Antifeedant Effects Research Articles

Control of Diaphorina citri (Hemiptera: Liviidae) using environmentally friendly chemical alternatives

Diaphorina citri poses a serious threat to citrus. Here, the nymphicidal activity of mineral and soybean oils, organosilicon, and citrus-essential-oil-derived adjuvants was evaluated. Additionally, mineral and soybean oils were studied for antifeedant and repellent effects on adults. Residual effect on the parasitoid Tamarixia radiata was also assessed. Nymphicidal activity ranged between 65–83%, with Silwet enhancing mineral and soybean oil efficacy. Evaluated soybean and mineral oil exhibited comparable antifeedant and repellent effects on adults. All products caused <20% mortality in T. radiata, even 24 h after spraying. Overall, tested adjuvants and oils offer promising eco-friendly alternatives for sustainable D. citri management.

Applications of Plant Essential Oils in Pest Control and Their Encapsulation for Controlled Release: A Review

Essential oils (EOs) are volatile products derived from the secondary metabolism of plants with antioxidant, antimicrobial, and pesticidal properties. They have traditionally been used in medicine, cosmetics, and food additives. In agriculture, EOs stand out as natural alternatives for pest control, as they show biocidal, repellent, and antifeedant effects. However, they are highly volatile compounds and susceptible to oxidation, which has limited their use as pesticides. This has led to exploring micro- and nano-scale encapsulation to protect these compounds, improving their stability and allowing for a controlled release. Various encapsulation techniques exist, such as emulsification, ionic gelation, and complex coacervation. Nanoemulsions are useful in the food industry, while ionic gelation and complex coacervation offer high encapsulation efficiency. Materials such as chitosan, gelatin-gum-Arabic, and cyclodextrins are promising for agricultural applications, providing stability and the controlled release of EOs. Encapsulation technology is still under development but offers sustainable alternatives to conventional agrochemicals. This article reviews the potential of EOs in pest management and encapsulation techniques that enhance their efficacy.

Nematicidal and Insecticidal Compounds from the Laurel Forest Endophytic Fungus Phyllosticta sp.

The search for natural product-based biopesticides from endophytic fungi is an effective tool to find new solutions. In this study, we studied a pre-selected fungal endophyte, isolate YCC4, from the paleoendemism Persea indica, along with compounds present in the extract and the identification of the insect antifeedant and nematicidal ones. The endophyte YCC4 was identified as Phyllosticta sp. by molecular analysis. The insect antifeedant activity was tested by choice bioassays against Spodoptera littoralis, Myzus persicae, and Rhopalosiphum padi, and the in vitro and in vivo mortality was tested against the root-knot nematode Meloidogyne javanica. Since the extract was an effective insect antifeedant, a strong nematicidal, and lacked phytotoxicity on tomato plants, a comprehensive chemical study was carried out. Two new metabolites, metguignardic acid (4) and (-)-epi-guignardone I (14), were identified along the known dioxolanones guignardic acid (1), ethyl guignardate (3), guignardianones A (5), C (2), D (7), and E (6), phenguignardic acid methyl ester (8), the meroterpenes guignardone A (9) and B (10), guignarenone B (11) and C (12), (-)-guignardone I (13), and phyllomeroterpenoid B (15). Among these compounds, 1 and 4 were effective antifeedants against S. littoralis and M. persicae, while 2 was only active on the aphid M. persicae. The nematicidal compounds were 4, 7, and 8. This is the first report on the insect antifeedant or nematicidal effects of these dioxolanone-type compounds. Since the insect antifeedant and nematicidal activity of the Phyllosticta sp. extract depend on the presence of dioxolanone components, future fermentation optimizations are needed to promote the biosynthesis of these compounds instead of meroterpenes.

Novel Pesticide Candidates Inspired by Natural Neolignan: Preparation and Insecticidal Investigation of Honokiol Analogs Containing 2-Aminobenzoxazole-Fused Core Scaffold.

As a continuation of our efforts to develop new agrochemicals with typical architecture and efficient bioactivity from plant natural products, natural neolignan honokiol was used as a lead compound to prepare novel analogs bearing the core 2-aminobenzoxazole scaffold. Their insecticidal potency against two representative agricultural pests, Plutella xylostella Linnaeus and Mythimna separata (Walker), were evaluated in vivo. The pesticide bioassay results revealed that compounds 7″a, 9, 10d, and 10j exhibited prominent larvicidal activity against the larvae of P. xylostella (LC50 = 7.95, 11.85, 15.51, and 12.06 μg/mL, respectively), superior to the precursor honokiol (LC50 = 43.35 μg/mL) and two botanical insecticides, toosendanin (LC50 = 26.20 μg/mL) and rotenone (LC50 = 23.65 μg/mL). Compounds 7d, 10d, and 10j displayed a more pronounced nonchoice antifeedant effect (AFC50 = 9.48, 9.14, and 12.41 μg/mL, respectively) than honokiol (AFC50 = 54.81 μg/mL) on P. xylostella. Moreover, compounds 7b, 7″a, 9, 10d, 10f, and 10j showed better growth inhibitory activity against M. separata (LC50 = 0.36, 0.34, 0.28, 0.16, 0.26, and 0.11 mg/mL, respectively) than honokiol, toosendanin, and rotenone (LC50 = 1.48, 0.53, and 0.46 mg/mL, respectively). A potted plant assay under greenhouse conditions illustrated that compounds 10d and 10j continued to provide good control efficacy against P. xylostella and an apparent protective effect on plants. Further cytotoxicity assay revealed that the aforementioned potent compounds showed relatively moderate toxicity and a good safety profile for non-target mammalian cells. Overall, the current work provides valuable insight into the agrochemical innovation of honokiol-derived analogs for use as natural-inspired pesticides in agricultural pest management.

Design, Synthesis, and Antifeedant Activity Evaluation of 13/14-Arylthioether Matrine Derivatives.

Introducing a sulfur atom into active agricultural molecules is an important strategy for pesticide development. Matrine, an environmentally friendly botanical pesticide, has the advantage of being easily degraded and has drawn attention in the agricultural field. To explore the novel matrine-type pesticides, in this study, we designed and synthesized 13/14-arylthioether matrine derivatives by introducing various aryl sulfide motifs into bioactive matrine. Most of the synthesized arylthioether matrines exhibited good antifeedant activity against Spodoptera exigua. Among them, compound 2q showed the best antifeedant effect with an EC50 value of 0.038 mg/mL, which is approximately 125-fold more activity than matrine and reached the activity level of commercial standard azadirachtin A. Furthermore, compound 2q exhibited an inhibitory effect on antifeedant-related enzyme carboxylesterase (CarE) from S. exigua. In short, the high activity of arylthioether matrines offers new insights into developing new antifeedants.

Antifeedant and growth inhibitory effects of extracts from Ajania potaninii and A. fruticulosa against Tribolium castaneum (Coleoptera: Tenebrionidae)

This study aimed to evaluate the nutritional and antifeedant indices of Tribolium castaneum in response to the compounds and main chemical constituents ofAjania potaninii and A. fruticulosa. These mainly includes essential oils and their major ingredients (eucalyptol, camphor, myrtenol, verbenol, and borneol), as well as nonvolatile compounds. The A. fruticulosa and A. potaninii EOs exhibited clear antifeedant activity against T. castaneum adults at a 2 mg/L concentration, with FDI of 50% and 60%, respectively. Among the nonvolatile compounds, sesamin and eriodictyol exhibit strong antifeedant activities against T. castaneum adults at the same concentration, with an FDI of 90.57% and 88.68% after 72 h, respectively. For larvae, A. fruticulosa and A. potaninii EOs also resulted in antifeedant activity (respective FDI: 57.08% and 55.63%). In addition, sesamin and eriodictyol had exceptionally potent antifeedant activity against T. castaneum larvae, with FDI values 90.71% and 96.17%, respectively. In nutritional studies, the reductions in relative food consumption rate (RCR) of T. castaneum were more pronounced for 1 mg/L and 2 mg/L of either eucalyptol or sesamin. However, at greater concentrations, the conversion efficiency of eucalyptol and sesamin to ingested food in T. castaneum was significantly improved. Eucalyptol and sesamin showed a dose-dependent FDI for this insect. Considering the significant anti-insect activities, the EOs, main compounds, and non-volatile compounds of both A. potaninii and A. fruticulosa might be useful in devising integrated pest strategies, providing a promising perspective for the comprehensive use of natural plant resources from the Ajania genus.

Induction of antiherbivore defense responses in poplars using a methyl jasmonate and mesoporous silica nanoparticle complex.

Poplar in China has long been plagued by the fall webworm Hyphantria cunea. Enhancing plant immunity using chemical elicitors is an environmentally friendly approach to pest control. The phytohormone methyl jasmonate (MeJA) can stimulate the chemical defenses of poplars against herbivores but has been shown to have limited efficacy in practice. Here, we studied the effects of a MeJA and mesoporous silica nanoparticle (MSN) complex (MeJA@MSN) regarding the induction of poplar resistance to H. cunea, which may provide strategies for the effective use of MeJA. The silicon-based phytohormone complex (MeJA@MSNs) exhibited excellent biological and physiochemical properties, such as excellent biocompatibility and plant tissue transportability. The changes in metabolites in poplar leaves induced by MeJA, MSNs, and MeJA@MSNs were investigated by metabolic analysis. MeJA@MSNs led to highly potent induced resistance along with elevated salicylaldehyde content, which increased with the dose administered. The salicylaldehyde metabolite showed a strong antifeedant effect on H. cunea larvae at a dosage of 1 μg, with the 50% lethal dose being 20.4 μg/mg. Furthermore, transcriptional analysis showed that MeJA@MSNs upregulated key genes in biosynthetic pathways more than MeJA and MSNs. Our results show that MeJA and MSNs interact positively in poplar, leading to salicylaldehyde accumulation and increased induced resistance to H. cunea, providing new insights into the underlying resistance mechanisms induced by MeJA@MSNs. © 2024 Society of Chemical Industry.

Bio-efficacy of Solanum torvum (Sw.) against agricultural pest Spodoptera litura (Fab.) (Lepidoptera: Noctuidae)

Recently, Spodoptera litura (Fab.) has emerged as a significant threat to the environment. Because of the pest's ability to spread, pesticides are often applied to agricultural crops. By combining certain plant extracts with other compounds, both a reduction in insect infestation and an increase in production could be achieved. The antifeedant, larvicidal and histological effects of Solanum torvum (Sw.) leaf extracts were investigated against S. litura. The study found that the ethyl acetate leaf extract showed a significant antifeedant effect against S. litura of (86.16%) at 5% concentration. Ethyl acetate extract showed larvicidal activity against S. litura of 88.21% and the LC50 value was 2.05%. Exposure of larvae to ethyl acetate leaf extract resulted in significant histological damage, particularly affecting epithelial, goblet and digestive cells. The results suggest that the inclusion of these plant extracts in integrated pest management approaches can promote sustainable and environmentally friendly pest control methods in agriculture.

Actinobacteria mediated synthesis of silver nanoparticles using Streptomyces diastaticus and their biological efficacy against human vector mosquitoes and agricultural insect pests

Mosquitoes and agricultural insects were harmful to both public health and crops. Prolonged use of synthetic chemical pesticides for insect pest control was associated with resistance development and negative human and ecological effects. This study investigates the larvicidal activity of Ag-NPs produced using Streptomyces diastaticus against Culex quinquefasciatus, Anopheles stephensi, Aedes aegypti, Spodoptera litura, and Plutella xylostella. UV-Vis spectroscopy, XRD, SEM-EDX, FT-IR, TEM, DLS, and Zeta potential analysis were used to characterize the biosynthesized Ag-NPs. The results showed that biosynthesized Ag-NPs were more toxic to, A. stephensi, C. quinquefasciatus, and A. aegypti with LC50 values of 15.70, 11.10, and 17.53 µg/mL, respectively. Biosynthesized Ag-NPs exhibited the highest antifeedant effects against S. litura (88.73 %) and P. xylostella (92.36 %) at 50 µg/mL concentration. The mortality bioassay revealed considerable larvicidal activity against S. litura and P. xylostella larvae at greater doses of 50 µg/mL, 80.67 and 84.05 %, respectively. Morphogenetic variations were observed on treated larvae of C. quinquefasciatus, A. aegypti, and A. stephensi, S. litura, and P. xylostella with Ag-NPs. In the present investigation the impact of Ag-NPs on the antioxidant enzymes (SOD, CAT, and GPx), the activity of each enzyme were dramatically increased with higher concentrations resulting in significant differences. The study also found that Ag-NPs inhibited the detoxifying enzyme (GST and AChE) activity of target organisms. The histological structure of the treated and untreated larvae revealed structural changes between the midgut epithelial cells. As a consequence of these findings, the S. diastaticus-mediated Ag-NPs serve as a possible, eco-friendly biopesticide and alternative to synthetic chemicals for the control of human vector mosquitoes and destructive arthropod insect pests.

Feeding Performance of Argentine Stem Weevil Is Reduced by Peramine from Perennial Ryegrass Infected with Endophyte Fungus.

One of the primary supports for extensive agriculture is pasture, which can suffer severe damage from insects including the Argentine stem weevil, Listronotus bonariensis. The main control method has been the infection of ryegrass with an endophyte fungus, forming a symbiotic association that produces alkaloids. In this study, we evaluated the impact of endophyte and peramine production on the weight of L. bonariensis across seven unnamed lines (LE161-LE167), and two Lolium perenne cultivars: Jumbo and Alto AR1. L. bonariensis adults fed on leaves from LE164, LE166, and ALTO AR1 showed weight losses of 13.3%, 17.1% and 18.2%, respectively. Similarly, the corresponding alkaloidal extract from LE164, LE166, and ALTO AR1 exhibited an antifeedant effect on L. bonariensis adults in laboratory assays, as observed through weight loss or low weight gain (-12.5%, 8.8% and 4.9%, respectively). Furthermore, one alkaloid, peramine, also elicited an antifeedant effect when incorporated into an artificial diet. Liquid chromatographic analysis of the alkaloid extract revealed that peramine was present in LE164, LE166 and ALTO AR1 in amounts ranging from 46.5-184.2 ng/g. Peramine was not detected in Jumbo and the remaining experimental lines. These data suggest that L. bonariensis were susceptible to peramine produced from endophyte infection in experimental lines LE164 and LE166, as well as ALTO AR1, affecting their feeding behavior.

Insecticidal, antifeedant, and repellent effect of Lavandula mairei var. antiatlantica essential oil and its major component carvacrol against Sitophilusoryzae

The genus Lavandula encompasses plants commonly known for their bioactivities and applications as insecticides. Despite this recognition, certain species such as Lavandula mairei Humbert have received no attention. For this reason, our study offers a close insight into the chemical profile, insecticidal (i.e. fumigant and contact toxicity), repellent, and antifeedant effect of Lavandula mairei var. antiatlantica (Maire) Maire essential oil (LMEO) against Sitophilus oryzae (L.), a major stored product insect. Additionally, the major compound of LMEO, i.e. carvacrol, was also tested for the aforementioned bioactivities. In the fumigant bioassays LMEO and carvacrol showed LC50 values of 69.5 and 69.3 μL/L of air, respectively, after 72 h while in the contact bioassays LC50 values of 0.14 and 0.117 μL/insect, respectively, after 24 h. In terms of antifeedant effect, carvacrol and LMEO significantly influenced the Feeding Deterrent Index (FDI) recording 83.2 and 55.0%, respectively, at a concentration of 3.2%. Furthermore, a notable reduction of 5.5 and 2.1-fold in Relative Consumption Rate (RCR) was observed for carvacrol and LMEO, respectively, compared to the control. Regarding the repellent effect, carvacrol and LMEO exhibited percentages of repellency (PR) of 94 and 82%, respectively, at 0.312 μL/cm2 after 24 h. In conclusion, our study underscores the significant insecticidal, feeding deterrent, and repellent effects of LMEO and its major compound against the rice weevil. Its cultivable potential and bioactivities confirmed through this study promote its use as sustainable pest control solution.

Bioassay-Guided and DeepSAT-Driven Precise Mining of Monoterpenoid Coumarin Derivatives with Antifeedant Effects from the Leaves of Ailanthus altissima.

Demand for the exploration of botanical pesticides continues to increase due to the detrimental effects of synthetic chemicals on human health and the environment and the development of resistance by pests. Under the guidance of a bioactivity-guided approach and HSQC-based DeepSAT, 16 coumarin derivatives were discovered from the leaves of Ailanthus altissima (Mill.) Swingle, including seven undescribed monoterpenoid coumarins, three undescribed monoterpenoid phenylpropanoids, and two new coumarin derivatives. The structure and configurations of these compounds were established and validated via extensive spectroscopic analysis, acetonide analysis, and quantum chemical calculations. Biologically, 5 exhibited significant antifeedant activity toward the Plutella xylostella. Moreover, tyrosinase being closely related to the growth and development of larva, the inhibitory potentials of 5 against tyrosinase was evaluated in vitro and in silico. The bioactivity evaluation results highlight the prospect of 5 as a novel category of botanical insecticide.

Evaluating the Antifeedant Effects of Andrographolide-based Formulations against Lampides boeticus L., under Laboratory Condition

Aims: To evaluate the antifeedant activity of Lampides boeticus (Linnaeus,1767), larvae exposed to various concentrations of Andrographolide-based formulations under laboratory conditions.&#x0D; Study Design: Completely Randomized Design&#x0D; Place and Duration of Study: Department of Entomology, College of Agriculture, Vellayani and NCESS, Kerala during 2019- 2023.&#x0D; Methodology: The experiment was conducted with 9 treatments and 4 replications, treatments included various concentrations (1,3,5 and 7%) of formulations A (Andrographolide (70%) + Neem oil (20%) + Triton X-100 (10%)) and B (Andrographolide (70%) + Pungam oil (20%) + Triton X-100 (10%)). To assess the impact of formulations in the feeding behaviour of freshly moulted third instar larvae of L.boeticus L., no choice bioassay method was used. Each Petri plate lined with moist filter paper, confined a single larva with the treated pods of each specific concentration. The weight of the food consumed by the larvae was recorded at an interval of 24 hours after treatment and calculated percent feeding, per cent feeding inhibition, antifeedant activity (protection over control) and preference index of L. boeticus L., larvae against the formulations.&#x0D; Results: The results revealed that 7% of formulation A exhibits the highest larval feeding inhibition (93.05%), followed by 7% of formulation B (87.81%). Both formulations at 5% concentrations also demonstrate significant antifeedant effects. Preference index values categorize 7% of formulations A and B as extremely antifeedant. The findings highlight the efficacy of these formulations in inhibiting larval feeding, with potential applications in pest management strategies.&#x0D; Conclusion: The present findings have demonstrated the notable efficacy of formulations A and B, particularly at the 7% concentration, in significantly inhibiting larval feeding of L.boeticus L., and the reduction in larval feeding percentages, coupled with high antifeedant activity and feeding inhibition rates, highlights the potential of andrographolide based formulations as potent biopesticides.

Exposure to insecticides cause mortality, respiratory disturbs, and antifeeding effects in Anticarsia gemmatalis

Exposure to insecticides cause mortality, respiratory disturbs, and antifeeding effects in Anticarsia gemmatalis

Toxicity Bioassays of Essential Oils against Hadda Beetle &lt;i&gt;Henosepilachna vigintioctopunctata&lt;/i&gt; (F)

Contact, repellent and antifeedant bioassays of essential oils (EO’s) viz., basil oil and citronella oil were evaluated against hadda beetle Henosepilachna vigintioctopunctata (F) in brinjal. Based on the results of leaf dip bioassay, the LC50 and LC90 values of basil oil and citronella oil were 1.25% and 2.85%, 0.93% and 1.52%, respectively at 24 hrs after treatment (HAT). While the corresponding LC50 and LC90 values at 48 HAT were 0.85% and 1.70%, 0.63% and 1.14%, respectively. Repellent and antifeedant effect of the chosen essential oils were also evaluated by modified preference method and no choice method, respectively. At 0.5 to 1% concentration, both basil and citronella oil showed 90-100% repellence at 30 and 60 min of treatment. 100% antifeedant effect was also observed at the same concentration (0.5 to 1%) for both the EO’s at 24 HAT. GC-FID/GC-MS analysis of basil and citronella oil revealed that the predominant component of basil oil was methyl chavicol (75.73%), followed by linalool (18.21%) and cuprenene (1.58%); in citronella oil, geranial (64.77%) was the most predominant component followed by citronellyl acetate (7.92%), geraniol (7.08%), (Z) iso citral (5.29%) and neral (3.60%).

The use of Phasmarhabditis nematodes and metabolites of Xenorhabdus bacteria in slug control.

Many species of slugs are considered serious pests in agriculture and horticulture around the world. In Europe, slugs of the genera Arion and Deroceras are the most harmful pests in agriculture. Therefore, the main goal of this study was to evaluate the effect of the whole-cell metabolites of 10 strains of five Xenorhabdus and three slug-parasitic nematodes (Phasmarhabditis hermaphrodita, Phasmarhabditis bohemica, and Phasmarhabditis apuliae) on the feeding behaviour and repellent effect on target slugs and evaluate a new possible means of biocontrol of these pests. The repellent and anti-feedant effects of nematode-killed insects, metabolites, slug-parasitic nematodes and a combination of metabolites and nematodes were studied through experimental designs: sand-filled plastic boxes divided into two parts in several modifications: with dead Galleria mellonella killed by nematodes, lettuce treated with bacterial metabolites and lettuce placed on the treated sand. We found that slugs avoid eating G. mellonella killed by nematodes, while they eat freeze-killed G. mellonella. Similarly, they avoid the consumption of lettuce in areas treated with bacterial metabolites (the most effective strains being Xenorhabus bovienii NFUST, Xenorhabdus kozodoii SLOV and JEGOR) with zero feeding in the treated side. All three Phasmarhabditis species also provided a significant anti-feedant/repellent effect. Our study is the first to show the repellent and anti-feedant effects of metabolites of Xenorhabdus bacteria against Arion vulgaris, and the results suggest that these substances have great potential for biocontrol. Our study is also the first to demonstrate the repellent effect of P. apuliae and P. bohemica. KEY POINTS: • Slugs avoid eating G. mellonella killed by entomopathogenic nematodes. • Bacterial metabolites have a strong repellent and antifeedant effect on slugs. • Presence of slug parasitic nematodes increases the repellent effect of metabolites.

Acetogeninas de Anonáceas: uma análise comparativa de sua atividade inseticida

Abstract: The Annonaceae family besides its commercial value ( Annona cherimola, , A. macroprophyllata, A. muricata, A. reticulata, A. purpurea , A. squamosa, Annona x atemoya) also produces several active secondary metabolites. Among these metabolites, Annonaceous acetogenins which are exclusive in this family, are reported with insecticidal activity on various species of insects that are crop pests and disease vectors. This review systematizes what is reported in the scientific literature about them: aspects such as the plant species from which the acetogenins come, and the insecticidal potential using the comparative activity index; it also takes into account lethality, morphological, physiological, and behavioral changes, including deterrent and anti-feeding effects. Eighty-five annonaceous acetogenins are documented on thirty species of insects, as well as toxic activities at various stages of development, broad-spectrum, and differential. The studies on Aedes aegypti (Diptera) and Spodoptera frugiperda (Lepidoptera) and the activity of squamocin on fifteen species of insects stand out. Annonaceous acetogenins are toxic at low concentrations, considering evaluation standards and comparison with commercial insecticides, and are active at various stages of insect development. The low proportion of studied species of the Annonaceae means the opportunity to find molecules with this biological potential, and an argument for its conservation.

Active defense strategies for invasive plants may alter the distribution pattern of pests in the invaded area.

In the invaded areas, it is believed that invasive species reduce their investment in defense due to the absence of natural enemies. By field investigation and a series of laboratory assays, This study explored the defense strategies of invasive plants. Field investigation indicated that invasive plants have a antifeedant effect on herbivorous pests, and the distribution frequency of wormholes of native plants shows a peak at a distance of 2-3 m from the invasive species. The feeding preference experiment conducted with two generalist herbivorous insects (native insect Spodoptera litura and invasive insect Spodoptera frugiperda) showed that the invasive plants have a stronger antifeedant effect than native plants. By analyzing the content of secondary metabolites in the leaves of three invasive plants (Sphagneticola trilobata, Mikania micrantha, Ipomoea cairica) and three native plants (Ipomoea nil, Paederia foetida, Polygonum chinense), the leaves of invasive plants had higher concentrations of substances associated with defenses, including total phenols, flavonoids, jasmonic acid, tannin, H2O2, and total antioxidant capacity (TAC), and lower soluble protein concentrations than native plants. After leaf damage, compared to native plants, the leaves of invasive plants showed an overall increase in substances associated with defense, except for soluble sugar. These results suggest that invasive plants maintain active defense strategies in invaded areas, leading to changes in the distribution patterns of herbivorous insects in a manner that facilitates invasion.

Effectiveness of Chicken Manure Flower Extract (Tagetes ercta L.) Against Mortality and Antifeedant in Chili Aphid Pests Myzus persicae sulz

This research was motivated by the chicken dung flower plant (Tagetes erecta L.) which is one of the plants that is often found in several areas in North Sulawesi, containing active chemical compounds such as alkaloids, terpenoids, saponins, tannins and flavonoids which can improve health. improve health. improve health. improve health. improve health. improve health. used as a vegetable protector. This study aims to determine the effectiveness of chicken manure flower extract on the mortality and antifeedant effect of chili aphids Myzus persicae sulz. This examination utilized an exploratory technique utilizing the leaf separate strategy utilizing a Totally Randomized Plan (CRD) design comprising of 4 treatments and 4 replications. Each treatment was given chicken manure flower extract with respective concentrations, namely P0 (0%), P1 (5%), P2 (10%), and P3 (15%). The results showed that the administration of chicken manure flower extract had a significant effect on the death of the chili aphid Myzus persicae sulz. The higher the extract from chicken manure flowers the higher the death rate of chili aphids Myzus persicae sulz and chicken manure flowers have an antifeedant effect at a concentration of 15%. So it can be concluded that giving chicken manure flower extract is effective in increasing the mortality of Myzus persicae sulz at a concentration of 15%, namely an average of 4.75 birds and has an antifeedant effect at a concentration of 15.%, namely an average of 0.350 grams.

The efficacy of Acorus calamus L. crude extract formulated in bentonite nanoparticles against Crocidolomia pavonana (Lepidoptera:Pyralidae)

The prospect of A. calamus extract to be botanical insecticides to control the insect pests is very promising. The insect control properties of the A. calamus are predominantly to have β-asarone, saponin and flavonoid. However, there are some factors limiting their efficacy. Short release rate at the point contact, the inherent volatility and vulnerability to oxidation and ultra-violet light are causing phytochemical changes during the application. Thus developing nanotechnology to increase their efficacy studied in this research. To develop the plant extract in nanoformulation, experiment on adsorption and desoption capacity were carried out with Acorus extract treated bentonite substrate analysed by GC techniques. In addition, to investigate the effectiveness of the plant extract treated bentonite were evaluated on Crocidolomia pavonana. Third instar larvae were used in the evaluation of antifeedant effect by using no choice methods. The results showed that Bentonite nanoparticles was effective in controlling the release of a bioactive element. Purifed clay bentonite for getting Na-bentonite increased the specific surface area of material therefore increased the adsorption site on the clay layer of the material. Crude extract of A.calamus can dissolve well in combination of water and organic solvents. Desorption experiments proved that Na-bentonite released more slowly than raw clay bentonite. Purification of bentonite to Na-bentonite resulted the changing of phytochemical properties bentonite which lead to an increase in the adsorption capacity of bentonite. In term of antifeedant evaluation based on damage to cabbage leaves seedling, the least damage was observed on leaves with nanoparticle plant extract formulation. The antifeedant index of A. calamus in nanoparticles formulation showed 25% higher that untreated cabbage plant seedling. The glasshouse trial was conducted to evaluate their efficacy on cabbage seedling. However, the brown leaves or phytotoxic effect has been found by the time the extracts nano formulation has been sprayed.