Effects Of Insecticides Research Articles

Lethal and sublethal effects of various insecticides on the immature stages of the solitary egg parasitoid, Telenomus busseolae

Telenomus busseolae Gahan (Hymenoptera: Scelionidae) is the most effective egg parasitoid of corn borers, Sesamia spp. (Lepidoptera: Noctuidae). A balanced pest management requires the use of insecticides compatible with T. busseolae since relying solely on the parasitoid may prove inadequate in controlling pest outbreaks. This study investigated the lethal and sublethal effects of chlorantraniliprole, imidacloprid, indoxacarb, lambda-cyhalothrin, lufenuron, malathion, and thiamethoxam + lambda-cyhalothrin, at various concentrations on emergence rate and fecundity of treated generation as well as emergence rate and sex ratio of offspring generation. The experiments were performed by immersing the host eggs with the parasitoid, encompassing its early larval, late larval, and pupal stages into the insecticide solutions.All concentrations of the insecticides reduced emergence rate in the treated generation, with the pupal stage being most vulnerable except for controversial effects of lambda-cyhalothrin and immature stage-independent effects of imidacloprid. The insecticides, at least one of the concentrations, negatively affected parasitoid fecundity regardless of a consistent pattern across immature stages. The insecticides did not affect the tested attributes of offspring generation except for that imidacloprid reduced female offspring numbers, and malathion decreased emergence rates.This study provides insights into immature stage-specific susceptibility and fecundity responses of treated generation along with potential impacts on subsequent generation, highlighting the necessity of prudent insecticide usage within the context of integrated pest management strategies (IPMs) in maize fields. Additionally, it underscores the urgency of performing field studies to ascertain actual toxicological scenarios.

Bio-Efficacy of Different Insecticides Against Soybean Leaf Folder, Omiodes indicata (Fabricius, 1775) (Lepidoptera: Crambidae)

A study was conducted at the Agricultural Research Station (UAS, Dharwad), Sankeshwar, Karnataka during Kharif 2022-23 to assess the effectiveness of different insecticides against soybean leaf folder, Omiodes indicata. Among five treatments, lambda cyhalothrin 4.6 % + chlorantraniliprole 9.3 % ZC @ 0.4 ml l-1 exhibited the lowest mean population of soybean leaf folder, Omiodes indicata on 5th and 10th day after spray with 2.12 and 0.98 larval population per meter row length, respectively which was followed by emamectin benzoate 5 % SG @ 0.3 g l-1 (3.03 and 1.83 larvae per meter row length). Lambda cyhalothrin 4.6 % + chlorantraniliprole 9.3 % ZC was found to be the best effective treatment with 81.97 % reduction over control followed by emamectin benzoate 5 SG (71.61 %). Similar results were obtained with per cent defoliation.

Insecticidal, biochemical and histological effects of monoterpenes against Musca domestica (Diptera: Muscidae)

The insecticidal activity of ten monoterpenes against larvae of Musca domestica (Diptera: Muscidae) was evaluated. Monoterpenes were mixed with food-media at concentrations of 2.5, 5.0, 10.0, 25.0, 50.0, 75.0 and 100.0 mg/kg. Three monoterpenes, p-cymene, 1,8-cineole and cuminaldehyde displayed a durable larvicidal activity with LC50 values of 0.14, 1.59 and 1.90 mg/kg 3 days post treatment. The three monoterpenes were more toxic than deltamethrin (LC50 = 3.36 mg/kg). Likewise, monoterpenes induced a significant reduction in pupation and adult emergence. Cuminaldehyde at 25.0 mg/kg, and p-cymene, 1,8-cineole and citronellal at 50.0 mg/kg caused a complete inhibition of pupation and adult emergence. Also, p-cymene at 25.0 mg/kg reduced the activity of larval amylase and lipase, while 1,8-cineole and cuminaldehyde increased their activity. Cuminaldehyde and α-terpinene inhibited the activity of proteases whereas p-cymene enhanced their activity. In the case of acetylcholinesterase, general-esterase and adenosinetriphosphatase, p-cymene and 1,8-cineole induced enzyme inhibition and citronellal increased enzyme activities. Finally, the tested monoterpenes caused histological changes on treated larvae, such as the basement membrane appeared and the epithelium cells deformed in some points and seen filled with scattered vacuoles. These findings indicate that the tested monoterpenes have a potential to be applied in IPM programs of M. domestica.

Insecticidal effect of new synthesized chalcone derivatives on Caribbean fruit fly, Anastrepha suspensa.

In this present study, new chalcone derivatives were synthesized from 4-aminoacetophenone, which were confirmed by spectroscopic methods. The toxic risks of chalcones to humans and the environment were investigated by a web-based platform called ADMETlab. With this program, the possible toxic effects of the compounds on liver, respiratory system, and eyes were evaluated. For the topical insecticidal activity, adult female Caribbean fruit fly, Anastrepha suspensa, was targeted. Results of the toxicity tests showed that chalcone derivatives are effective against female A.suspensa. Among the synthesized chalcones, 1-(4-cinnamoylphenyl)-3-(p-tolyl)urea (2) exhibited the greatest insecticidal activity, resulting in 73 % mortality at 100 µg/fly after 24 h, whereas other derivatives showed less than 30 % mortality. Our results demonstrate that insecticidal activity may be modulated by the presence of a certain phenyl ring in the structure of derivative 2 and, therefore, has potential for design of efficient chemicals for tephritid fruit fly management.

Efficacy assessment of different insecticides for control of whitefly against tomato leaf curl disease

AbstractThe impact of eight pesticides on the transmission of Tomato leaf curl virus (ToLCV) by the whitefly, Bemisia tabaci Gennadius to tomato, Lycopersicon esculentum (Miller), was studied in the field using a randomized block design. Differences in performance were anticipated because these eight insecticides comprise distinct mechanism of action including both contact and systemic. Increased insecticide efficacy is necessary, particularly in regions with conducive weather conditions that support a healthy whitefly population, to effectively manage the population. There is a need to vary the insecticides used in order to reduce the emergence of resistance in the whitefly population due to the extensive usage of a single mechanism of action for whitefly control. The foliar spray of insecticides was done when first incidence of whitefly was noticed in the field with 15 days of interval. The studies on effect of different insecticides in the management of ToLCV disease through the controlling whitefly population, we evaluated that Chlorantraniliprole 8.8% + Thiomethaxam 17.5% SC was effective in sustaining the yield by reducing the incidence of disease and whitefly population during both the years followed by Spirotetramat 11.01% + Imidacloprid 11.01% SC, Thiamethoxam 12.6% + Lambda cyhalothrin 9.5% ZC and Cyantraniliprole 10.26% OD, respectively.

Assessing the potential of nano-formulated chlorfenapyr and clothianidin insecticides-treated sugar baits against Anopheles funestus, Anopeles coluzzii and Culex quinquefasciatus mosquitoes

Mosquitoes serve as vectors for various diseases like malaria, dengue fever, yellow fever, and lymphatic filarial diseases causing significant global health problems, highlighting the importance of vector control. The study was conducted to assess the effectiveness of nanoformulated clothianidin and chlorfenapyr insecticides treated with ATSB in controlling three mosquito strains. The development of a natural thiolated polymer-coated ATSB nano formulation involved incorporating nano-carriers to deliver insecticides. Field- collected mosquito strains were subjected to laboratory-based bioassays using 1 % and 1.5 % concentrations of each conventionally used and nanoformulated insecticide with ATSB solution. Adult mosquitoes were left overnight to contact with N-ATSB and efficacy was recorded after 36 and 72 h. The results showed that nanoformulated chlorfenapyr was significantly more effective as compared to clothianidin against An. funestus and Cx. quinquefasciatus but the results were not significantly different against An. coluzzii (100 %). An. coluzzii was found to be the most susceptible strain followed by An. funestus and showed 100 % and ∼ 98 % mortality against nanoformulated chlorfenapyr (1.5 %). Nanoformulated clothianidin induced more than 92 % and ∼ 100 % mortality against An. funestus and An. coluzzii respectively. However, Cx. quinquefasciatus significantly showed less mortality against nanoformulated clothianidin (88 %) and chlorfenapyr (>95 %) as compared to Anopheline strains. Furthermore, results indicate that nanoformulated insecticides significantly caused greater and prolonged fatality as compared to conventional form, suggesting effective and suitable strategies for vector management.

Effect of abamectin and profenofos insecticide on stingless bee, Tetragonula laeviceps Smith (Hymenoptera: Apidae: Meliponini)

Pollinators such as the bee Tetragonula laeviceps Smith are essential components of ecosystems that provide services to plants. However, the massive use of pesticides in crops can affect the existence of pollinating bees and even cause a decrease in bee populations in the field. This study aimed to determine the effect of abamectin and profenofos insecticides on T. laeviceps. The methods used in the test were bee attractiveness bioassay, toxicity test of dermal application (topical and residual), and oral application with the abamectin and profenofos. The results of the bioassay showed that bees were more attracted to the aroma of the insecticide abamectin 180 ppm than profenofos 1500 ppm. The recommended concentrations of abamectin and profenofos in the field were 180 and 1500 ppm, respectively, so this topical and oral application showed a high level of danger to bees because it can kill >80% of bees. The LD50 values of the insecticides abamectin (0.0064 ppm) and profenofos (0.0345 ppm) were classified as highly toxic based on EPA classification. Therefore, insecticides with active ingredients, particularly abamectin and profenofos, are harmful to T. laeviceps.

Evaluation of the Efficacy of Several Plant-Based Insecticides and Aqueous Nano-Silica Formulations Against the Rust-Red Flour Tribolium castaneum (Herbst.) Under Laboratory Conditions

Laboratory studies were conducted to evaluate the effects of plant-based insecticides such as Tandexir and Balizin, hydrophilic nanosilica compounds in addition to biopesticides synergistic with nanocompounds to estimate the effects of rust-red flour beetle Tribolium castaneum the mortality percentage Efficacy was evaluated. The results showed the effectiveness of tundexir insecticide with a statistically significant difference of up to 75% in obtaining higher mortality rate, compared to Balizin which obtained a rate of 63.61%. Furthermore, the results showed that 4 ml liter-1 dose of Tandexir was more effective than Balizin with a statistical difference after 5 days of treatment, resulting in mortality rates of 93.33% and 83.33%, respectively. For both formulations, a dose of 4 ml litre-1 was the most effective in obtaining mortality, and 100% was recorded after 7 days of treatment The results of the efficacy study of the nanosilica formulations showed that the 0.4 g liter-1 dose showed high mortality at 100% after 7 days of treatment, when mortality time was obtained comparing dosages of 0.2 and 0.3 g liter-1 in at the same time 76 .66% and 83.33%. The results showed that using plant-based insecticides at a concentration of 2 ml per liter of water, together with 0.2 grams per liter of a water-friendly nanosilica compound, worked really well together. Tundexir exhibited superior performance in achieving higher mortality rates, reaching 100% after 7 days of treatment, with a mortality rate of 84.16%, compared to Balizin, which achieved a mortality rate of 96.66% at a concentration of 77.50%.

A perspective on the worst ever dengue outbreak 2023 in Bangladesh: What makes this old enemy so deadly, and how can we combat it?

AbstractBackground and AimsBangladesh has been going through outbreaks of dengue fever cases every year since 2000. Yet this year's (2023) episode of dengue fever has crossed every line concerning fatality. Symptoms of the fever range from high fever, headaches, and muscle aches to deadly dengue hemorrhagic fever (DHF). The present review aims to assess the current pathogenicity and associated risk factors of recent dengue outbreaks in Bangladesh.MethodsTo perform this review work, we extracted relevant information from published articles available in PubMed, Scopus, and Google Scholar. We used dengue virus, dengue fever, and dengue outbreaks as keywords while searching for information.ResultsThis Aedes mosquito‐transmitted viral fever is more common in Bangladesh because of the tropical nature and immense burden of populations, resulting in convenient conditions for the reproduction of the vector. The rapid genetic transformation of this RNA virus and the resistance of its vector against insecticides have intensified the situation. The number of hospitalized patients has increased, and the case fatality rate has risen to 0.47%. Inadequate mosquito control measures, plenty of vector breeding sites, and a lack of public awareness have worsened the situation. Routine spraying of effective insecticides in high‐risk zones, regular inspection of potential mosquito breeding sites, and public awareness campaigns are the keys to limiting the spread of this virus. Also, the availability of detection kits, improved hospital settings, and trained health professionals are mandatory to keep disease fatalities under control.ConclusionDengue fever is a preventable disease. The successful development of a competent vaccine is now a prime need for preventing any future upsurge of the disease. Also, we recommend public awareness, vector control activities, and global collaboration to prevent spread.

Combinational Toxic Effect of Insecticide and Fungicide on Hematological Indicators in Mice

Exposure to two or more compounds in a living system may result in unexpected outcomes. The present study was planned to investigate the effect of two pesticides, Imidacloprid (IMI) and Carbendazim (CBZ), when exposed alone and in combination, on hematological indicators. All mice were equally divided into six different groups consisting of normal control, IMI-L & IMI-H (45.5 & 90.0 mg/kg feed, respectively), CBZ-L & CBZ-H (1.4 and 2.8 g/kg feed, respectively) alone, and in combination (IMI-L+CBZ-L). Blood was collected, and hematology was performed upon completion of the 28-day feeding period. Results revealed that exposure to IMI and CBZ did not show apparent signs and symptoms of toxicity except for the IMI high dose alone. The net average feed and water consumption per mouse were comparatively less in the IMI-H and CBZ-H groups compared to the control group. A dose-dependent significant change (p<0.05) in TLC, TEC, PCV, and Hb values was noticed in treatment groups. Non-significant changes (p>0.05) in the percent lymphocyte, eosinophil, and monocyte were noticed between all the treatment groups. No significant change (p>0.05) in the values of Hb, PCV, MCV, and MCH of the IMI-L+CBZ+L treated group was noticed when compared with the respective IM-L and CBZ-L groups. A non-significant change (p>0.05) in studied parameters was noticed when compared between IMI-L+CBZ-L treated groups with corresponding CBZ-L and IMI-L alone treatment groups. Based on the interactive index, the study concluded that a combination of IMI and CBZ exposure via the dietary medium has no definitive additive or synergistic toxic effect on hematological indicators.

The impact of resource limitation on the pest-natural enemy ecosystem with anti-predator behavior and fear effect

Research on agricultural pest control data indicates that the actual effectiveness of insecticides may exhibit slight variations, influenced by factors such as the type and quantity of pests. Additionally, the development of resistance by pests, as a result of adaptation to the environment, can impact the precision of pest control strategies. Hence we suggest implementing a nonlinear pulse state-dependent feedback control system, considering resource limitations, to investigate the influence of varying pesticide fatality rates on pest outbreaks. This paper takes into account the fear effect and anti-predator behavior to accurately portray the farmland ecosystem. We assessed the phase set and Poincaré map under the conditions for the existence of order-k (where k=1,2,3\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$k=1,2,3$\\end{document}) periodic solutions and examined their stability behavior. Remarkably, the system exhibited diverse bifurcation phenomena associated with pesticide-related parameters. Furthermore, the system demonstrated a multistability phenomenon involving the coexistence of the order-1 periodic solution and the limit cycle. This suggests that altering control strategies can disturb the initial coexistence status of pests and natural enemies. It also underscores that resource limitations can indeed impact the outbreak patterns and frequencies of pests. In addition to the variability in pesticide fatality rates, the inclusion of natural enemy releases in the nonlinear pulse strategy contributes to the model exhibiting complex dynamic characteristics. All these findings are substantiated by numerical simulations.

Assessment of the efficacy of Piper methysticum (Micrembryeae: Piperaceae) as a bioinsecticide, and/or spinosad combined with attractive plant volatiles for a novel lure and kill strategy against Bactrocera tryoni (Diptera: Tephritidae) in laboratory.

The Queensland fruit fly, Bactrocera tryoni (Froggatt) (Diptera: Tephritidae), is a crop pest of global economic importance because of its wide range of hosts and its invasiveness capacities. To develop a novel integrated and sustainable crop protection, we have investigated the insecticidal properties of different varieties of kava (Piper methysticum [Frost]) extracted by two methods and the attractive effects of six plant volatiles identified from B. tryoni host plants to female, mated or not. We did not identify any significant insecticidal effect of the traditional Pacific kava plant at the tested concentrations. Among mated females, ethyl acetate compared to the no odor control elicited the highest attraction (87%, of which 60% for this odor), while ethyl butyrate was preferred compared with ethyl acetate in dual choice assays. Flies' preferences for specific odors depended on their mating status and the odor landscape they were confronted with. Combination with the commercial ingestion insecticide (Success 4: spinosad, 480 g/l, Dow AgroSciences, Valbonne, France) with the plant volatiles were tested to detect an increase in mortality related to the addition of an attractant. The 2-heptanone slightly showed a tend to increase the attractiveness of mated females within 4-6 h to the food bait, but the results were not statistically significant after 8 h. Further tests should be performed with other concentrations or mixtures of the identified host plant volatiles to develop a strong lure and kill strategy.

Genome-wide identification of G-protein coupled receptors (GPCRs) and their expression profile in response to β-cypermethrin stress in Zeugodacus cucurbitae

G-protein coupled receptors (GPCRs) are the largest and most diverse transmembrane receptor family in the cell. They are involved in regulating a wide range of biological processes, including behavior, reproduction, and development. However, GPCRs have not yet been identified in Zeugodacus cucurbitae. The current study focuses on the GPCRs identification, classification, distribution, and their expression analysis under β-cypermethrin stress to uncover novel targets for pest management and assist in the development of effective strategies for controlling the melon fly population. We identified 80 GPCRs genes including 50 GPCRs identified in family A, 17 GPCRs identified in family B, 8 identified in family C, and 5 identified in family F. Z. cucurbitae GPCRs showed significant differences in both the number of genes in families or subfamilies, as well as the sequencing of the genes. Interestingly, newly identified GPCRs genes are expressed differently at various developmental stages of Z. cucurbitae. Further, we evaluated these 80 GPCRs using Realtime quantitative PCR to confirm their expression between β-cypermethrin-resistant (RS) strain and susceptible strain (SS) of Z. cucurbitae. We identified 50 GPCR genes were highly overexpressed in a RS. Among these genes, eight genes were strongly induced by the 30% lethal concentration (LC) while two genes were significantly increased by the 50% LC of β-cypermethrin. This first genome-wide profiling and characterization of GPCRs could lay foundation for unraveling detoxification mechanism and target site modifications which may improve the insect resistance and could be effective insecticide targets for Z. cucurbitae management.

Evaluation of Fermented Plant Extracts as Bioinsecticides in Controlling Phenacoccus solenopsis Colonies on Hibiscus rosa-sinensis under Laboratory Conditions

The mealybug, Phenacoccus solenopsis, is a serious pest of Hibiscus rosa-sinensis. The waxy coating on its body may hinder pesticide penetration, and the extensive use of pesticides is risky to humans and the environment. Considering these drawbacks, fermented plant extracts (FPEs) were explored for their potential use in controlling this pest in a more user and environmentally-friendly manner. FPEs derived from eleven plant materials were evaluated against P. solenopsis for their insecticidal activity, mealybug wax removal potential and phytotoxicity effect on H. rosa-sinensis. Five concentrations of FPE [5, 10, 15, 20, and 25% (w/v)] were prepared. Among the 11 FPEs, FPE derived from ficus, kaffir lime, and turmeric were effective in suppressing P. solenopsis with lethal concentration at 50% (LC50 value) less than 20% concentration. Although ficus FPE was the top performer in the insecticidal assay, it induced medium to very high levels of leaf damage after being treated with 15–25% concentration at 24 and 72 hr post-treatment. A low level of leaf damage was observed in treatment with turmeric and kaffir lime FPEs at 72 hr post-treatment. FPEs could remove wax from the body of P. solenopsis with no significant difference among them. In conclusion, the FPE of ficus, kaffir lime, and turmeric showed promising insecticidal effects against P. solenopsis.

Transcriptome analyses in juvenile yellow perch (Perca flavescens) exposed in vivo to clothianidin and chlorantraniliprole: Possible sampling bias.

The St. Lawrence River is an important North American waterway that is subject to anthropogenic pressures including intensive urbanization, and agricultural development. Pesticides are widely used for agricultural activities in fields surrounding the yellow perch (Perca flavescens) habitat in Lake St. Pierre (Quebec, Canada), a fluvial lake of the river where the perch population has collapsed. Clothianidin and chlorantraniliprole were two of the most detected insecticides in surface waters near perch spawning areas. The objectives of the present study were to evaluate the transcriptional and biochemical effects of these two pesticides on juvenile yellow perch exposed for 28d to environmental doses of each compound alone and in a mixture under laboratory/aquaria conditions. Hepatic mRNA-sequencing revealed an effect of chlorantraniliprole alone (37 genes) and combined with clothianidin (251 genes), but no effects of clothianidin alone were observed in perch. Dysregulated genes were mostly related to circadian rhythms and to Ca2+ signaling, the latter effect has been previously associated with chlorantraniliprole mode of action in insects. Moreover, chronic exposure to clothianidin increased the activity of acetylcholinesterase in the brain of exposed fish, suggesting a potential non-target effect of this insecticide. Further analyses of three clock genes by qRT-PCR suggested that part of the observed effects of chlorantraniliprole on the circadian gene regulation of juvenile perch could be the result of time-of-day of sacrifice. These results provide insight into biological effects of insecticides in juvenile perch and highlight the importance of considering the circadian rhythm in experimental design and results analyses.

Toxicity of Cry- and Vip3Aa-Class Proteins and Their Interactions against Spodoptera frugiperda (Lepidoptera: Noctuidae).

The fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith), is one of the most important insect pests affecting corn crops worldwide. Although planting transgenic corn expressing Bacillus thuringiensis (Bt) toxins has been approved as being effective against FAW, its populations' resistance to Bt crops has emerged in different locations around the world. Therefore, it is important to understand the interaction between different Bt proteins, thereby delaying the development of resistance. In this study, we performed diet-overlay bioassays to evaluate the toxicity of Cry1Ab, Cry1Ac, Cry1B, Cry1Ca, Cry1F, Cry2Aa, Cry2Ab, Vip3Aa11, Vip3Aa19, and Vip3Aa20, as well as the interaction between Cry1Ab-, Cry1F-, Cry2Ab-, and Vip3Aa-class proteins against FAW. According to our results, the LC50 values of Bt proteins varied from 12.62 ng/cm2 to >9000 ng/cm2 (protein/diet), among which the Vip3Aa class had the best insecticidal effect. The combination of Cry1Ab and Vip3Aa11 exhibited additive effects at a 5:1 ratio. Cry1F and Vip3Aa11 combinations exhibited additive effects at 1:1, 1:2, and 5:1 ratios. The combination of Cry1F and Vip3Aa19 showed an antagonistic effect when the ratio was 1:1 and an additive effect when the ratio was 1:2, 2:1, 1:5, and 5:1. Additionally, the combinations of Cry1F and Vip3Aa20 showed antagonistic effects at 1:2 and 5:1 ratios and additive effects at 1:1 and 2:1 ratios. In addition to the above combinations, which had additive or antagonistic effects, other combinations exhibited synergistic effects, with variations in synergistic factors (SFs). These results can be applied to the establishment of new pyramided transgenic crops with suitable candidates, providing a basis for FAW control and resistance management strategies.

A novel albumin-based supramolecular biosensor for ratiometric on-site determination of buprofezin

Buprofezin (BUP) is an effective insecticide against Homopteran and Thysanoptera pests. However, exposure to BUP may result in several harmful effects on the non-target organism including human body, such as hepatotoxicity and DNA damage. Therefore, development of a reliable analytical method for BUP holds paramount importance. This study presents a novel albumin-based supramolecular biosensor, DPP@ALB, designed for the sensitive detection of BUP in environmental matrices, including water, soil, and real food samples. The features of this biosensor include a fast response, high sensitivity, and visually detectable fluorescence color change, enabling on-site detection of BUP based on the portable paper strips and 3D-printed miniaturized testing system. Overcoming challenges associated with the low chemical reactivity of BUP, this supramolecular biosensor emerges as the very first fluorescent sensor for efficient and reliable monitoring of BUP with applications in broader areas of environmental analysis and food safety.

Antenna-Biased Odorant Receptor PstrOR17 Mediates Attraction of Phyllotreta striolata to (S)-Cis-Verbenol and (-)-Verbenone.

Phyllotreta striolata, the striped flea beetle, is one of the most destructive pests in Brassicaceae plants worldwide. Given the drawbacks associated with long-term use of chemical insecticides, green strategies based on chemical ecology are an effective alternative for beetle control. However, the lack of information on beetle ecology has hindered the development of effective biocontrol strategies. In this report, we identified two odorants, (S)-cis-verbenol and (-)-verbenone, which displayed significant attraction for P. striolata (p < 0.05), indicating their great potential for P. striolata management. Using the Drosophila "empty neuron" system, an antenna-biased odorant receptor, PstrOR17, was identified as responsible for the detection of (-)-verbenone and (S)-cis-verbenol. Furthermore, the interactions between PstrOR17 and (-)-verbenone or (S)-cis-verbenol were predicted via modeling and molecular docking. Finally, we used RNAi to confirm that PstrOR17 is essential for the detection of (-)-verbenone and (S)-cis-verbenol to elicit an attraction effect. Our results not only lay a foundation for the development of new and effective nonchemical insecticide strategies based on (S)-cis-verbenol and (-)-verbenone, but also provide new insight into the molecular basis of odorant recognition in P. striolata.

Enhance the physicochemical properties of the citronella oil -SLNPs to improve the insecticidal activity against Spodoptera littoralis (Boisd) (Lep. Nactuidae)

The Nano-formulation of citronella essential oil (Cymbopogon nardus (L.) and their mixtures of three adjuvants (Provecta®, Top film®, and PEG600-dioleate) were studied to enhance physico-chemical properties of the Nano-formulation and improve the insecticidal effect against Spodoptera littoralis (Boisd). Characterisation of physicochemical properties of Nano-formulation was studied by calculating droplet size, polydispersity index (PDI), and Zeta-potential parameters. The results showed that the Solid Lipid Nanoparticles (SLNs) mixtures of three adjuvant mixtures had more toxic activity and stability than the Nano-formulation alone. Before storage the acidity, alkalinity (pH), and viscosity exhibited an acidic pH value in the range (4.11–5.34), whereas after three months of storage was recorded high pH, a shift in the pH on storage can indicate the instability of active substances or product under semi field-laboratory conditions. Nano-formulation of the citronella oil mixed with the three adjuvants increased the mortality percentage of S. littoralis larvae.

Efficacy of some botanical insecticides against &lt;em&gt;Aphis gossypii&lt;/em&gt; Glover (Hemiptera: Aphididae) on chrysanthemum

An evaluation of various botanical insecticides to control Aphis gossypii and its impact on aphid population dynamics on chrysanthemum plants was investigated. In order to control A. gossypii on chrysanthemum, the effectiveness of several botanical insecticides extracted from Melia azedarach, Toona sinensis, and Chrysanthemum cinerariaefolium was investigated in the current study. The research was carried out in the experimental field of the Indonesian Ornamental Crops Research Institute under plastic house conditions. Five concentrations, i.e., 1.5, 2.0, 2.5, 3.0, and 3.5 g/L of three plant extracts, M. azedarach, T. sinensis, and C. cinerariaefolium, were sprayed on chrysanthemum cultivar White Fiji after 28 to 84 days after planting. A. gossypii had a dynamic population that changed according to the plant’s developmental stages. In vegetative growth, the alate adult and nymphal stages were dominant, and the population of nymphs increased along the plant ages. The insect colonized young leaf surfaces in the terminal apices. During the reproductive stages, the population of alate adults diminished, and the distribution of the insect extended to mature, old leaves, flower buds, and bloomed flowers. The application of several botanical insecticides revealed various responses of aphid populations. Among the tested insecticides, C. cinerariaefolium extract at 3.0 and 3.5 g/L demonstrated the highest average percentage efficacy (76 and 72%) and was the most consistent in suppressing the population. The results of this study indicate the potential efficacy of botanical insecticides against A. gossypii suggesting a different approach to efficient and environment-friendly chrysanthemum pest management.