Agricultural Importance Research Articles

Understanding Farmers Perception of Climate Change to Prepare Adaptation of Farmers

The impact of climate change has resulted in a decline in agricultural productivity. This study estimated farmers’ perceptions of climate change by comparing Imogiri Sub-district represent highland area and Pundong Sub-district deputize lowland area farmers in Bantul Regency. This study collected data using questionnaires to 79 respondents then analysis by likerts scale and descriptive statistical. The results showed that there six indicators of climate change became farmers’ perceptions. The farmers perception on highland regarding climate change is that 54% of farmers feel a decrease in rainfall, 54% feel drought, 55.2% feel a longer dry season, 60.8% feel reduced water sources, 74.4% feel a decrease in crop quality and 73.2% feel a decrease in crop quantity. At the same time, the perception of farmers in the lowland area regarding climate change is 66.9% of farmers feel a decrease in rainfall, 68.28% feel drought, 71.03% feel a longer dry season, 68.28% feel reduced water sources, 77.93% feel a decrease in crop quality and 77.93% feel a decrease in crop quantity. The importance of farmers’ perceptions of climate change may be used to adaptation from climate change. Understanding farmers’ perceptions can aid the impact of climate change on agricultural productivity.

Spatial co-transcriptomics reveals discrete stages of the arbuscular mycorrhizal symbiosis

The symbiotic interaction of plants with arbuscular mycorrhizal (AM) fungi is ancient and widespread. Plants provide AM fungi with carbon in exchange for nutrients and water, making this interaction a prime target for crop improvement. However, plant–fungal interactions are restricted to a small subset of root cells, precluding the application of most conventional functional genomic techniques to study the molecular bases of these interactions. Here we used single-nucleus and spatial RNA sequencing to explore both Medicago truncatula and Rhizophagus irregularis transcriptomes in AM symbiosis at cellular and spatial resolution. Integrated, spatially registered single-cell maps revealed infected and uninfected plant root cell types. We observed that cortex cells exhibit distinct transcriptome profiles during different stages of colonization by AM fungi, indicating dynamic interplay between both organisms during establishment of the cellular interface enabling successful symbiosis. Our study provides insight into a symbiotic relationship of major agricultural and environmental importance and demonstrates a paradigm combining single-cell and spatial transcriptomics for the analysis of complex organismal interactions.

Die Abschaffung der steuerlichen Begünstigung von Agrardiesel ist überfällig

Abstract The German Parliament has decided to gradually abolish tax relief for diesel in agriculture. Given the asymmetrical importance of agriculture for the economy and climate, this step was long overdue. Regulatory and distributional policy arguments also speak against maintaining the tax relief.

Effect of Plant Growth-Promoting Bacteria (PGPB) on the Development of Pea crop (Pisum sativum L.)

Microorganisms are of great importance in agriculture in terms of plant nutrients by reducing the need for chemical fertilization. In recent years, plant growth-promoting bacteria (PGPB) have been widely used as biological fertilizers (BF) in agriculture. This study was conducted to determine the effect of plant growth-promoting bacteria on the development of pea plants. Firstly the phosphate solubilization and nitrogen fixation potentials of the bacteria used in this study were determined. In the study, the effects of 4 different combinations, F1 [(Rhizobium sp. (FR-13) and Pseudomonas alcaligenes (FDG121)], F2 [(Pseudomonas fluorescens biotype F (FDG-7), Rhizobium sp. (FR-18) and Bacillus-megaterium-GC subgroup B(FDG-134)], F3 [Arthrobacter oxydans (FDG-72), Bacillus-megaterium-GC subgroup B (FDG-146), Rhizobium sp. (FR-11)] and F4 [Acinetobacter genospecies 9 (FDG-116), Brevibacillus agri (FDG-118), Methylobacterium zatmanii (FDG-123) and Bacillus-megaterium-GC subgroup A (FDG-153)] were investigated. Formulations made with bacteria that were found to be the best in terms of the properties specified among these strains were tested against pea plants under greenhouse conditions and their effects on the plant's total fresh and dry weight were investigated. The study was set up to have 3 replications. As a result of the statistical analysis made with the data obtained, the formulations used compared to the control; F2, F3 and F1 applications were important in total fresh weight, respectively, and F2 and F3 applications were important in total dry weight. As a result, these 3 formulations are especially effective on the yield of pea plants and can be used as potential biofertilizers.

Comparative analysis and prediction of cation exchange capacity via summation: influence of biochar type and nutrient ratios

IntroductionEnhancing soil cation exchange capacity (CEC) is of paramount importance for sustainable agriculture and ecosystem health. This study investigated the pivotal role of biochar in altering soil CEC and challenges conventional assumptions about universal effects of biochar application.MethodsContrasting biochar types, one with a low ash content of 4.4% (switchgrass-derived biochar, SGB) and the other with a high ash content of 45.9% (poultry litter-derived biochar, PLB) were used. Two experiments treated with increasing biochar application rates were conducted: one without plants and the other grown with ryegrass. Effective CEC (summation method) was determined by two extraction methods: Mehlich-3 (M3) and ammonium acetate (AA).Results and discussionThe SGB decreased CEC by 27% on average (from both experiments) from the lowest to the highest rate of biochar application, while the PLB significantly increased CEC by 91%. This highlights the critical role of biochar properties in influencing CEC dynamics. In the second experiment, ryegrass cultivation revealed the greater importance of the calcium and magnesium/potassium ratio ([Ca+Mg]/K) in the soil CEC than CEC only for plant growth in biochar-amended soils. The ratios for optimum ryegrass production ranged from 82‒86 (M3) and 69‒74 (AA), which was translated to 88:11:1 Ca:Mg:K percent base saturation ratios. Moreover, predictive models for estimation of soil CEC after biochar application were successfully developed based on initial soil and biochar CEC. However, M3 was more reliable than AA for such predictions mainly because it was more successful in predicting nutrient availability from biochar. These models offer a promising tool for informed soil management decisions.ConclusionThis research emphasizes the importance of biochar feedstock, elucidates nutrient ratio effects on plant growth, and provides a practical means to anticipate soil CEC changes post-biochar application.

Heterogeneous trade effects of technical non‐tariff measures: Vietnamese agricultural imports

This study investigates the impact of technical non‐tariff measures (NTMs), specifically technical barriers to trade (TBT) and sanitary and phytosanitary (SPS), of Vietnam on agricultural imports and the role of deep trade agreements. This issue has been primarily focused on advanced countries but rarely studied for developing countries. The estimates indicate that the impacts of technical NTMs on imports from least developed countries (LDCs) and non‐LDCs are heterogeneous in terms of the measures' sophistication level. Simple technical NTMs, namely labelling, marking, and packaging requirements, increase agricultural imports from LDCs, while there is no significant impact on those from non‐LDCs. Other categories of TBT and SPS NTMs impede imports from LDCs, while benefiting imports from non‐LDCs. In addition, we found that deep trade agreements can ease the burdens of technical NTMs, but this is limited to imports from non‐LDCs. The findings of this study can help policymakers in better regulating agricultural imports to prevent harmful imports with minimal impacts on the benefits from trade.

Economic Efficiency of Banana Production in Uttara Kannada District of Karnataka, India

Aim: Banana cultivation holds significant agricultural importance, contributing substantially to global dietary staples. This study Examines the economic efficiency of banana production in Uttara Kannada district.
 Sampling Design: Employed purposive and multistage sampling, the study focuses on Sirsi and Siddapur taluks, selecting 80 farmers through random sampling.
 Methodology: The research examines resource utilization by employing the Cobb-Douglas production function and evaluate efficiency levels by Data Envelopment Analysis (DEA).
 Results: Allocative efficiency in banana cultivation is apparent through positive MVP/MFC ratios for inputs like suckers (15.89), manure (1.91), fertilizers (7.21), machine labor (1.75), and propping material (6.66), indicating underutilization. Conversely, plant protection chemicals (-22.35) and human labor (-1.20) show negative ratios, signifying overutilization. The ratio of MVP to MFC was differed from unity indicating scope for reallocation of expenditure among various resources. Using Data Envelopment Analysis, individual farm technical and economic efficiency was assessed. Banana, Crop I had a mean technical efficiency of 70.30, while Crop II had 49.40. The results highlight room for improvement, especially in Crop II, emphasizing the need for better resource allocation. Major production constraints include labour scarcity, poor planting material, and pest issues. Marketing hurdles encompass price fluctuations, limited storage, and distant markets.
 Conclusion: The study emphasizes the banana cultivation revealed significant impacts of resource utilization on yield, with suckers, fertilizers, and plant protection chemicals showing substantial effects. Allocative efficiency analysis indicated underutilization of resources, suggesting potential for yield improvement. However, farmers face challenges including labour scarcity, quality planting material, price fluctuations, and inadequate storage facilities in production and marketing.

Dof1.7 and NIGT1 transcription factors mediate multilayered transcriptional regulation for different expression patterns of NITRATE TRANSPORTER2 genes under nitrogen deficiency stress.

Elucidating the mechanisms regulating nitrogen (N) deficiency responses in plants is of great agricultural importance. Previous studies revealed that decreased expression of NITRATE-INDUCIBLE GARP-TYPE TRANSCRIPTIONAL REPRESSOR1 (NIGT1) transcriptional repressor genes upon N deficiency is involved in N deficiency-inducible gene expression in Arabidopsis thaliana. However, our knowledge of the mechanisms controlling N deficiency-induced changes in gene expression is still limited. Through the identification of Dof1.7 as a direct target of NIGT1 repressors and a novel N deficiency response-related transcriptional activator gene, we here show that NIGT1 and Dof1.7 transcription factors (TFs) differentially regulate N deficiency-inducible expression of three high-affinity nitrate transporter genes, NRT2.1, NRT2.4, and NRT2.5, which are responsible for most of the soil nitrate uptake activity of Arabidopsis plants under N-deficient conditions. Unlike NIGT1 repressors, which directly suppress NRT2.1, NRT2.4, and NRT2.5 under N-sufficient conditions, Dof1.7 directly activated only NRT2.5 but indirectly and moderately activated NRT2.1 and NRT2.4 under N-deficient conditions, probably by indirectly decreasing NIGT1 expression. Thus, Dof1.7 converted passive transcriptional activation into active and potent transcriptional activation, further differentially enhancing the expression of NRT2 genes. These findings clarify the mechanism underlying different expression patterns of NRT2 genes upon N deficiency, suggesting that time-dependent multilayered transcriptional regulation generates complicated expression patterns of N deficiency-inducible genes.

Reviewing impacts of biotic and abiotic stresses on the regulation of phosphate homeostasis in plants.

Adapting to varying phosphate levels in the environment is vital for plant growth. The PHR1phosphate starvation response transcription factor family, along with SPX inhibitors, plays a pivotal role in plant phosphate responses. However, this regulatory hub intricately links with diverse biotic and abiotic signaling pathways, as outlined in this review. Understanding these intricate networks is crucial, not only on a fundamental level but also for practical applications, such as enhancing sustainable agriculture and optimizing fertilizer efficiency. This comprehensive review explores the multifaceted connections between phosphate homeostasis and environmental stressors, including various biotic factors, such as symbiotic mycorrhizal associations and beneficial root-colonizing fungi. The complex coordination between phosphate starvation responses and the immune system are explored, and the relationship between phosphate and nitrate regulation in agriculture are discussed. Overall, this review highlights the complex interactions governing phosphate homeostasis in plants, emphasizing its importance for sustainable agriculture and nutrient management to contribute to environmental conservation.

Ретроспективный анализ эволюции системы продовольственного обеспечения

A retrospective study of the evolutionary transformation of the concept of food security in the context of Russian reality has been conducted. Currently, food security, as an integral part of national security, has become the cornerstone for maintaining economic stability and political autonomy in the country. With increasing geopolitical volatility and private food crises, this topic is becoming increasingly relevant, and maintaining national food security has taken a leading position among the priorities for each State. At the same time, the analysis of scientific research on this topical issue proves that the formation of national food security depends on its regional food security, therefore it is also especially important to study and improve regional food supply systems. It is determined that food security is an active integration process of interaction between internal and external factors, such as agricultural production, grain stocks, import and export of grain, international food aid, etc. It is noted that the modern food supply system must be considered as a complex system of macroeconomic organization that ensures a balance between food and the demand of the population. The analysis of the elements and characteristics of this system makes it possible to identify the most important problems of its functioning and development, the solution of which contributes to improving the efficiency of work and, as a result, to guarantee the necessary and sufficient level of national food security in conditions of high variability of the surrounding environment. At the same time, the national food security system is closely interrelated with the level of regional food management systems, and the modern concept of food security implies the need to ensure constant access to physical and economic nutrition for every citizen.

Current Status of Herbicide Resistance of Wild Oats (Avena spp) in Wheat Fields in Mardin and Şanlıufa Provinces of Türkiye

Wheat is a strategic crop with its role in human nutrition. In Türkiye, it has importance in agriculture and economy as well as being a staple crop. Mardin and Şanlıurfa provinces of Türkiye approximately produces 1.6 million tons of wheat on 600 thousand ha fields. One of the important factors limiting wheat production is weeds. Weeds compete with the wheat plant and cause significant yield and quality loss. Wild oat (Avena spp.) species are an important problem in wheat fields in both provinces. Herbicide applications are widely used to control wild oats due to their ease of use, short duration of action and low cost. Wheat fields were surveyed to supply data for strategies to be followed via determining the current situation of herbicide resistance in these provinces where herbicide resistant wild oats had been reported. Out of 95 fields visited, 65 fields had significant wild oat populations of which 61 A. sterilis and four A. fatua. Then these populations were tested to find out herbicide resistance levels against clodinafop-propargyl (ACCase inhibitor) and formulated mix of mesosulfuron-methyl and iodosulfuron-methyl sodium (ALS inhibitors). Only two populations, one low level and the other medium level were found to be resistant to the formulated mix of mesosulfuron and iodosulfuron while 11 populations were resistant to clodinafop, one high level, three medium level and the remaining low level. It was assumed that longer use history and wider use of clodinafop as well as herbicides used in winter rotational crops might cause more clodinafop resistant populations. It was concluded that a strategy to prevent or delay herbicide resistance in these provinces should be prepared because herbicide resistance has continued evolving.

The Application of Wheat Farmers to Modern Agriculture Technology Related to Improve Crop Production in Thi-Qar

The research aim is to determine the level of application farmers of Modern Agricultural Technology have in improving wheat crop production in Thi-Qar Province. A multistage sample probability proportionates of size (PPS) was used to conduct this study. The sample number was (75 farmers from the Qalat Sukkar district, 105 farmers from the AL-Rifai district, 45 farmers from the AL-Shatrah district, and 29 farmers from the AL-Nasr district) (15% of the total number of farmers) it was 254 farmers. Questionnaire techniques and interviews with the farmers were adopted to collect the data (March to May 2019). The study has revealed that the highest percentage (62.6 %) belonged to the medium category in applying modern agricultural technology to improve wheat crop production. The application level of modern agricultural technology was significant and positive at a 1% probability level under six variables. Multiple regression analyses have been studied with ten variables: social class, age, Education, Occupation, Farm power, Size of land holding, Family type, Family size, social participation, and source of information utilized. This research has contributed nine independent variables with significant levels of variation to the extent of the application level of modern agricultural technology in improving wheat crop production (R2= 0.759). The importance of farmers using modern agricultural technology with the parts (Soil preparation, Planting and crop service, harvesting processes and marketing) was high according to (72.12, 70.72, and 68.41) respectively. The data were used for analysis: Frequency, percentage, mean, Standard deviation, and multiple regression analysis. According to the result, farmers' application of modern technology in improving wheat crop production was good. Modern agricultural technology will reduce costs, increase productivity, and save soil quality. The importance of farmers with the parts (Soil preparation, Planting, crop service, harvesting processes, and marketing) was high according to (72.12, 70.72, and 68.41) respectively. Because of this, it is necessary to improve the cultivation of wheat crops to achieve high productivity and reduce the problems that happen during agricultural production. Keywords: Technology, Independent variables, Farmers, Harvesting, Size of land holding

The Application of Wheat Farmers to Modern Agriculture Technology Related to Improve Crop Production in Thi-Qar

The research aim is to determine the level of application farmers of Modern Agricultural Technology have in improving wheat crop production in Thi-Qar Province. A multistage sample probability proportionates of size (P.P.S.) was used to conduct this study. The sample number was (75 farmers from the Qalat Sukkar district, 105 farmers from the AL-Rifai district, 45 farmers from the AL-Shatrah district, and 29 farmers from the ALNasr district) (15% of the total number of farmers) it was 254 farmers. Questionnaire techniques and interviews with the farmers were adopted to collect the data (March to May 2019). The study has revealed that the highest percentage (62.6 %) belonged to the medium category in applying modern agricultural technology to improve wheat crop production. The application level of modern agricultural technology was significant and positive at a 1% probability level under six variables. Multiple regression analyses have been studied with ten variables: social class, age, Education, Occupation, Farm power, Size of land holding, Family type, Family size, social participation, and Source of information utilized. This research has contributed nine independent variables with significant levels of variation to the extent of the application level of modern agricultural technology in improving wheat crop production (R2= 0.759). The importance of farmers using modern agricultural technology with the parts (Soil preparation, Planting and crop service, harvesting processes and marketing) was high according to (72.12, 70.72, and 68.41) respectively. The data were used for analysis: Frequency, percentage, mean, Standard deviation, and multiple regression analysis. According to the result, farmers' application of modern technology in improving wheat crop production was good. Modern agricultural technology will reduce costs, increase productivity, and save soil quality. The importance of farmers with the parts (Soil preparation, planting, crop service, harvesting processes, and marketing) was high according to (72.12, 70.72, and 68.41) respectively. Because of this, it is necessary to improve the cultivation of wheat crops to achieve high productivity and reduce the problems that happen during agricultural production. Keywords: Technology, Independent variables, Farmers, Harvesting, Size of land holding

A multiplex direct PCR method for the rapid and accurate discrimination of three species of spider mites (Acari: Tetranychidae) in fruit orchards in Beijing.

Spider mites (Acari: Tetranychidae) are polyphagous pests of economic importance in agriculture, among which the two-spotted spider mite Tetranychus urticae Koch has spread widely worldwide as an invasive species, posing a serious threat to fruit tree production in China, including Beijing. The hawthorn spider mite, Amphitetranychus viennensis Zacher, is also a worldwide pest of fruit trees and woody ornamental plants. The cassava mite, Tetranychus truncatus Ehara, is mainly found in Asian countries, including China, Korea and Japan, and mainly affects fruit trees and agricultural crops. These three species of spider mites are widespread and serious fruit tree pests in Beijing. Rapid and accurate identification of spider mites is essential for effective pest and plant quarantine in Beijing orchard fields. The identification of spider mite species is difficult due to their limited morphological characteristics. Although the identification of insect and mite species based on PCR and real-time polymerase chain reaction TaqMan is becoming increasingly common, DNA extraction is difficult, expensive and time-consuming due to the minute size of spider mites. Therefore, the objective of this study was to establish a direct multiplex PCR method for the simultaneous identification of three common species of spider mites in orchards, A. viennensis, T. truncatus and T. urticae, to provide technical support for the differentiation of spider mite species and phytosanitary measures in orchards in Beijing. Based on the mitochondrial cytochrome c oxidase subunit I (COI) of the two-spotted spider mite and the cassava mite and the 18S gene sequence of the hawthorn spider mite as the amplification target, three pairs of specific primers were designed, and the primer concentrations were optimized to establish a direct multiplex PCR system for the rapid and accurate discrimination of the three spider mites without the need for DNA extraction and purification. The method showed a high sensitivity of 0.047ng for T. truncatus and T. urticae DNA and 0.0002ng for A. viennensis. This method eliminates the DNA extraction and sequencing procedures of spider mite samples, offers a possibility for rapid monitoring of multiple spider mites in an integrated microarray laboratory system, reducing the time and cost of leaf mite identification and quarantine monitoring in the field.

Induced Resistance Mechanism in Plant and Its Importance in Agriculture

The search for a successful and efficient natural phenomenon of induced resistance in plants was prompted by the harmful effects that chemical pesticides and their degradation products had on the environment and human health. Ray was the first to identify plant resistance to diseases in 1901. When arabidopsis plants were injected with the pathogenic bacteria Pseudomonas fluorescens, which colonises roots, induced resistance was initially observed in these plants. There are two different kinds of induced resistance: induced biochemical defense and induced structural defense. Biochemical defense includes phytoalexins, PR-proteins, and secondary metabolites; structural defense includes cytoplasmic reactions, cell wall defense structure, and histological defense structure (development of cork layers, abscission layer, and tylose). Induced systemic resistance (ISR) and systemic acquired resistance (SAR) are the foundation of the induced resistance process. While the defense mechanism in ISR is mediated by jasmonic acid and ethylene and additionally triggered by non-pathognic rhizobacteria (Pseudomonas fluorescens), the defense mechanism in SAR is salicyclic mediated, namely alterations in gene expression. Plants can develop resistance to specific diseases by applying exogenous doses of 2, 6-dichloroisonicotonic acid and benzo-thiadiazole-7-carbothioic acid S-methyl ester (BTH). Induced resistance in plants, while still poorly understood, offers up new possibilities for plant protection and presents a viable strategy for sustainable agriculture and environmentally friendly disease control. It continues to be a problem for both basic and practical research.

Structural and Dynamic Changes in International Trade in Agricultural Products in Ukraine

The article is devoted to studying the structural and dynamic changes in international trade in agricultural products in Ukraine. The authors reveal the theoretical essence of international trade in agricultural products, considering export and import conditions in light of modern challenges. The assessment of the foreign trade regime is provided and the trends and impact of implementing the Agreement on Association between Ukraine and the EU on the development of Ukraine's foreign trade are established. It was found that, on one hand, the export orientation of raw materials to the EU crop production market has increased, while on the other hand, there remains a high import dependence on prepared food products, with a more diversified import structure. The peculiarities of key directions of Ukraine's agro-industrial market under martial law and its place in the global food security system are described. The article also examines the structure of Ukraine's trading partners, which have been revised since the beginning of the war. The peculiarities of cooperation between Ukraine and the EU in international trade in agricultural products are analysed. Ways of diversifying exports and increasing the profitability of foreign trade in agricultural products from Ukraine in the EU market are suggested.

Leaf diseases detection empowered with transfer learning model

<p>The detection of leaf diseases using modern technology has significant importance in agriculture and artificial intelligence. Deep learning, specifically, plays a crucial role in this field, as it enables accurate and efficient disease classification. Early detection of leaf diseases is vital to implementing timely treatments and preventing widespread damage to leaves. Leaf diseases can be caused by various factors, including bacteria, fungi, viruses, and other pathogens. Among them, bacteria and viruses are the most invasive and can lead to substantial yield losses if not identified and treated promptly. Bacterial and viral infections are common in agricultural settings, affecting leaves of all types and ages. Our research aims to propose a transfer learning-based model for predicting leaf diseases using a dataset of leaf images. The images will be classified into healthy or diseased leaves based on extracted features. The proposed model, named Leaf Disease Transfer Learning Algorithm (LDTLA), demonstrates promising results with an average accuracy of 97.37% on the dataset. Utilizing convolutional neural networks (CNN) and deep learning techniques, our LDTLA model outperforms previous quantitative and qualitative research studies in leaf disease detection. This advanced approach to leaf disease identification holds the potential to revolutionize agriculture by enabling farmers to make informed decisions, implement targeted treatments, and minimize leaf losses caused by diseases.<strong></strong></p>

The Impact of Participating in the Regional Comprehensive Economic Partnership (RCEP) Agreement and Potential Export Markets for Vietnamese Rice: An Application of Augmented Gravity Model

In this study, we investigate the potential effects of the Regional Comprehensive Economic Partnership (RCEP) agreement on Vietnam’s rice exports from 2000 to 2016. For this analysis, we employ the panel data augmented gravity model with some modifications. The estimated results suggest a positive relationship between Vietnam’s per capita export and the capita real gross domestic product (GDP) of the importer, Vietnam’s rice production, export price, and ASEAN dummy. We confirm that there is a negative relationship between Vietnam’s per capita rice export value and import country agricultural land and import tariffs. Additionally, this paper forecasts Vietnam’s rice export value per capita at each market in RCEP partners by using the autoregressive model. Our forecast results show that among RCEP members, Vietnam has potential markets if import tariff reductions are lowered in Singapore, Brunei, Korea, Japan, and Malaysia. To reap the benefits of rice exports’ potential, Vietnam must move from low-grade and cheap rice to high-quality rice production instead of expanding rice production and exports with the following implications: changing its present rice trading partners to potential markets and adopting market-oriented policies to meet the international demand and to increase the export elasticity of rice.

Low prevalence of secondary endosymbionts in aphids sampled from rapeseed crops in Germany.

Peach-potato aphids, Myzus persicae Sulzer (Hemiptera:Aphididae), and cabbage aphids, Brevicoryne brassicae Linnaeus (Hemiptera:Aphididae), are herbivorous insects of significant agricultural importance. Aphids can harbour a range of non-essential (facultative) endosymbiotic bacteria that confer multiple costs and benefits to the host aphid. A key endosymbiont-derived phenotype is protection against parasitoid wasps, and this protective phenotype has been associated with several defensive enodsymbionts. In recent years greater emphasis has been placed on developing alternative pest management strategies, including the increased use of natural enemies such as parasitoids wasps. For the success of aphid control strategies to be estimated the presence of defensive endosymbionts that can potentially disrupt the success of biocontrol agents needs to be determined in natural aphid populations. Here, we sampled aphids and mummies (parasitised aphids) from an important rapeseed production region in Germany and used multiplex PCR assays to characterise the endosymbiont communities. We found that aphids rarely harboured facultative endosymbionts, with 3.6% of M. persicae and 0% of B. brassicae populations forming facultative endosymbiont associations. This is comparable with endosymbiont prevalence described for M. persicae populations surveyed in Australia, Europe, Chile, and USA where endosymbiont infection frequencies range form 0-2%, but is in contrast with observations from China where M. persicae populations have more abundant and diverse endosymbiotic communities (endosymbionts present in over 50% of aphid populations).

Mating harassment may boost the effectiveness of the sterile insect technique for Aedes mosquitoes

The sterile insect technique is based on the overflooding of a target population with released sterile males inducing sterility in the wild female population. It has proven to be effective against several insect pest species of agricultural and veterinary importance and is under development for Aedes mosquitoes. Here, we show that the release of sterile males at high sterile male to wild female ratios may also impact the target female population through mating harassment. Under laboratory conditions, male to female ratios above 50 to 1 reduce the longevity of female Aedes mosquitoes by reducing their feeding success. Under controlled conditions, blood uptake of females from an artificial host or from a mouse and biting rates on humans are also reduced. Finally, in a field trial conducted in a 1.17 ha area in China, the female biting rate is reduced by 80%, concurrent to a reduction of female mosquito density of 40% due to the swarming of males around humans attempting to mate with the female mosquitoes. This suggests that the sterile insect technique does not only suppress mosquito vector populations through the induction of sterility, but may also reduce disease transmission due to increased female mortality and lower host contact.