Use Of Biopesticides Research Articles

A pipeline for the genetic improvement of a biological control agent enhances its potential for controlling soil-borne plant pathogens

Use of biopesticides results in a reduction of the worldwide dependence on chemical pesticides, ending in a more sustainable crop protection. For this reason, biological control industry invests in continued research for more effective biocontrol agents (BCAs) using basically two strategies: isolation of new strains from nature or conventional genetic improvement. However, both are highly onerous and time-consuming. Here we show a pipeline for the genetic improvement of fungal BCAs, based on genome shuffling, the most recent and promising non-recombinant DNA technology for the rapid phenotype improvement of microbial strains. The method consisted of the construction of a parent library using mutagenic agents, followed by genome shuffling and high-throughput screening. Sarocladium oryzae BRM 6461, a known cerulenin antifungal producer strain and high biocontrol potential, served as the model fungal BCA. The pipeline aimed to select mutant enhanced strains at least one of these three desirable characteristics: antagonism, UV-B irradiation tolerance and high temperature tolerance. The experiments were conducted in laboratory and green house. After four cycles of genome shuffling we selected the superior S. oryzae GS4-03 strain, showing cerulenin production of 203.3 ± 1.4 µg/mL, 42% higher than the wild-type strain BRM 6461. The GS4-03 strain exhibited good genetic stability for at least five successive subcultivation assays. Antagonism assay showed an increased micelial inhibition of Rhizoctonia solani and Sclerotinia sclerotiorum when using GS4-03 strain compared to the BRM 6461 strain. The bioassays, showed that the superior strain GS4-03 have an increased ability to control root rot (23.4%) and white mold (8.1 times) disease compared to the wild type strain BRM 6461. Assessment of virulence of the superior strain GS4-03 against rice plants showed that improvement procedures did not change the original strain behavior in this subject. Hydrolytic activity of enzymes related to the biocontrol action as chitinase, protease and β-1,3-glucanase did not present statistical difference between GS4-03 and BRM 6461 strains. Results of dual assay culture between GS4-03 and BRM 6461 strains showed that both have different genetic backgrounds, although RAPD and ITS-rDNA tests were not fully efficient to distinguish genetically the strains. Moreover, mutations resulted in S. oryzae strains more tolerant to UV-B irradiation, but with low genetic stability. Our results report for the first time an efficient pipeline for the genetic improvement of fungal BCAs based on genome shuffling.

Bacillus thuringiensis Bioinsecticides Induce Developmental Defects in Non-Target Drosophila melanogaster Larvae.

Simple SummaryThe use of chemical pesticides is controversial mainly because of their detrimental effects on both the environment and human health. Public opinion along with government policies encourage reductions in their exploitation. An emerging solution is the use of biopesticides, which sales are currently increasing. Among biopesticides, the bacterium called Bacillus thuringiensis is the most used bioinsecticide both in organic and conventional farming to fight larval pests. One strain of Bacillus thuringiensis produces toxins that specifically kill lepidopteran (butterfly) larvae in two or three days. However, although not lethal for other insects such as bees or fruit flies, Bacillus thuringiensis may affect their development. Only scarce data are currently available on the unintended effects of Bacillus thuringiensis strains on insects other than those targeted. In this study, we characterized the adverse effects of Bacillus thuringiensis strains that target lepidopteran larvae, on the development of the fruit fly Drosophila melanogaster, a dipteran non-target insect. We showed that amounts of Bacillus thuringiensis in the nutritive medium close to the amounts found on vegetables after treatment induced developmental and growth defects in Drosophila larvae. We further showed that these effects are due to the disturbance of the larval intestinal physiology, reducing protein digestion.Bioinsecticides made from the bacterium Bacillus thuringiensis (Bt) are the bestselling bioinsecticide worldwide. Among Bt bioinsecticides, those based on the strain Bt subsp. kurstaki (Btk) are widely used in farming to specifically control pest lepidopteran larvae. Although there is much evidence of the lack of acute lethality of Btk products for non-target animals, only scarce data are available on their potential non-lethal developmental adverse effects. Using a concentration that could be reached in the field upon sprayings, we show that Btk products impair growth and developmental time of the non-target dipteran Drosophila melanogaster. We demonstrate that these effects are mediated by the synergy between Btk bacteria and Btk insecticidal toxins. We further show that Btk bioinsecticides trigger intestinal cell death and alter protein digestion without modifying the food intake and feeding behavior of the larvae. Interestingly, these harmful effects can be mitigated by a protein-rich diet or by adding the probiotic bacterium Lactobacillus plantarum into the food. Finally, we unravel two new cellular mechanisms allowing the larval midgut to maintain its integrity upon Btk aggression: First the flattening of surviving enterocytes and second, the generation of new immature cells arising from the adult midgut precursor cells. Together, these mechanisms participate to quickly fill in the holes left by the dying enterocytes.

Quantitative analysis of fresh tomatoes (Solanum lycopersicum) for trace of pesticide residues from markets in Peshawar, Pakistan, using High Performance Thin Liquid Chromatography technique

Background: Vegetables and fruits are vital constituents of human diet, as it provides necessary minerals and nutrients to human body to carry out biological reactions and provide protection against various diseases and injuries. Solanum lycopersicum (tomato) is consider as cash crop in Asian countries and are fine source of vitamin C, potassium, folate, vitamin K, and other bioactive compounds including, phenolics, flavonoids, carotenoids, and alkaloids. Similar to other crops, tomato quality and yield is also affected by pests. Globally, approximately 37.8% of tomato yield is spoiled due to pests. To maintain the vegetable quality and attain more yield, pest management approaches are applied, though extensive use of toxic pesticides are becoming a part of our food chain and causing adverse effects.
 Methodology: The present research is intended to evaluate the levels of toxic pesticides in different tomato varieties collected from four vegetable markets (Hayatabad Phase 1, Chargano Chowk, Kohat Road and Tarnab farm) in Peshawar, Pakistan. After collection of tomato samples, level of pesticide residues (Cyhalothrin, Cypermethrin, Chlorpyrifos, Bifenthrin, and Imidacloprid) were detected using high performance thin liquid Chromatography (HPTLC).
 Results: After detection, level of pesticides in sample was compared with Maximum residue levels (MRLs). The magnitude of pesticides in samples was lesser to the Maximum residue levels (MRLs) provided by United State Drug Agency (USDA), though the quantity of Lambda Cyhalothrin present in the sample was almost equal to MRL (0.097 mg/kg).
 Conclusion: HPTLC is an efficient approach to detect pesticide traces in fruits and vegetables. Research work should be focused on it, to identify and control farmer practices which are highly linked to pesticide contamination in tomatoes and use of biopesticides should be encouraged. The cultivation of transgenic tomatoes can also be an efficient approach to elude the utilization of toxic pesticides.

Field efficacy of insecticide, biopesticide and pheromone trap against pea pod borer in District Shimla

Pea is the second most important crop in apple growing regions of Himachal Pradesh after apple and growing legumes enriches the soil health because of their nitrogen fixing ability in soil. Pea pod borer is the serious pest of pea crop. The caterpillar not only defoliates the tender leaves but also makes holes in the pods and feed upon the developing grains. Therefore, the present studies on efficacy of some pesticides (insecticides+biopesticides) viz., Deltamethrin (Decis), Azadirachtin (Neem Gold), Bacillus thuringiensis var. kurstaki (Mahastra) and pheromone trap with Helilure capsule were carried out against the pea pod borer infesting pea and further their effect on the yield of the pea crop was also studied at farmer’s field in Village Badiyara, PO Jangla, Tehsil Chirgaon Distt. Shimla, Himachal Pradesh during two consecutive years. The experiment comprised of five treatments viz., T1- Pheromone trap with Helilure capsule + Bacillus thuringiensis var. kurstaki @2g/lt, T2- Bacillus thuringiensis var. kurstaki @2g/lt, T3- Azadirachtin @3ml/lt, T4- Deltamethrin @1ml/lt and T5- Control (water only) with three replications. The pheromone trap with Helilure capsule was installed in the pea field when the crop was 30-days old and the spray was given after the emergence of the pest and the data on pod borer population were recorded after 1, 3 and 5 days after the pesticide applications. The results of the study revealed that there was reduction in the larval population of the pod borer and the highest mortality was recorded in the treatment T1 (1.36 larvae/ plant) with pheromone trap having Helilure capsule + Bacillus thuringiensis var. kurstaki @2g/lt followed by T2 treatment (2.26 larvae/ plant) which was statistically at par with T3 (2.30 larvae/ plant) and T4 (2.40 larvae/ plant) while it was the lowest in T5 treatment (5.83 larvae/ plant). Among the treated plots, significantly highest yield of pea crop was recorded in the T1 treatment having 61q/ ha yield while the minimum yield of 49.5q/ ha was recorded in T5 (Control) treatment. Hence, the use of biopesticides with Pheromone trap should be encouraged in future as it is not only eco-friendly but economical as well.

Bioefficacy of Some Botanicals Against Gum Arabic Borer, Bruchus baudni Caill (Coleoptera: Bruchidae) on Stored Senegalia senegal Seeds

The use of bio-pesticides has proven to be successful approach in controlling agricultural insect pests. Study was conducted in the Laboratory of the Department of Crop Protection, Faculty of Agriculture, Bayero University, Kano to study the Biology of Bruchus baudni on treated Senegalia senegal seeds. Seed oils and leaf powders of K. senegalensis and M. oleifera at three concentrations each, a chemical insecticide (Aluminum phosphide as standard check) and a control were laid out in a Completely Randomized Design (CRD) and replicated three times. Data collected were oviposition, egg hatchability and developmental stages. The results indicated significant reduction in the number of eggs laid (1% and 1.38%) and hatchability (0.00% and 0.57%) on both seed oil and leaf powder treatments, respectively; however, the control recorded the highest eggs laid (99.9%) and number of emerged B. baudni (99.2%). The present findings showed that seeds and leaves of mahogany and moringa were effective as protectant against some of the development stages of B. baudni. Therefore, based on the present results, mahogany and moringa seeds and leaves could be explored to replace the synthetic insecticides in the management of B. baudni especially as components of integrated pest management strategy.

PENINGKATAN KAPASITAS PETANI DALAM PENERAPAN BIOPESTISIDA PENGENDALI HAMA PADA TANAMAN PADI SAWAH (Oryza sativa L.) DI DESA CIASMARA KECAMATAN PAMIJAHAN

Pest attacks in the agricultural sector have become commonplace in every planting season and even pest attacks can reduce rice productivity 2-4 tons / ha, new farmers apply pest control according to the recommendations of around 38-40% less than 50% of the extension agent's target so the importance of using biopesticides as an effort to reduce pest attacks through the application of Pest Control Biopesticides which aim to Describe the increase in farmer capacity in the application of Pest Control Biopesticides, Analyze Factors related to increasing the capacity of farmers in the application of Pest Control Biopesticides in rice plants. The study was conducted in Ciasmara Village, Pamijahan District. The sample of the research is active farmers who are 40 members of farmer groups, using Descriptive Data Analysis, Spearman Rank Analysis. The results of research on improving the capacity of farmers in the application of biopesticides at the Knowledge stage are starting to recognize the existence of innovations and gain some understanding of the innovations functioning, followed by the stages of persuasion (Action), and decisions until confirmation. There is a positive (unidirectional) relationship between formal education, cosmopolitan, environmentally friendly paddy technology innovation, extension of environmentally friendly innovation, and agricultural technology information with increasing capacity of paddy farmers in Ciasmara village with a strong level of correlation (correlation), and there is influence in the use of biopesticides against pest reduction in lowland rice plants

Eco-friendly management of plant parasitic nematodes

Background/Objective: Root-knot nematodes and cyst nematodes are two important plant-parasitic nematodes that cause severe plant diseases in various plant species around the world. They act as obligate and biotrophic parasite within the plant body. The objective of the study is to review for suitable management to keep the nematode population density below the threshold level. Methods: In spite of several nematode control practices such as crop rotation, use of biopesticides or nematicides, each has some limitations of their use but biotechnological applications including RNAi or miRNA represent a potential breakthrough in the application of functional genomics for plant nematode control. Here, a comparison is made between some old and modern nematode management practices but recent data shows that application of RNAi or miRNA has a better option of nematode control in some crop plants. Findings: Efficacy and biotechnological success can be maintained by holistic grasping of several soil biological and ecological factors. Therefore, modern approaches those reviewed herein due to their usefulness in minimizing plant nematode populations and increasing crop yield should be incorporated into management systems. The scientific community has entered into a new era that shows the tools to actually unravel the underlying molecular mechanisms, making this an opportunity for a review of our current knowledge and better understanding. Application: These modern eco-friendly practices may not quickly perform as synthetic chemicals, but they are pest specific, non-toxic to humans or environment, and also serves as a sustainable tool for disease management. Novelty: The present communication identifies plant nematode control approaches with emphasis on modern research. This review article emphasized the importance of modern biotechnological approaches for better crop yield than the common older practices. Keywords: Root-Knot nematode; biotrophic Parasite; threshold level; nematicides; biopesticide; micro RNA

Pest status, bio-ecology and management of the false codling moth, Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae) and its implication for international trade.

The false codling moth (FCM), Thaumatotibia leucotreta (Lepidoptera: Tortricidae) is an insect pest which represents an important threat to the production and marketing of a wide range of agricultural crops in the African-Caribbean-Pacific (ACP) countries. The FCM reduces not only the yield and quality of the crop but also as a quarantine insect pest, restricts the trade of susceptible agricultural produce on the international market. In addition, little research has been conducted in the ACP countries on the bio-ecology and sustainable management of this pest, especially on vegetables for export. Thus, action-oriented research aimed at understanding the bio-ecology of this important pest is essential to achieve effective management. Various management interventions against this pest have been used in some parts of the world, especially in South Africa on citrus. Currently, farm sanitation is regarded as the key management strategy. Exploring and improving on other interventions such as Sterile Insect Technique, monitoring and mass trapping of male moths, augmentative biological control, use of bio-pesticides, protected cultivation and cold treatment may help to mitigate the expansion of FCM into other countries, especially in the European and Mediterranean Plant Protection Organization region where it has become a regulated insect pest since 2014. This review discussed the bio-ecology of FCM and highlighted some of the challenges and opportunities for its effective management and its implication for international trade, especially the export of chillies from the ACP countries into the European Union market which requires strict phytosanitary regulations.

Field Response of Cowpea, Vigna unguiculata Walper to Four Insecticidal Compounds and Their Residual Toxicity to Callosobruchus maculatus (F.) [Coleoptera: Chrysomelidae] in The Laboratory

There have been paradigm shift to the use of biopesticides as alternative to synthetic pesticides in recent years due to its environment friendliness and non-toxic to the non-target organisms. Therefore, three synthetic insecticides and water extract from neem back powder were evaluated on cowpea in the field and their residual toxicity tested against C. maculatus in the laboratory. The insecticides were applied at the rate of 2ml in 2L of water and 2L of extract from neem back powder on the field. The harvested seeds were infested with C. maculatus to evaluate the residual toxicity of the insecticides. Data on growth and yield parameters were taken on the field while data on adult mortality, oviposition, adult emergence and weight loss were recorded for the laboratory experiment. The results showed positive response of cowpea to the applied chemicals as they had higher values for the number of leaves, branches and reduced number of holes. Number of holes was significant (p< 0.05) at the 8th week with the control having highest number of holes. Cowpea treated with cypermethrin had highest number of pods at both 7th and 8th week and showed significant difference at 7th week. Highest weight of seeds per pod was obtained from the cowpea treated with water extract from neem back powder and was significantly different (p< 0.05) from other treatments. Seeds treated with the three insecticides had the same number of mortality while neem extract had highest but was not significantly different (p> 0.05). There was a reduction in number of eggs laid, adult emergence, seeds with holes and weight loss in the seeds treated with the four insecticide compounds. It was concluded that application of the insecticidal compounds positively enhanced the performance of cowpea on the field and could protect the seeds against C. maculatus in the laboratory. This study revealed that water extract from back powder of neem could be used as a botanical in the protection of cowpea against seed beetles.

Why don't smallholder farmers in Kenya use more biopesticides?

BackgroundAlthough Kenya has a relatively high number of registered biopesticide products, little is known about biopesticide use by smallholders. This paper documents farmers' current use and perception of chemical pesticides and biopesticides, their willingness to pay for biopesticides, and the key challenges to biopesticide uptake.ResultsA survey found that chemical pesticides are used widely by smallholders despite awareness of the risks to human health and the environment. Almost half of respondents showed awareness of biopesticides, but current use in the survey localities was low (10%). Key reasons for the low use of biopesticides by smallholders in this study are: perceptions of effectiveness, primarily speed of action and spectrum of activity, availability and affordability. Smallholders who used biopesticides cited effectiveness, recommendation by advisory services and perception of safety as key reasons for their choice. Although farmers viewed both pesticides and biopesticides as costly, they invested in the former due to their perceived effectiveness. Average willingness to pay, above current chemical pesticide expenditures per cropping season was 9.6% (US$5.7). Willingness to pay differed significantly between counties, and was higher among farmers with more education or greater awareness of the health risks associated with pesticide use.ConclusionThis study confirms the low use of biopesticide products in the survey areas, alongside high use of conventional chemical pesticides. In order to promote greater uptake of biopesticides, addressing farmers' awareness and their perceptions of effectiveness is important, as well as increasing the knowledge of those providing advice and ensuring registered products are available locally at competitive prices. © 2020 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

A Spinosad-Based Formulation Reduces the Survival and Alters the Behavior of the Stingless Bee Plebeia lucii.

The decline in bee populations worldwide has been associated with the use of pesticides in crop systems where these insects forage. The use of biopesticides, like spinosad, is preferred as an alternative method to control pests, because it is considered safer to non-target insects. In this study, we evaluated the lethal and sublethal effects of the spinosad-based formulation Tracer® on foragers of the stingless bee Plebeia lucii Moure (Apidae: Meliponini). Groups of bees were fed a pure diet (negative control) or a diet at different concentrations of spinosad. Positive control groups consisted of bees orally exposed to a diet with the neonicotinoid imidacloprid. Next, flight behavior, body mass, and respiration rate were evaluated in surviving bees. The results showed that bees´ survival was reduced by all concentrations of spinosad, when compared with the negative control. Bee locomotion-walking and flight-was reduced in accordance with the increase in spinosad concentrations; however, body mass and respiration rate were not altered. Our results show that the use of Tracer® in ecosystems visited by P. lucii can reduce forager bee survival and reduce their locomotion, generating a negative impact on pollination services provided by these bees.

Biopesticides in India: technology and sustainability linkages.

Despite enhancing the crop yields, the so called green revolution (GR) has proven unsuccessful in assuring long term agricultural sustainability. The methods used for productivity enhancement during GR have not only proven to be problematic but have also resulted in deterioration of soil quality and several other issues related to ecosystems and health issues. The damage was mainly caused by the indiscriminate use of chemical fertilizers and insecticides. Various types of pesticides, are now known to be causing huge problems in the agro-ecosystems. In such a situation, where chemicals have caused or are causing irreversible impacts on agroecosystems, the use of biopesticides has emerged as a sustainable alternative leading to safe organic farming. At the global level, environmentally benign nature and target-specificity of biopesticides are gaining wide popularity. However, in developing countries like India usage of biopesticides is still minuscule in comparison to conventional chemical pesticides. Although the Indian government has encouraged the use of biopesticides by placing them into many of the agricultural schemes, at the grassroots level, biopesticides are facing many challenges. The lower adaptability and declining interest of farmers towards biopesticides have become a matter of concern. However, technological challenges related to production, manufacture and application in agroecosystems have also raised a question on their long-term sustainability. The main objective of this review is to highlight the developing trend in the field of biocontrol products in India. Apart from this, the review also focuses on the technological perspectives that are required for the long-term sustainability of biological control products in Indian agriculture and market.

A socio-environmental perspective on pesticide use and food production.

Pesticides are part of a large group of organic compounds with different physicochemical characteristics, designed to control and prevent pests in various crops and plantations, improving productivity. This works provides a perspective on pesticide use in current agriculture with the aim of identifying the influence of pesticides on food production and their impact on the environment. Therefore, it is necessary to highlight the importance of determining pesticide residues in food, aiming to ensure food safety, since these compounds can represent risks to human health and the environment. The effects of pesticides on humans range from headaches, nausea and skin and eye irritation to chronic problems such as cancer and neurological disorders, and extend to other non-target organisms such as birds, fish and bees, contaminating water, soil, and plants, as opposed to the benefits of increased production, consequently other measures for pesticide consumption need to be evaluate to ensure human health, food safety and environmental protection. It is important to note that chromatographic techniques and mass spectrometry assist in the determination of pesticide residues and evaluate the quality of the food that reaches the consumer, and together with the Maximum Residue Limits (MRLs), established by the legislation of each country, these instrumentation act to control the exposure of population to pesticides. Although the MRL is used as a parameter for food quality, the global differences in pesticide legislation do not guarantee the consumer safety. In this sense, a brief analysis of MRL inefficiency is also present in this paper.

Farmers’ knowledge, perceptions and management of chili pepper anthracnose disease in Bangladesh

Plant diseases cause major crop yield losses and affect food security in lower-income countries. A limited understanding by farmers about the identity of plant diseases, transmission pathways and appropriate management methods is a key, but underexposed, problem. This study uses a sample of 260 farmers producing chili pepper in Bangladesh to elucidate their knowledge, perceptions and management methods regarding chili anthracnose—a fungal disease caused by Colletotrichum species. The results show that virtually all farmers had experienced typical symptoms of anthracnose disease and farmers reported average crop yield losses of 4%. Yet, only 22% of the farmers knew that this was a fungal disease and only 25% could tell how the disease spreads in the field. Farmers solely relied on chemical pesticides to control anthracnose, while the use of biopesticides, soil covers and crop rotations was negligible and only 7% of the farmers used labelled seed. A sound understanding of farmers of the crop diseases they face, their transmission pathways, and appropriate management methods is essential for establishing effective pest control. These results clearly show much room for improving chili productivity and the income and health of farmers, by building their capacity to deal with anthracnose disease.

Biopesticides as Promising Alternatives to Chemical Pesticides: A Review of Their Current and Future Status

Biopesticides are living organisms or natural products that control agricultural pests including bacteria, fungi, weeds, viruses and insects. Biopesticides can be classified into different categories, such as microbial pesticides, plant-incorporated protectants and biochemicals. Biopesticides are a crucial component of integrated pest management programs for pest control, which lead to more natural alternatives to chemical pesticides that are eco-friendly and safer. Since the emergence of biopesticides for potential pest management, numerous products have been released and some of them dominate the market. This review paper will discuss the current status, future prospect and challenges associated with the use of biopesticides in pest control.

Manufacturing of Granular Matrix with Diatomacious earth, Lime and Sugarcane Bagasse ash to Encapsulate Entomopathogenic Nematodes (Steinernema glaseri)

An alternative for pest control in corn production is the use of biopesticides formulated with entomopathogenic nematodes encapsulated in granular matrices. However, it has been observed that the granular matrices´ lack of resistance to handling and transport causes their deterioration, therefore limiting their use. This study analyzes the use of lime and sugarcane bagasse ash as stabilizer additives in granular matrices made of diatomite earth in order to improve the survival rate of Entomopathogenic Nematodes. Six formulations were prepared and evaluated at 3, 12, 21 and 30 days of age. A total of 192 granular matrices were produced, 144 for axial compressive strength testing and 48 for the estimation of the survival rate of the nematodes. In order to carry out the last test, Steinernema glaseri nematodes were encapsulated. The results indicate that the granular matrices made with the combination of 88% diatomaceous earth plus 6% lime and 6% sugarcane bagasse ash have adequate hardness (mechanical strength) for handling and transportation purposes; in addition, at 30 days of age the survival rate was the highest obtained when compared to the granular matrices of all tested formulations

Effect of biopesticides on different Tetranychus urticae Koch (Acari: Tetranychidae) life stages

Tetranychus urticae Koch management in many specialty crops relies on intensive pesticide use and has led to rapid evolution of acaricide-resistant populations. These concerns, along with public concern regarding conventional pesticide safety, has generated interest in the use of biopesticides for managing T. urticae. Biopesticides evaluated included the bacterial products Grandevo DF 2 (Chromobacterium subtsugae strain PRAA4-1) and Venerate EP (Burkholderia spp. strain A396), the botanical-based product GOS Neem 7-way (azadirachtin), and the emulsified mineral oil product TriTek. Bifenazate (Acramite 50WP), a synthetic acaricide, and a water-treated control were included for comparative purposes. Contact and residual effects were evaluated using equivalent labeled field rates against T. urticae egg, larval, nymphal and adult life stages. Exposure route (contact or residual) was significant for eggs and larval and nymphal mortality after 24-h exposure. GOS Neem 7-way, TriTek, and Acramite were ovicidal under contact exposure only. Most biopesticides caused >50% larval mortality, yet only Acramite achieved 100% morality. Biopesticides were less toxic to nymphs relative to larvae, and Acramite and Grandevo DF 2 caused >50% nymphal morality. Only Acramite caused significantly higher adult mortality than the control 24-h post treatment. Except for Venerate, all treatments significantly reduced fecundity of surviving adults, with the greatest reduction by Acramite and Grandevo. With the exception of Acramite and a high rate of Grandevo, all treatments exhibited exponential population growth over five generations. However, most biopesticides evaluated exhibited significant mortality on various T. urticae life stages, and if incorporated into management schemes may be useful tools in acaricide resistance management programs for T. urticae.

Deciphering the associated risk on soil microbes upon use of biopesticides in rice ecosystem.

Plant species, viz Cleistanthus collinus, Lantana camara, and Strychnos nux-vomica are being traditionally used for pest management in rice. However, limited investigation has been carried out to understand the toxic effect of these materials on soil microbes. Hot water extracts of these plants were evaluated for their effects on soil microbial population and enzyme activities along with neem oil and chlorpyrifos as check. Soil microbial population, viz bacteria, fungi, phosphate-solubilizing bacteria (PSB), and asymbiotic nitrogen fixers were unchanged after application of plant extracts. Maximum population of bacteria including PSB and asymbiotic nitrogen fixers were observed in control, whereas, S. nux-vomica, and C. collinus-treated soil had higher number of actinomycetes and fungal population, respectively. Soil microbial biomass did not vary differently among the plant extracts. Application of plant extracts did not alter dehydrogenase, β-glycosidase, acid phosphatase, alkaline phosphatase, and urease content in soil. Secondary metabolites present in these plant extracts may be responsible for variable effects on soil microbes. Chlorpyrifos had a fleeting negative effect on soil microbes and enzymes in comparison to plant extracts. All the three plants did not have any negative effect on soil microbes and enzymes and can be safely recommended in rice pest management.

Efficacy of Bacillus thuringiensis and Beauveria bassiana Against Red Palm Weevil Rhynchophorus ferrugineus Olivier (Coleoptera: Curculionidae)

The use of bio-pesticides is the potential alternate of synthetic residual insecticides to cope with the problem of resistance among different insect pests while posing no threats to the environment and biological control agents. Laboratory trials were conducted in the Microbial Control Laboratory, Department of Entomology, University of Agriculture, Faisalabad (UAF), Pakistan, during 2017–18 to investigate the effect of Beauveria bassiana (Balsamo) Vuillemin (1.8 × 107 and 1.8 × 108 conidia/ml) and Bacillus thuringiensis (Berliner) at a dose rate of (0.5 and 1 µg/g) alone and in combination against fifth and sixth larval instars of Rhynchophorus ferrugineus Olivier (Curculionidae: Coleoptera). The insects were exposed to fungal and bacterial treatments by larval immersion and diet incorporation method, respectively. Results revealed that the combined application of B. bassiana at the rate of 1.8 × 108 conidia/ml and B. thuringiensis at 0.5 and 1 µg/g exhibited synergistic effects, while combination of lower fungal concentration with both dose rates of B. thuringiensis showed additive effect against target instars of R. ferrugineus. Moreover, the mortality data showed that fifth instar larvae were more susceptible to microbial treatments than sixth instar. Maximum mycosis and sporulation was recorded in the cadavers of R. ferrugineus where B. bassiana was applied individually at dose rate of 1.8 × 107 conidia/ml. The present work suggests that B. bassiana in combination with B. thuringiensis could be a cost–benefit strategy against R. ferrugineus on date palms.

Perception on biological pesticide by various levels of stakeholders in Nepal

Government of Nepal (GoN) has been prioritizing Integrated Pest Management (IPM) strategy as the most important strategy after a sudden outbreak of Brown Plant Hopper (BPH) and heavy loss in rice production. GoN has been continuing IPM programs with the successful completion of different phases like technical cooperation, marketing and institutionalization. Awareness creation among multisectoral stakeholders is the most and major outcome through IPM program in Nepal. Plantwise, a global program led by CABI, has been working with GoN since 2013, for the improvement of plant health system. This program has also a good impact in the promotion of nonchemical strategies of pest management. Despite of having many national programs, efforts of GoN as well as different non-governmental and community based organizations; a significant progress has not been seen in the use of biological pesticides. This paper has tried to analyze the role of different stakeholders in the promotion of bio-pesticides along with other non-chemical management strategies viz. the trend of recommendations by plant doctors with the information retrieved from Plantwise Online Management System (POMS), perception of farmers as well as agro-input suppliers to the bio-pesticides, plant clinic interventions for bio-pesticides promotion, and policy review for finding reasons for less use of bio-pesticides in the field. Around 200 farmers who visited plant clinics and 50 agro-inputs suppliers from different regions were randomly selected for the survey with the developed questionaire. This paper is a preliminary review of secondary information on relevant policies, acts, regulations, etc. Major problem has been observed in agro-input suppliers among the whole cycle of biopesticide use.