Significant Antifeedant Effect Research Articles

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.
 Study Design: Completely Randomized Design
 Place and Duration of Study: Department of Entomology, College of Agriculture, Vellayani and NCESS, Kerala during 2019- 2023.
 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.
 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.
 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.

Antifeedant and Antifungal Activities of Metabolites Isolated from the Coculture of Endophytic Fungus Aspergillus tubingensis S1120 with Red Ginseng.

A new globoscinic acid derivative, aspertubin A (1) along with four known compounds, were obtained from the co-culture of Aspergillus tubingensis S1120 with red ginseng. The chemical structures of compounds were characterized by using spectroscopic methods, the calculated and experimental electronic circular dichroism. Panaxytriol (2) from red ginseng, and asperic acid (4) showed significant antifeedant effect with the antifeedant rates of 75 % and 80 % at the concentrations of 50 μg/cm2 . Monomeric carviolin (3) and asperazine (5) displayed weak attractant activity on silkworm. All compounds were assayed for antifungal activities against phytopathogens A. tubingensis, Nigrospora oryzae and Phoma herbarum and the results indicated that autotoxic aspertubin A (1) and panaxytriol (2) possessed selective inhibition against A. tubingensis with MIC values at 8 μg/mL. The co-culture extract showed higher antifeedant and antifungal activities against P. herbarum than those of monoculture of A. tubingensis in ordinary medium. So the medicinal plant and endophyte showed synergistic effect on the plant disease resistance by active compounds from the coculture of A. tubingensis S1120 and red ginseng.

Selective Extraction of Bioactive Phenylethanoids from Digitalis obscura.

Cardenolide-free extracts from Digitalis obscura showed significant antifeedant effects against the aphid Myzus persicae and this activity correlated with their phenylethanoid content. The content in phenylethanoids of Digitalis obscura has been studied. Maceration of the aerial parts of D. obscura was used for the selective extraction of the natural compound rengyolone (1) and the aglycone of cornoside (compound 3). Pure rengyolone (1) can be obtained from D. obscura in approximately 90% purity from fresh plant from the CHCl3 soluble fraction of the ethanolic extract (0.8% yield). The ethanol extraction of freshly collected D. obscura showed the presence of compound 3 as the only phenylethanoid. Compound 3 was proven to easily evolve to rengyolone. Due to this instability, and although its presence in plants has been previously reported, the spectroscopical data of 3 are reported herein for the first time. Selective mono-acetylation of compound of 3 led to the active natural compound hallerone (5). The aphid antifeedant (against Myzus persicae) and nematicidal (against root-knot nematode Meloidogyne javanica) activities of these compounds have been evaluated. Here we report for the first time on the aphid antifeedant effects of 1, 3, and 5. Additionally, the nematicidal activity of hallerone (5) is described here for the first time.

Optimization of Insecticidal Triterpene Derivatives by Biomimetic Oxidations with Hydrogen Peroxide and Iodosobenzene Catalyzed by MnIII and FeIII Porphyrin Complexes.

Semisynthetic functionalized triterpenes (4α,14-dimethyl-5α,8α-8,9-epoxycholestan-3β-yl acetate; 4α,14-dimethyl-5α-cholest-8-ene-3,7,11-trione; 4α,14-dimethyl-5α-cholesta-7,9(11)-dien-3-one and 4α,14-dimethyl-5α-cholest-8-en-3β-yl acetate), previously prepared from 31-norlanostenol, a natural insecticide isolated from the latex of Euphorbia officinarum, have been subjected to oxidation with hydrogen peroxide (H2 O2 ) and iodosobenzene (PhIO) catalyzed by porphyrin complexes (cytochrome P-450 models) in order to obtain optimized derivatives with high regioselectivity. The main transformations were epoxidation of the double bonds and hydroxylations of non-activated C-H groups and the reaction products were 25-hydroxy-4α,14-dimethyl-5α-cholesta-7,9(11)-dien-3β-yl acetate (59 %), 25-hydroxy-4α,14-dimethyl-5α-cholest-8-ene-3,7,11-trione (60 %), 4α,14-dimethyl-5α,7β-7,8-epoxycholest-9(11)-en-3-one (22 %), 8-hydroxy-4α,14-dimethyl-5α-cholest-9(11)-ene-3,7-dione (16 %), 12α-hydroxy-4α,14-dimethyl-5α,7β-7,8-epoxycholest-9(11)-en-3-one (16 %), and 4α,14-dimethyl-5α,8α-8,9-epoxycholestan-3β-yl acetate (26 %), respectively. We also investigated the insect (Myzus persicae, Rhopalosiphum padi and Spodoptera littoralis) antifeedant and postingestive effects of these terpenoid derivatives. None of the compounds tested had significant antifeedant effects, however, all were more effective postingestive toxicants on S. littoralis larvae than the natural compound 31-norlanostenol, with 4α,14-dimethyl-5α,8α-8,9-epoxycholestan-3β-yl acetate being the most active. The study of their structure-activity relationships points out at the importance of C3 and C7 substituents.

Discovery and Biomimetic Synthesis of a Phloroglucinol-Terpene Adduct Collection from Baeckea frutescens and Its Biogenetic Origin Insight.

A phloroglucinol-terpene adduct (PTA) collection consisting of twenty-four molecules featuring three skeletons was discovered from Baeckea frutescens. Inspired by its biosynthetic hypothesis, we synthesized this PTA collection by reductive activation of stable phloroglucinol precursors into highly reactive ortho-quinone methide (o-QM) intermediates and subsequently Diels-Alder cycloaddition. We also demonstrated, for the first time, the generation process of the active o-QM by performing dynamic NMR and HPLC-MS monitoring experiments. Moreover, the PTA collection showed significant antifeedant effect toward the Plutella xylostella larvae.

Antifeedant, growth regulatory and biochemical effects of terpenes and phenylpropenes on Spodoptera littoralis Boisduval

Screening the biological activities of plant secondary metabolites on economic pests can lead to discovery new ecofriendly biopesticides. The aim of this work was to evaluate the antifeedant, growth inhibitory and toxic activities of seven monoterpenes, two phenylpropenes and two sesquiterpenes on 2nd larval instar of Spodoptera littoralis. The tested compounds induced a significant antifeedant effect at various concentrations (500, 1000 and 2000 mg/kg), particularly after 6 and 9 days of exposure. Among the tested compounds, trans-cinnamaldehyde, α-terpinene, (−)-citronellal and 1,8-cineole were the most potent antifeedants after the three exposure periods. In general the tested compounds showed remarkable antifeedant activity after 9 days of exposure as their antifeedant indices ranged between 44.0 and 80.1%. On the other hand, the tested compounds drastically inhibited the growth of S. littoralis larvae at the tested concentrations. The larval growth inhibition ranged between 21.4 and 100% with cuminaldehyde, 1,8-cineole and eugenol being the most potent growth inhibitors. Some of the tested compounds caused significantly higher antifeedant and growth inhibitory effects than a reference insecticide, pyriproxifen. In general, the tested compounds showed higher growth inhibition than antifeedant effect. The tested compound also induced S. littoralis larval morality which improved with increasing exposure time and concentration. Cuminaldehyde, 1,8-cineole and (−)-carvone showed highest toxicity with 100.0, 97.0 and 77.0% mortality, respectively, at 2000 mg/kg after 9 days of exposure. Biochemical studies revealed that trans-cinnamaldehyde (IC50 = 0.03 mM), farnesol (IC50 = 0.04 mM) and eugenol (IC50 = 0.06 mM) are potent α-amylase inhibitors. These three compounds also caused significant inhibition of total proteases activity. This is the first report on antifeedant, growth inhibitory and insecticidal activities of the tested compounds on S. littoralis. Moreover, the strong bioactivity reported in this study indicated that these compounds have a potential to be used as bioinsecticides.

Vitis vinifera canes, a source of stilbenoids against Spodoptera littoralis larvae

Stilbenes are constitutively accumulated in grape canes at a high concentration of about 10 g kg−1 DW. Some of these compounds have antimicrobial activity and are involved in grapevine defence in leaves and fruits, acting as phytoalexins. In this work, we studied their insecticidal effects against Spodoptera littoralis larvae by using an extract from grapevine canes containing 27% (w/w) of total stilbenes and the major ones isolated from this extract (E-piceatannol, E-resveratrol, isohopeaphenol, E-e-viniferin and E-vitisin B). The stilbenes isolated from the grapevine extract did not show any significant antifeedant effect or acute toxicity, but they did cause chronic mortality to the larvae population of an important polyphagous pest, S. littoralis. The tetramer, E-vitisin B, appeared to be the most effective compound with LC50 and LC90 values of 134 and 298 µg cm−2, respectively. Significant synergic relationships were found between some stilbenes, resulting in a significant increase in the insecticidal efficacy of the mixture of these substances. Taken together, these results suggest that grapevine canes are a good source of active substances for the development of botanical insecticides.

A potential use of vine-shoot wastes: The antioxidant, antifeedant and phytotoxic activities of their aqueous extracts

One of the biggest challenges for wine producing regions is to create alternatives to increase the added value of the large amount of vine-shoot wastes generated. The antioxidant, antifeedant and phytotoxic activities of vine-shoot aqueous extracts obtained by different extraction methods (Conventional Solid-Liquid Extraction, CSLE; Solid-Liquid Dynamic Extraction, SLDE-Naviglio; Microwave Extraction, ME) have been studied. Because of their higher content of phenolic compounds, CSLE and ME extracts showed a higher DPPH radical-scavenging activities compared with SLDE-Naviglio extracts. Significant antifeedant effects against Leptinotarsa decemlineata were observed for CSLE and ME. None of the extracts had phytotoxic effect against Lactuca sativa germination and radicle growth, but SLDE-Naviglio extracts stimulated the radicule elongation. ME extracts were the most active inhibitors of Lolium perenne germination. These results suggest some potential applications of vine-shoot extracts including cosmetics, nutraceuticals or pharmaceuticals linked to their antioxidant effects, or in organic agriculture because of their antifeedant and allelopathic activities.

Chemical composition and bio-pesticidal values of essential oil isolated from the seed of Heracleum persicum Desf. ex Fischer (Apiaceae)

The present investigation was aimed to analyse the chemical composition of essential oil isolated from Heracleum persicum Desf. ex Fischer and assess its lethal and sub-lethal effects against Tribolium castaneum (Herbst). Essential oil from hydro-distilled seeds of H. persicum was analyzed by gas chromatography-mass spectrometry (GC-MS), and hexyl butyrate (50.58%), octyl acetate (9.80%) and hexyl hexanoate (8.75%) were found as principal constituents. Repellent activity, contact and fumigant toxicity and antifeedant effects of this oil were assessed against the adults of T. castaneum. The essential oil strongly repelled T. castaneum adults even at the lowest concentration (0.035 μL cm-2). Complete repellency (100%) occurred when the highest concentration (0.212 μL cm-2) was applied for 8 h. T. castaneum was very susceptible to H. persicum oil at both contact and fumigant bioassays. In the fumigant toxicity, essential oil killed the larvae, pupae and adults and significantly decreased larvae emerged from treated eggs. LC10 to LC40 values of fumigation adult’s bioassay as sub-lethal concentrations were used to evaluate the antifeedant effects. H. persicum essential oil has significant antifeedant effects on T. castaneum adults and decrease of feeding happened when oil concentrations increased. The results of the present study indicate that essential oil of H. persicum, with wide bio-effects on T. castaneum, is a source of biologically active agents which may potentially prove to be efficient insecticides.

Antifeedant and Larvicidal Effects of Some Phenolic Components of Essential Oils Lasp Lines of Introduction Against Spodoptera littoralis (Boisd.)

In our paper, we have tested 12 simple of phenols and 9 phenolic acids for acute toxicity and feeding inhibition on Spodoptera littoralis larvae. It was found that while the phenolic acids showed little or no effect on acute toxicity, all the tested simple phenols caused larval mortality within 24 hours upon application. Lethal doses were successfully estimated for 11 substances using probit analysis. Thymol and carvacrol showed the highest efficiency, for LD50 were estimated as 20 and 27 μg/larvae, respectively. The tested phenols also showed significantly higher feeding inhibition than phenolic acids. The most significant antifeedant effect was exerted by thymol, where LD50 and LD90 were estimated as 6 and 9 μg/cm2, respectively.

Toxic effects of neem-based insecticides on Pieris brassicae (Linn.)

Four neem-based insecticides, Neemix ® (0.25% EC @ 20 mg azadirachtin/liter), Ecozin ® (3% EC @ 20 mg azadirachtin/liter), Agroneem ® (0.15% EC @ 4.8 mg azadirachtin/liter) and Neem oil (0.25% EC azadirachtin @ 20 mg azadirachtin/liter) and a non-commercial neem leaf powder, were evaluated for oviposition deterrence, antifeedant effect to larvae and toxicity to eggs and larvae of Pieris brassicae (Linn.) on cabbage leaves in the laboratory. The concentrations tested were with in the ranges of recommended field rates. Oviposition deterrence in no-choice, two-choice and six-choice assays, was observed for all the treatments. They exhibited significant ( P < 0.01) oviposition deterrence on P. brassicae when compared with a non-treated control. Cabbage leaves treated with the neem-based insecticides were used as an egg-laying substrate. Numbers of eggs oviposited by P. brassicae adults on treated cabbage leaves were significantly lower then those treated with water, but no significant differences were detected among the neem insecticides. They also deterred feeding by Pieris larvae and exhibited significant antifeedant effects. Larvae of P. brassicae on treated leaves stopped feeding and dropped from the leaf, resulting in no or minimal damage. Direct contact with neem-based insecticides decreased the survival of eggs. Survival of larvae fed for 9 days on leaves treated with neem-based insecticides was reduced to 51%, 49%, 48%, 24% and 18% in the Neem oil, Neemix, Agroneem, Ecozin and neem leaf powder treatments, respectively. Therefore, it can be concluded from the present investigations that neem-based insecticides had oviposition deterrence, antifeedant and toxic effect to P. brassicae.

The dose-dependent responses of Deroceras panormitanum and Oxyloma pfeifferi to potential novel molluscicides

The dose-dependent responses of the slug Deroceras panormitanum and the snail Oxyloma pfeifferi were tested with three novel molluscicides: cinnamamide, copper ammonium carbonate and ureaformaldehyde. Solutions of products were used at concentrations ranging from 0.005% to 1% (active ingredients: 0.05–149 μg/cm 2). In a bioassay, antifeedant effects, mortality, repellence and irritation were investigated. Both species were significantly repelled by cinnamamide and a ureaformaldehyde resin at concentrations of 0.5% and 1%, causing a barrier effect. A significant antifeedant effect on D. panormitanum was also seen with those dose-treatment combinations, whereas only Croptex-Fungex ® at 0.5% and 0.625% had a significant antifeedant effect on O. pfeifferi. In comparison to the untreated compost, the accumulated leaf damage on treated compost was significantly reduced by all three products at concentrations of 0.5% and above. The behavioural software EthoVision was used for an automated analysis of the behavioural response of D. panormitanum to the irritant effect. All dose-treatment combinations of 0.1% and above significantly reduced the moving activity of the slug, accompanied by severe weight loss and significant increases in mortality with cinnamamide and a ureaformaldehyde resin at 0.5% and 1%. Egg development was completely suppressed at concentrations as low as 0.05%. Significant delays in egg development time were observed with all three molluscicides at concentrations as low as 0.005%. The implications for an integrated control strategy of these pest species are discussed.

Effects of three neem-based insecticides on diamondback moth (lepidoptera: plutellidae)

Three commercial neem-based insecticides, Agroneem™, Ecozin™, and Neemix™, were evaluated for oviposition deterrence, antifeedant effect to larvae, and toxicity to eggs of the diamondback moth, Plutella xylostella L., in the laboratory. All three neem-based insecticides did not exhibit significant oviposition deterrence on P. xylostella. When cabbage leaves were used as an egg-laying substrate, numbers of eggs oviposited by P. xylostella adults on the cabbage leaves treated with the three neem-based insecticides were not significantly different from those treated with water. However, when aluminum foil sheets coated with cabbage juice residue were treated with the three insecticides and were used as egg-laying substrates, significantly fewer eggs were found on the aluminum foil sheets compared with those treated with water. When eggs were treated with Agroneem, Ecozin and Neemix, 61.6%, 66.2%, and 75.2% of P. xylostella eggs developed to neonates, respectively, although the larval hatching rates in the treatment of Neemix were not significantly different from that in water control (81.2%). All larvae of P. xylostella fed on the leaves treated with the three neem insecticides died on or before day 7 compared with 70–74% larvae surviving to adults in the water control. All three neem insecticides exhibited significant antifeedant effect, and P. xylostella larvae on treated leaves quickly stopped feeding and dropped off treated leaves, resulting in no or minimal damage on the treated cabbage leaves. P. xylostella larvae that fed on neem insecticide treated leaves were significantly smaller (0.012–0.016mg/larva, 13.5–14.8mm in length, and 2.0–2.5mm in diameter) compared with those fed on water-treated leaves (0.058mg/larva, 30.2mm in length, and 4.8mm in diameter).

Insect growth‐reducing and antifeedant activity in Eastern North America hardwood species and bioassay‐guided isolation of active principles from Prunus serotina

Abstract1 Thirty extracts of wood and bark of hardwood trees from Eastern North America were examined for insect growth‐reducing activity in a bioassay with European corn borer, Ostrinia nubilalis, and an antifeedant bioassay with the rice weevil, Sitophilus oryzae.2 Nine of the bark extracts and four of the wood extracts showed significant growth reducing effects at 0.5% in meridic diets, whereas only two bark extracts and one wood extract showed significant antifeedant effect at the same concentration.3 Slower growing tree species were more biologically active than fast growing ones. Isolation of the bioactive compounds in one of the active species, Prunus serotina, showed that naringenin, its derivative methoxynaringenin, and eriodictyol were responsible for the antifeedant effects.

Secretory avocado idioblast oil cells: evidence of their defensive role against a non‐adapted insect herbivore

AbstractWe tested the hypothesis that avocado idioblast oil cells play a defensive role against herbivorous insects. Toxicities of the intact avocado idioblast oil cells and the extracted idioblast oil were compared for three insect herbivores. Spodoptera exigua (Hübner) larvae are generalists that do not feed on avocados. By contrast, Sabulodes aegrotata (Guenée) and Pseudoplusia includens (Walker) larvae are generalist herbivores that readily feed on avocados. All bioassays were performed at a naturally occurring concentration of idioblast oil cells (2% w/w). Choice experiments showed that S. exigua larvae avoided diet treated with avocado idioblast oil cells and consume more control than treated diet. In contrast, idioblast oil cells had no significant antifeedant effects on the adapted S. aegrotata and P. includens larvae. Subsequent experiments designed to assess resistance mechanisms separated pre‐ingestive (behavioral) and post‐ingestive (physiological) effects of the avocado idioblast oil cells, and the extracted idioblast oil, on the two adapted herbivores. Post‐ingestive adaptation was the mechanism that allows feeding. Because the impact of the avocado idioblast oil cells was greatest on the performance of non‐adapted S. exigua, additional experiments determined that larvae fed diet containing the oil cells had higher mortality and reduced larval growth compared to controls. Developmental times were significantly prolonged for the survivors. Thus, increased mortality, reduced developmental rates, and antifeedant activity in the non‐adapted insect indicate that defense against non‐adapted herbivores may be an important function of idioblast cells in avocados.

Antifeedants to Armyworms, Spodoptera litura and Pseudaletia separata, from Bitter Gourd Leaves, Momordica charantia

Bitter gourd, Momordica charantia, was less palatable to two species of armyworms, Spodoptera litura and Pseudaletia separata, than two other cucurbitaceous plants. A methanol extract of M. charantia leaves inhibited feeding of the armyworm larvae. The two most active fractions obtained by silica gel chromatography were purified by HPLC. Momordicine II, a triterpene monoglucoside, was identified as an antifeedant compound from the more active of these fractions. The second active fraction led to the isolation of a new triterpene diglucoside. Fresh leaves of M. charantia contained ca. 0.3% of momordicine II. Momordicine II showed significant antifeedant effects on P. separata at concentrations of 0.02, 0.1, and 0.5% in artificial diets. Momordicine II caused a significant feeding reduction in S. litura only at the highest concentration (0.5%) tested. The difference in feeding response of the two armyworms to momordicine II may be related to the diversity in their host range.

Survival, Growth, Fecundity, and Behavior of Helicoverpa armigera (Lepidoptera: Noctuidae) on Pigeonpea and Two Wild Cajanus Species

Survival, growth, fecundity, and behavior of Helicoverpa armigera (Hubner) were compared on pods of cultivated pigeonpea, Cajanus cajan (L.) Millspaugh, and 2 wild species, C. scarabaeoides . (L.) Thouars, and C. platycarpus (Bentham) van der Maeson. Larval survival was 21% on C. scarabaeoides , 56% on C. platycarpus , and 78% on C. cajan . Pupal survival was high on all 3 Cajanus species. Seven-day-old larvae reared on C. scarabaeoides pods weighed significantly less at 18 d, took longer to pupate and produced significantly smaller pupae than those fed on C. cajan pods. Larval period and weight, and pupal weight when reared on C. platycarpus were intermediate and significantly different from the other 2 species. Differences in pupal duration were not significant between larvae reared on the 3 Cajanus species. Larvae on C. scarabaeoides spent significantly less time feeding and significantly more time off the pod than larvae on the oilier 2 species. Acetone extracts of C. cajan and C. platycarpus pods had a significant feeding stimulant effect on H. armigera larvae, whereas extracts from C. scarabaeoides pods had no effect. Water extract of C. scarabaeoides pods had a significant antifeedant effect though similar extracts from C. cajan and C. platycarpus pods had no effect. Application of these results to resistance breeding programs is discussed.

The effect of cypermethrin on the feeding of mustard beetles Phaedon cochleariae (F.)

SummaryCypermethrin deposits on sprayed (3, 6, 9, 12 and 15 g ha‐1) radish leaves caused a significant antifeedant effect on third instar larvae and adults of mustard beetles.There was a significant inverse relationship between feeding and dose for both stages. In the case of adults on deposits of 1, 3 and 6 g hafeeding was reduced by 60–75% but no mortality was recorded. Much less uniform feeding was associated with higher application rates (9, 12 and 15 g ha‐I) with low mortality at the two highest doses. The mean areas of the individual holes eaten by larvae or adults in either control or treated leaves, did not differ significantly. The number of holes eaten was negatively related to application rate. The antifeedant effect was observed with low concentration of both technical and formulated cypermethrin.