZW-1 and assess its pathogenicity against Bactrocera dorsalis. Whole-genome sequencing revealed a genome size of 47,239,278 bp, comprising 27 contigs, with a GC content of 51.16% and fungus identified as F. solani KMZW-1. The genome completeness was assessed as 97.93% using BUSCO analysis, the DFVF sequence identifier was Fusarium 0G092560.1, and AntiSMASH analysis identified 35 gene clusters associated with secondary metabolite biosynthesis, providing insights into the genetic basis of its pathogenic mechanisms and biocontrol potential. Comparative genomic analysis found 269 unique genes for F. solani KMZW-1, and collinearity analysis exhibited a high degree of synteny with Fusarium solani-melongenae. The pathogenicity of F. solani KMZW-1 was assessed using concentrations ranging from 1 × 104 to 1 × 1011 conidia/mL. Higher concentrations (1 × 1010 to 1 × 1011 conidia/mL) resulted in significantly increased cumulative mortality rates of B. dorsalis adults compared to the control group. Notably, the pathogenicity was higher in male adults than in females. Probit analysis yielded LC50 (50% lethal concentration) values of 5.662 for female and 4.486 for male B. dorsalis adults. In summary, F. solani, KMZW-1 exhibits strong insecticidal activity against B. dorsalis and shows potential as a biocontrol agent with IPM strategies. These findings provide robust genomic evidence supporting the use of F. solani KMZW-1 in managing against B. dorsalis populations.

Design, Synthesis, and 3D-QASR of Oxazoline Derivatives Containing an S-S Moiety as Potential Acaricide.

To mitigate the detrimental effects of agricultural pest mites on crop yield, an active substructure splicing strategy was employed to modify etoxazole by introducing an S-S moiety. The target products were obtained efficiently via a bilateral disulfurating reagent (DSMO), which was developed by our group. The leaf dip method was used to evaluate the activities of the designed target compounds against the eggs and larvae of the spider mite (Tetranychus cinnabarinus). Most of the target compounds exhibited good efficacy in controlling the larvae and eggs of T. cinnabarinus. Based on these results, a three-dimensional quantitative structure-activity relationship (3D-QSAR) model was established to guide the construction of compound 7l. Notably, compound 7l exhibited a better activity against T. cinnabarinus eggs (LC50 = 0.0035 mg/L) compared to etoxazole (LC50 = 0.2990 mg/L). Greenhouse bioassays indicated that compound 7l exhibits excellent acaricidal activity against egg of T. cinnabarinus, which is better than the etoxazole at 1.0 mg/L. Additionally, some of the compounds showed inhibitory effects against Dickeya zeae (D. zeae), Xanthomonas campestris pv campestris (Xcc), Xanthomonas oryzae pvoryza (Xoo), and Xanthomonas oryzae pvoryzicola (Xoc). Furthermore, compounds 7l not only exhibited relatively potent against Plutella xylostella activities (LC50 = 24.0 mg/L) but also had low toxicity (LC50 > 11.0 μg/bee) to Apis mellifera. In conclusion, the current experimental results suggest that oxazoline derivatives containing an S-S moiety have the potential to serve as lead compounds for the development of novel acaricide agents.