Chemical Insecticides Research Articles

Assessments of some animal bones biochar as paddy protectants against rice weevil, Sitophilus oryzae L. [Coleoptera: Curculionidae]

The main insect pest of stored paddy is Sitophilus oryzae (rice weevil). Huge amounts of rice are produced by peasant farmers each year, but the bulk of it is wasted due to insufficient storage facilities and insect pest attacks brought on by careless handling. In this study, the insecticidal effects of biochar on S. oryzae were assessed in femurs from Sus scrofa (pig), Gallus gallus (chicken), and Bos taurus (cattle). Adult mortality, adult emergence, weight loss, seed damage, and weevil perforation index are among the indicators evaluated. To apply the biochar, different dosages were used: 0.2, 0.4, 0.6, 0.8, and 1.0 g/20 g of paddy rice. In this work, the population of adult S. oryzae on paddy rice was dramatically reduced by all animal bones biochar tested for insecticidal activity (p < 0.05). The animal bone biochar became more effective with increasing dosage. After 24 h of treatment, pig biochar induced a 36.67 % mortality rate of adult S. oryzae, followed by cow biochar's 20 % mortality rate of rice weevils. The fatal dose of cattle, pig, and chicken biochar at which 50 % (LD50) of the population of adult S. oryzae responded after 24 h of treatment were 0.83g, 0.43g, and 0.90g, respectively. It should be encouraged to utilize biochar made from animal bones to combat the S. oryzae in stored paddy. They could be utilized as a green control measure to lessen the risk brought on by the usage of synthetic chemical insecticides in the environment.

Characterization of Indigenous Bacillus thuringiensis Isolates and Toxicity Analysis Against Brinjal Shoot and Fruit Borer, Leucinodes orbonalis (Guenee)

The toxins derived from Bacillus thuringiensis (Bt) exhibit significant promise in managing specific orders of harmful insects without the drawbacks in using of chemical insecticides. This study examines 20 indigenous Bt isolates, with a focus on their colony and crystal morphology, gene content, protein profiles, and toxicity against the larvae of Leucinodes orbonalis. The results revealed that all colonies were creamy white in colour with fried egg type appearance, flat surface, and undulated margin with spherical shaped crystals. PCR screening detected the existence of cry1, cry2, and vip3A genes with varying gene combinations among the isolates. Protein profiles exhibited the presence of multiple proteins with molecular weights ranging from 20 to 135 kDa, particularly ~135 and ~65 kDa represents Cry1 and Cry2 protein. In vitro bioassays against L. orbonalis revealed that four isolates T193, T339, T374, and T380 having substantial toxicity (93.33 to 100% mortality), suggesting the potential for their utilization in sustainable pest management strategies.

Phytochemical Characterization of Callistemon lanceolatus Leaf Essential Oils and Their Application as Sustainable Stored Grain Protectants against Major Storage Insect Pests

Food storage has been important since the dawn of agriculture and human settlement. Insect pests cause major losses to food grains during storage and production. Essential oils are good alternatives for chemical insecticides for the management of storage pests. Red bottlebrush, Callistemon lanceolatus, is a flowering plant of the Myrtaceae family. This research work aimed to extract the oil from bottlebrush leaves, and chemically characterize and assess their repellent and insecticidal properties against the cowpea seed beetle, Callasobruchus maculatus (F.) (Coleoptera: Chrysomelidae), cigarette beetle, Lasioderma serricorne (F.) (Coleoptera: Ptinidae), and red flour beetle, Tribolium castaneum (Herbst.) (Coleoptera: Tenebrionidae), for the first time. The essential oil yielded by hydro-distillation of bottlebrush leaves was 1.02 ± 0.01%. GC-MS analysis determined the chemical composition of the volatile oil comprised 1,8-cineole (19.17%), α-terpineol (11.51%), α-pinene (10.28%), and α-Phellandrene (9.55%). The C. lanceolatus leaf oil showed potent repellence, contact toxicity, and fumigation toxic effects. In the contact toxicity assay, at 24 h, the LC50 values were 1.35, 0.52, and 0.58 mg/cm2 for the red flour beetle, cigarette beetle, and cowpea seed beetle, respectively. Likewise, in the fumigation assay observed after 24 h, LC50 values of 22.60, 5.48, and 1.43 µL/L air were demonstrated for the red flour beetle, cigarette beetle, and cowpea seed beetle, respectively. Additionally, there was no significance found by a phytotoxicity assay when the paddy seeds were exposed to C. lanceolatus oil. The results show that the volatile oils from red bottlebrush leaves have the potential to be applied as a biopesticide. Therefore, C. lanceolatus leaf oil can be utilized as a bio-insecticide to control stored product insects.

Defense Responses of Different Rice Varieties Affect Growth Performance and Food Utilization of Cnaphalocrocis medinalis Larvae

Rice leaf folder, Cnaphalocrocis medinalis (Guenée), is one of the most serious pests on rice. At present, chemical control is the main method for controlling this pest. However, the indiscriminate use of chemical insecticides has non-target effects and may cause environmental pollution. Besides, leaf curling behavior by C. medinalis may indirectly reduce the efficacy of chemical spray. Therefore, it is crucial to cultivate efficient rice varieties resistant to this pest. Previous studies have found that three different rice varieties, Zhongzao39 (ZZ39), Xiushui134 (XS134), and Yongyou1540 (YY1540), had varying degrees of infestation by C. medinalis. However, it is currently unclear whether the reason for this difference is related to the difference in defense ability of the three rice varieties against the infestation of C. medinalis. To explore this issue, the current study investigated the effects of three rice varieties on the growth performance and food utilization capability of the 4th instar C. medinalis. Further, it elucidated the differences in defense responses among different rice varieties based on the differences in leaf physiological and biochemical indicators and their impact on population occurrence. The results showed that the larval survival rate was the lowest, and the development period was significantly prolonged after feeding on YY1540. This was not related to the differences in leaf wax, pigments, and nutritional components among the three rice varieties nor to the feeding preferences of the larvae. The rate of superoxide anion production, hydrogen peroxide content, and the activity of three protective enzymes were negatively correlated with larval survival rate, and they all showed the highest in YY1540 leaves. Compared to other tested varieties, although the larvae feeding on YY1540 had higher conversion efficiency of ingested food and lower relative consumption rate, their relative growth was faster, indicating stronger food utilization capability. However, they had a lower accumulation of protein. This suggests that different rice varieties had different levels of oxidative stress after infestation by C. medinalis. The defense response of YY1540 was more intense, which was not conducive to the development of the larvae population. These results will provide new insights into the interaction mechanism between different rice varieties and C. medinalis and provide a theoretical basis for cultivating rice varieties resistant to this pest.

Synthesis, toxicological and in silico evaluation of novel spiro pyrimidines against Culex pipiens L. referring to chitinase enzyme

The exponential development of resistance to conventional chemical insecticides adds another important motive for the creation of novel insecticidal active agents. One of the keys to meeting this challenge is the exploration of novel classes of insecticidal molecules with different modes of action. Herein, a novel series of spiro pyrimidine derivatives was prepared using some green synthetic methodologies such as microwave irradiation, and sonication under ultrasound waves. Spiro pyrimidine aminonitrile 1 is a key starting material for the synthesis of targets 2–9 by reaction with different carbon electrophiles and nitrogen nucleophiles. The structures of all the newly synthesized compounds were approved using spectral data. The toxicological efficiency and biological impacts of the synthesized spiro pyrimidine derivatives were assessed against Culex pipiens L. larvae. The toxicity of synthesized compounds showed remarkable variations against the C. pipiens larvae. Where, 3, 4 and 2 were the most efficient compounds with LC50 values of 12.43, 16.29 and 21.73 µg/mL, respectively. While 1 was the least potent compound with an LC50 value of 95.18 µg/mL. As well, other compounds were arranged according to LC50 values as follows 5 > 7 > 6 > 9 > 8. In addition, 3 and 4 exhibited significant prolongation of the developmental duration and greatly inhibited adult emergence. Moreover, many morphological deformities were observed in all developmental stages. Furthermore, cytotoxicity of the most effective compounds was assessed against the normal human cells (WI-38) as non-target organisms, where compounds 2, 4 and 3 showed weak to non-toxic effects. The study of binding affinity and correlation between chemical structure and reactivity was carried out using molecular docking study and DFT calculations to investigate their mode of action. This study shed light on promising compounds with larvicidal activity and biological impacts on the C. pipiens life cycle.

Influence of temperature combined with photodynamic inactivation on the development of Aedes aegypti

To reduce the speed of selection of populations resistant to chemical insecticides, photodynamic inactivation (PDI) against Aedes aegypti is a hot-topic and promising alternative technique to vector control. Temperature is an important factor in the survival of Ae. aegypti larvae and mosquitoes as it influences physiology, behavior, and ecology. This work aimed to evaluate parameters of the biological cycle of Ae. aegypti such as: hatching rate, larval development, adult mosquito longevity, sex ratio, weight, and lethal concentration of larval mortality (LC) through the combination of PDI with different temperatures. The number of larvae found after 48 h suggests that temperature affects hatching rate. Additionally, results showed a delay in development of surviving larvae after PDI when compared to control groups, and there was a reduction in the longevity of mosquitoes that undertook photodynamic action. PDI also led to a predominance of male insects, and observed weight indicates that the inactivation method may have also interfered in mosquito size. The results point to a satisfactory performance of PDI at all tested temperatures. Experimental conditions that were not lethal to all larvae implied that PDI impacts the mosquitoes’ biological cycle. Though metabolism and development are improved at higher temperatures, so is PDI action, thus maintaining the net benefit. Therefore, it is assumed that the proposed photolarvicide can be useful in reducing arbovirus transmission, and results invite for future research in different abiotic conditions.

MS Binding Assays with UNC0642 as reporter ligand for the MB327 binding site of the nicotinic acetylcholine receptor

Intoxications with organophosphorus compounds (OPCs) based chemical warfare agents and insecticides may result in a detrimental overstimulation of muscarinic and nicotinic acetylcholine receptors evolving into a cholinergic crisis leading to death due to respiratory failure. In the case of the nicotinic acetylcholine receptor (nAChR), overstimulation leads to a desensitization of the receptor, which cannot be pharmacologically treated so far. Still, compounds interacting with the MB327 binding site of the nAChR like the bispyridinium salt MB327 have been found to re-establish the functional activity of the desensitized receptor. Only recently, a series of quinazoline derivatives with UNC0642 as one of the most prominent representatives has been identified to address the MB327 binding site of the nAChR, as well. In this study, UNC0642 has been utilized as a reporter ligand to establish new Binding Assays for this target. These assays follow the concept of MS Binding Assays for which by assessing the amount of bound reporter ligand by mass spectrometry no radiolabeled material is required. According to the results of the performed MS Binding Assays comprising saturation and competition experiments it can be concluded, that UNC0642 used as a reporter ligand addresses the MB327 binding site of the Torpedo-nAChR. This is further supported by the outcome of ex vivo studies carried out with poisoned rat diaphragm muscles as well as by in silico studies predicting the binding mode of UNC0646, an analog of UNC0642 with the highest binding affinity, in the recently proposed binding site of MB327 (MB327-PAM-1). With UNC0642 addressing the MB327 binding site of the Torpedo-nAChR, this and related quinazoline derivatives represent a promising starting point for the development of novel ligands of the nAChR as antidotes for the treatment of intoxications with organophosphorus compounds. Further, the new MS Binding Assays are a potent alternative to established assays and of particular value, as they do not require the use of radiolabeled material and are based on a commercially available compound as reporter ligand, UNC0642, exhibiting one of the highest binding affinities for the MB327 binding site known so far.

The efficacy of some synthetic monoterpenes and Yucca extract for controlling Tribolium castaneum (Herbst) in wheat grain

The study’s objective was to assess the efficacy and to identify the toxic mechanisms of action of some plant-derived monoterpenes and yucca extract as alternatives to chemical insecticides against the red flour beetle, Tribolium castaneum. Carvone, 1,8-cineole, cuminaldehyde, and linalool, as well as Yucca schidgera extract, were the control agents whose efficacy against the red flour beetle was tested in the laboratory and compared to malathion. The criteria for evaluating efficacy were the effects of the tested compounds on adult mortality and red flour beetle progeny. Furthermore, the effects of the control agents on some enzymes (Acetylcholinesterase, ά-amylase, and alkaline phosphatase) in T. castaneum were investigated. Moreover, the effect of the tested control measures on weight loss of treated wheat grain was studied. The tested substances showed a high ability to control T. castaneum with regard to adult mortality and offspring production, especially when used as fumigants. For adult mortality, malathion showed the highest potential against T. castaneum as a fumigant, followed by carvone, yucca extract, cuminaldehyde, linalool, and 1,8-cineole with LC 50 values of 0.05, 331.5, 365.1, 372.2, 460, and 467.5 mg · 1000 cm –2 after 72 hours, respectively. The highest reduction in progeny was for malathion followed by carvone, linalool, cineole, yucca extract, and cuminaldehyde with reduction percentages of 100, 90, 89.3,79.4 and 65.8%, respectively. The tested compounds significantly affected acetylcholinesterase activity, alpha-amylase activity, and alkaline phosphatase in the red flour beetle. There was no significant reduction in the weight of wheat grains treated with the tested materials compared to the untreated healthy grains. Finally, the tested compounds as fumigants, especially 1,8-cineole, can be considered as effective alternatives to control the red flour beetle.

Efficacy of plant products in controlling disease vector mosquitoes, a review

AbstractMosquitoes pose a severe threat to the environment as vectors of numerous harmful diseases affecting humans and animals. Mosquitoes transmit pathogens that cause dengue, chikungunya, malaria, zika, yellow fever, Japanese encephalitis, and filariasis. Today's mosquito control strategies heavily rely on the use of chemical insecticides such as N,N‐diethyl‐meta‐toluamide (DEET), N,N‐diethyl mandelic acid amide (DEM), and dimethyl phthalate (DMP). However, the widespread use of chemical insecticides has resulted in pollution, bio‐magnification, and other health and environmental issues. It has also become ineffective because of the mosquitoes' aptitude to develop resistance, emphasizing the urgent need for safe, effective, and long‐lasting strategies. An alternative and promising approach to circumventing these obstacles involves the implementation of insecticides made from natural compounds found in plants. Therefore, the scientific community has shifted its focus towards plant‐based phytochemicals, oils, and extracts, as these are eco‐friendly, safe, and cost‐effective alternatives to conventional chemical insecticides. This review aims to provide details on current advances in plant‐based products (plant compounds, extracts, and essential oils), which are used to control all the life cycle stages (egg, larva, pupa, and adult) of the mosquito genera Aedes, Anopheles, and Culex. Hopefully, this review will pave the way to devise control strategies against these challenging pests.

Diverse Approaches to Insect Control: Utilizing Brassica carinata (A.) Braun and Camelina sativa (L.) Crantz Oil as Modern Bioinsecticides

The forest environment is exposed to a number of harmful factors that significantly reduce the resistance of forest stands, often leading to their extinction. In addition to abiotic and anthropogenic factors, biotic factors pose a significant threat to forests, among which insect pests are at the top of the list. Until now, the use of chemical insecticides has been considered the most effective method of pest control, resulting in pesticide residue in the environment. In an effort to minimize the harmful effects of insecticides, the European Union (EU), through EU Commission Implementing Regulations 2022/94, 2021/2081, 2021/795, and 2020/1643, has decided to withdraw from use a number of preparations containing compounds such as phosmet, indoxacarb, alpha-cypermethrin, and imidacloprid, among others. Botanical insecticides appear to be a promising alternative. Among them, plant oils and essential oils have become an innovative solution for controlling pests not only of forests but also of agricultural crops. The purpose of this literature review was to select oilseed plants with great biological potential. The rich chemical compositions of the seeds of Brassica carinata (A.) Braun and Camelina sativa (L.) Cranz predispose them to use as raw materials for the production of biopesticides with broad mechanisms of action. On the one hand, the oil will provide a physical action of covering pests feeding on a plant with a thin film, which will consequently lead to a reduction in gas exchange processes. On the other hand, the bioactive compounds in it or extracts of fat-insoluble compounds suspended in it and derived from the pomace fraction may have deterrent or lethal effects. This paper presents evidence of the potential action of these raw materials. Preparations based on these oils will not pose a threat to living beings and will not negatively affect the environment, thus allowing them to gain social acceptance.

Influence of fall armyworm Spodoptera frugiperda egg mass scales and layers on the performance of three species of egg parasitoid Trichogramma with different ovipositor lengths

BackgroundThe fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) is a highly polyphagous and destructive pest of maize and other cereal crops. Biological control is a potential alternative to chemical insecticides used for the management of FAW in maize. Egg parasitoids are promising biocontrol agents as they kill the insect pest at their egg stage before it hatches, thus preventing the damaging larval stage. Trichogramma is widely used in augmentative biological control of FAW in native and invaded regions. However, FAW lay egg masses in layer by layer and eggs are covered with egg scales, this may affect the performance of Trichogramma parasitoids. Therefore, the parasitism potential of three Trichogramma species was studied on eggs with or without scales and layered eggs of FAW, further the impact of parasitoids ovipositor length on parasitism was also determined. This helps to understand the parasitism potential of parasitoids on different egg type for better implementation of biological control programs against FAW.ResultsThe effect of FAW egg mass with or without scales and layered eggs on the performance of Trichogramma chilonis, T. pretiosum and T. mwanzai was studied and results indicated that egg mass scales and the layered eggs were significantly affected the parasitism potential of Trichogramma species, but did not affect the parasitoid emergence. In general, T. chilonis parasitized a higher percentage of eggs with or without scales and layered eggs of FAW than the other two species. T. chilonis and T. mwanzai had a greater ovipositor length than T. pretiosum.ConclusionThe performance of evaluated Trichogramma species on FAW eggs with or without scales and layered eggs affected the parasitism success. The parasitism success of T. chilonis was comparably higher than other tested species. Hence, the scales on egg masses and layered eggs of FAW should be taken into account while selecting the Trichogramma species in the biological control of FAW.

Exploring bioactive molecules with fumigation toxicity against the red imported fire ant Solenopsis invicta Buren from commercial essential oils by GC–MS combined with chemometrics

Metabolomics approaches are becoming a powerful analytical technique for exploring bioactive molecules in essential oils. The prevalence of imported red fire ants affected the environment, biodiversity of wildlife, infrastructure, and hypersensitivity reactions of people. Due to public health and environmental issues, essential oils as environmentally friendly alternatives to synthetic chemical insecticides in fire ant management have attracted great attention. However, there is a lack of an objective strategy suitable for identifying bioactive molecules that can guarantee the quality of essential oil biopesticides. Therefore, a metabolomics approach with four main steps, including bioassays, GCMS analysis of chemical constitution, construction of multivariate OPLS and univariate Pearson correlation statistical models, and feature selection, was proposed in this study to verify its potential to find bioactive molecules in essential oils that are effective against red imported fire ants. The fumigation mortalities of 20 commercial essential oils ranged from 0 to 100%. A total of 296 mass features were deconvoluted, and 121 of them were identified. Then, 52 potential bioactive molecules were selected by both VIP > 1.0 and P < 0.05. Finally, 6 of these potential bioactive molecules, (+)− 2-bornanone,.beta.-pinene, eucalyptol, isoborneol, linalool, and L-.alpha.-terpineol, have shown good fumigation toxicity against minor and/or major red imported fire ant workers. This study has, in certain aspects, supported the feasibility of this metabolomics approach. It could be helpful for natural molecules to be alternatives to synthetic chemical insecticides, leading to more environmentally friendly and sustainable management policies for red imported fire ants.

EFFECTIVENESS OF MAJA FRUIT EXTRACT (Aegle marmelos) AS AN ALTERNATIVE FOR PEST CONTROL LIVING LOCKS (Locusta migratoria)

Background: Control of wandering grasshoppers at the farmer level generally uses chemical insecticides which can damage non-target organisms, pest resistance, pest resurgence and cause residual effects Methods: Laboratory experimental research, although it can also be carried out outside the laboratory, its implementation applies laboratory principles. Results: The effectiveness of the mortality of maja fruit extract on wandering grasshoppers, in the treatment of giving 40% maja fruit extract, there was an increase in the number of deaths of wandering grasshoppers, where in the 10th minute there was 20% death, there had already been deaths compared to the treatment giving 20% extract with the same amount. wandering grasshoppers died by 100%. Conclusion: Maja fruit extract (Aegle marmelos), has the power to kill wandering grasshoppers (Locusta migratoria) because it contains tannins and saponins which are toxic and have a real effect in killing wandering grasshoppers

Efficacy of microbiological and chemical insecticides as alternatives for control of Myochrous armatus (Baly, 1865) (Coleoptera: Chrysomelidae).

Myochrous armatus (Baly, 1865) (Coleoptera: Chrysomelidae) causes considerable losses to soybean crops in Brazil and several other South American countries. Applying biological insecticides can be an effective alternative to suppressing this pest. The objective of this study was to assess the efficacy of microbiological insecticides formulated from the fungi Beauveria bassiana + Metarhizium anisopliae (Bometil) and B. bassiana alone (Ballvéria), and the bacterium Bacillus thuringiensis (Acera) alone and in combination with the chemical insecticides fipronil, ethiprole and chlorpyrifos, against M. armatus adults. The insecticides based on B. bassiana + M. anisopliae were found to be more pathogenic than those based on B. bassiana, causing cumulative mortality rates in the ten days of 85.0 and 65.0% respectively. In contrast, B. thuringiensis caused 92.5% mortality. These products alone and in combination were effective for control at their lowest concentrations. Therefore, the use of microbiological insecticides individually or in combination with chemical insecticides is a promising alternative for the integrated management of M. armatus.

Biorational methods for effective pest control management in stored products for agricultural sustainability

AbstractStorage grain infestation is a critical problem, with insect pests and rodents causing economic losses and reductions in the quality of food grains and food products. It has been assessed as affecting 9% of goods in developed countries and more than 20% of goods in developing countries. The chemical insecticides used for storing products protect against insect pests, but introduce hazards associated with handling insecticides and the residues on food, which threaten nontarget organisms, and so represent a serious problem to the environment. Biorational methods are low risk, are obtained from animals, plants, bacteria and some minerals, and are segregated into microbial, plant‐associated protectant and biochemical substances. This method encompasses temperature management, modified atmospheric storage, ionizing irradiation, the mixing of inert materials, pheromone traps, botanicals, insect growth regulators, entomopathogens and host plant resistance. Biorational methods have emerged as alternative or supplemental pest control methods. Biopesticides would help in preventing the use of large quantities of pesticides across the globe, thus providing residue‐free food and a safe environment for living. Further investigation is needed to integrate these elements to enhance the efficacy, minimize the losses and diminish the reliance on pesticides for the preservation of stored commodities.

Comparative efficacy of selected botanicals and chemical insecticide against pea pod borer Etiella zinkenella (Tr.) in pea at trance region of Yamuna, Prayagraj

Comparative efficacy of selected botanicals and chemical insecticide against pea pod borer Etiella zinkenella (Tr.) in pea at trance region of Yamuna, Prayagraj

Comparative field efficacy of biopesticides and chemical insecticides against pea leaf miner, Chromatomyia horticola (Goureau) on pea (Pisum sativum L.)

Comparative field efficacy of biopesticides and chemical insecticides against pea leaf miner, Chromatomyia horticola (Goureau) on pea (Pisum sativum L.)

Management of mulberry thrips through chemical insecticides

Management of mulberry thrips through chemical insecticides

A review on strategies for managing sucking insect pests in Indian grain legumes with chemical insecticides

A review on strategies for managing sucking insect pests in Indian grain legumes with chemical insecticides

Evaluation of New Chemistry Insecticides against Sucking Insect Pests of Cotton

Evaluation of New Chemistry Insecticides against Sucking Insect Pests of Cotton