Neem Insecticide Research Articles

Resistance of Nilaparvata lugens to Fenobucarb and Imidacloprid and Susceptibility to Neem Oil Insecticides

This study aims to monitor and determine the level of resistance of N. lugens to fenobucarb and imidacloprid, to analyse of the specific activities of asetylcholinesterase, Glutation S-Transferase, esterase, and to determine sensitivity of resistant N. lugens to the neem oil. Resistance tests were conducted on a field population from Cipunagara, Subang, West Java, Indonesia, and a standard population originating from Banyuwangi, East Java, that was obtained from the Indonesian Center for Rice Research. Synthetic and neem Insecticides were applied using the leaf-stem dipping method. The resistance ratio obtained by comparing the LC50 value of the field population with the standard. The test insects were considered to be resistant to synthetic insecticide if they had a resistance ratio (RR) of more than 4, indicated resistance if RR ≥1, and susceptible to neem if has RR <1. The results of the research showed that the N. lugens population of Cipunagara indicated resistance to fenobucarb (RR = 2.43), while it was clearly resistance to imidacloprid (RR = 13.95). Specific activities of the acetylcholinesterase and Glutathione S-Transferase of the N. lugens Cipunagara populations were higher than the standard, while the esterase specific activity was lower. These two enzymes are responsible for the resistance of N. lugens to fenobucarb and imidacloprid. Nevertheless, the N. lugens population of Cipunagara was susceptible to neem (RR <1) that never been reported before. Therefore, it is important to know the change in the sensitivity of the target and the metabolic pathway of the insecticide used to manage insect resistance.

Repellency Effect of Prepared Neem Tree Leaves Smoke against Mosquito

The study was design to evaluate the smoke repellency effect of prepared neem leaves, against mosquito. The dried neem powder was used for making the insecticide, 10 g of powdered leaves sample was weight into a 200 ml beaker, and 5.0 g of starch was weight and added to the leave sample in the beaker. The mixture was stirred and 5.0 ml of distilled water was added gradually to the mixture in little quantity while stirring. The beaker with wet insecticide mixture was dried in an oven until a constant weight was obtained. The prepared neem insecticide was distributed among the households to use at night, to substitute synthetic insecticides. The users were randomly selected within the study area. The data was collected based on the time of application, number of bites receive before and after the application this was done based on 0-5 rating scale. The result revealed that the prepared insecticide is 100% effective though the effectiveness is dependent to time taken after application. The questionnaire was also used to assess the view of the users on the adverse effect they experienced upon the exposure to neem tree leaves prepared sample. The study has been concluded that neem leaves smoke is effective in repelling mosquito, and it can be an alternative to the synthetic insecticides hence it is safe for the users and the environment.

Synthesis and validation IPM technology and its economic analysis for bottle gourd (Lagenaria siceraria)

The field experiment was conducted (2016-18) at Varanasi, Mirzapur and Deoria districts of Uttar Pradesh with a view to study the validation and economic viability of adaptable IPM technology in a farmers’ led approach. The IPM technology that synthesized comprising seed treatment with Trichoderma viride @5 g/kg of seed; installation of cue lure traps (MAT) for fruit flies @10/acre; raking of soil for exposing fruit fly pupae and removal of weeds, need based application of Bacillus thuringiensis @2 g/litre against Sphenerches caffer; need based spraying of Azadirachtin based neem insecticide @10 ml/litre and Imidacloprid 17.8SL @0.33 ml/litre of water for mirid bugs and whiteflies; fungicide Cymoxanyl 8WP+Mancozeb 64WP @2.5 g/litre against downy mildew were found effective in reducing the incidence of pests and minimizing the yield losses. The adoption of IPM technology, apart from lowering the incidence of major pests, also resulted in reducing the number of chemical sprays to 5–7 from 14–18 in non-IPM fields in a season with higher bottle gourd yields of 28, 29.5 and 21.7 tonnes/ha in IPM and 17.5, 18.1 and 10.9 tonnes/ ha in non-IPM fields and with marginally higher cost benefit ratio of 1:1.91, 1:2.05 and 1:2.41 in IPM than 1:1.14, 1:1.19 and 1:11, respectively in non-IPM. On an average, IPM farmers had an average net return of ₹ 145472/ha with C:B ratio of 1:2.09 as compared to the non-IPM farmers with net return of ₹ 20992/ha with a C:B ratio of 1:1.15.

INSECTICIDAL ACTIVITY OF BIO-SILVER AND GOLD NANOPARTICLES AGAINST PERICALLIA RICINI FAB.(LEPIDAPTERA: ARCHIDAE)

A laboratory experiment was conducted to evaluate the impact of silver aqueous solution, gold aqueous solution, pungamoil, pungamoil-based silver nanoparticles (PO-AgNPs) and pungamoil-based gold nanoparticles (PO-AuNPs), vijayneem against Pericallia ricini larval mortality, development and fecundity and gravimetric analyses. The results showed that Ag+ aqueous solution as well as pungamoil-based gold nanoparticles caused more mortality than commercial neem insecticide (vijayneem). Aqueous solutions of Ag+ and Au+ drastically reduced the body weight of P. ricini larvae. PO-AgNPs and POAuNPs treatment drastically enhanced the food consumption, assimilation but reduced the conversion, subsequently affecting growth. Distinct difference was noticed between PO-AgNPs and PO-AuNPs treatments in larval, pupal and adult developmental periods, fecundity and hatchability. It is recommended to integrate PO-AgNPs and PO-AuNPs in pest management; however, field evaluations and bio-safety assessments were imperative before the utilization of these bio-nanoparticles were recommended.

Toxic effects of neem based insecticides on the fitness of Helicoverpa armigera (Hübner)

The toxic effects of neem based insecticide products (Neemarin (0.15% EC azadirachtin), Neemazal (1% EC azadirachtin), Neemix (0.25% EC azadirachtin) and Neem oil (1% EC azadirachtin)) were evaluated on Helicoverpa armigera (Hübner) using a life table approach. Additional studies were done to determine the effects of the neem insecticides on the development time of immature stages. The survivorship was maximum (46 days) for Neemazal treated groups and 42 days in untreated groups. Life expectancy was highest (26.3 days) with Neem oil at very first day of age while it was 19.9 in controls. All the eggs hatched when treated with Neemarin, Neem oil and control while, 94% hatched when treated with Neemazal. The potential fecundity was lowest with Neemix (378 females/female/generation) and highest in the untreated control (1034). Daily fecundity rate (mx) was significantly greater (143 offspring/day) in the control than 58 offspring/day with Neemazal. Intrinsic rate of increase was lowest (0.026day−1) with Neemazal as compared to unexposed groups (0.041day−1). The time taken to complete one generation was 38.8 days in untreated groups, while it was prolonged to 40.6 days with Neemazal and reduced to 37.4 days with Neemarin. Doubling time was prolonged to 11.7 days with Neemazal while it was 6.4 days in unexposed groups. Development of immature stages was increased to 37.6 days with Neemazal while reduced to 32.3 days with Neemix as compared to 35.6 days in unexposed controls. It is concluded that the different neem insecticides had widely varying adverse effects on the fitness parameters of H. armigera. Impacts such as reduction in fecundity, reproductive rates, immature development and adult emergence may change the occurrence period of this pest in relation to crop and the crop may be escaped pest damage. Hence, are suitable for integration into an IPM program of this pest.

Effect of Neem Pesticide (Achook) on Midgut Enzymatic Activities and Selected Biochemical Compounds in the Hemolymph of Lesser Mulberry Pyralid, Glyphodes Pyloalis Walker (Lepidoptera: Pyralidae)

Abstract Synthetic organic compounds and those of plant origin used in insect pest control are known to affect digestive enzymes and biochemical compounds. The lesser mulberry pyralid Glyphodes pyloalis Walker is a monophagous and dangerous pest of mulberry that has been recently observed in Guilan province, northern Iran. In this study the effect of the neem formulation, Achook (0.03% azadirachtin) was studied on nutritional physiology and gut enzyme activity of the lesser mulberry pyralid G. pyloalis. The LC25, LC50, and LC90 values on 4th instar larvae were estimated as 113.6, 256.84, and 1,210.02 ppm, respectively. The neem insecticide exhibited a significant antifeedant activity when used at the highest concentration. When G. pyloalis larvae were provided with mulberry leaves treated with the neem extract, all nutritional indices, except approximate digestibility, decreased. Neem was found to affect digestive enzyme activities in the midgut of treated larvae. When larvae were fed on treated leaves, biochemical compounds in the hemolymph, such as protein, lipid, and glucose decreased but the amount of uric acid increased compared with the control

Bioprospecting: Experimental Investigation on the Comparative Efficacy of Neem Aqueous Extract and Synthetic Insecticide for the Control of Termites

For a sustainable environmental future, the world ecosystem needs to be free of toxic residues. A bioprospecting strategy involving comparative analysis on the efficacy of neem aqueous extract and a synthetic insecticide in the control of termites was experimented. Soldier and Worker castes were exposed to aqueous neem extract and insecticide treatment at dif- ferent concentrations of 5%, 7.5%, 10% and 15% and replicated 3 times. From the results of the study, aqueous neem extract recorded a higher mortality rate than the synthetic insecticide. When their means were compared using Analysis of Variance and T-test, aqueous extract treatment was found to be more significant and more toxic in the control of termites than the synthetic insecticide. In view of the risk of environmental contamination by synthetic insecticides, insecticides of plant origin such as Neem which is more effective, cheap and easily biodegradable should be used in controlling termites.

Effects of neem based insecticides on Plutella xylostella (Linn.)

A study on the effect of neem based insecticides on Plutella xylostella (Linn.) was conducted under laboratory conditions. Three neem based insecticides, Neemazal®T/S (1% EC @ 100 mg azadirachtin/liter), Neemix® (0.25% EC @ 25 mg azadirachtin/liter) and Neemexcel® (0.15% EC @ 15 mg azadirachtin/liter) were evaluated for their effects on biological parameters, pupal weight and nutritional indices of P. xylostella on cauliflower leaves. The concentrations tested were 5, 10, 15 and 20 ppm of active ingredient. The highest concentrations (15 and 20 ppm) of all three neem insecticides significantly affected the biological parameters of P. xylostella when compared with the lowest concentrations (5 and 10 ppm) and the non-treated control, Neemazal being the most effective. Results showed that development time was concentration dependent for all the neem insecticides. Neemazal significantly prolonged the development time at a higher concentration when compared with the other neem insecticides and non-treated control. Neemazal significantly affected the biological parameters and reduced the weight of pupa at 15 and 20 ppm concentration due to reduced consumption and utilization of food. However, no significant difference was detected between these two concentrations i.e. 15 and 20 ppm of Neemazal. Therefore, from the overall findings it could be concluded that the concentration of Neemazal i.e. 15 ppm could be utilized in IPM programs for P. xylostella in cauliflower crops.

Neem based Integrated Approaches for the Management of Tea Thrips Scirtothrips dorsalis Hood (Thripidae: Thysanoptera) in Tea

Tea thrips, Scirtothrips dorsalis Hood (Thripidae: Thysanoptera), has been the most destructive pest of tea in North East India since last few decades. In order to reduce the load of the synthetic chemicals in tea vis-a-vis their deleterious effect, integration of biopesticides, synthetic pesticides along with effective spraying strategies, have been attempted. The anti-insect property of “neem”, Azadirachta indica A. Juss. (Meliaceae) has been used to solve many pest problems. Two field trials were conducted between May and June 2008 at Red Bank Tea Estate, Jalpaiguri, West Bengal, India following randomized block design against tea thrips, S. dorsalis. In one experiment, different azadirachtin concentrations (300, 1,500, 3,000, 10,000 and 50,000 ppm) at different doses (1:200, 1:300, 1:500, 1:1,000 and 1:1,500) were evaluated to find out the relationship between azadirachtin concentration and its bioactivity against S. dorsalis. At 50,000 ppm azadirachtin concentration 82% control of reduction in thrips population could be attained, whereas at 3,000 and 10,000 ppm, gave 60–73% reduction and 300 and 1,500 ppm <60% control was possible. Therefore, azadirachtin concentration and its dilutions are the major criteria to determine the bioactivity against tea thrips. In another field experiment, a neem formulation alone and in combination with Tea Research Association recommended and reduced dose of endosulfan and monocrotophos were tested. Treatments with combined formulations (neem + insecticide) recorded significant reduction in S. dorsalis incidence even at reduced doses (1:600 and 1:800), as compared to sole application of neem or synthetic insecticide at recommended doses. Azadirachtin concentrations and their bioactivity, effective combinations and dose of the insecticides along with their formulations in controlling S. dorsalis have been presented and discussed.

Eficiência e efeitos subletais de nim sobre Bonagota salubricola (Meyrick) (Lepidoptera: Tortricidae)

O objetivo deste trabalho foi avaliar a eficiência e os efeitos subletais de um inseticida à base de nim (10 g.L-1 de azadiractina A) sobre a lagarta-enroladeira Bonagota salubricola em laboratório. Nos bioensaios, foi utilizado o produto à base de azadiractina NeemAzal-T/S® nas concentrações de 0,06%; 0,09%; 0,12%; 0,16%; 0,18% e 0,20% do produto comercial (p.c) e uma testemunha (água destilada). A dieta artificial foi cortada em cubos e imersa nas caldas das respectivas concentrações do produto, e, em seguida, lagartas recém-eclodidas foram transferidas para tubos de vidro, contendo os cubos de dieta tratados. Quando a dieta artificial foi tratada com concentração de 0,20% do produto comercial, houve 100% da mortalidade aos 6 dias após a inoculação. Por outro lado, as concentrações de 0,16 e 0,18% prolongaram a fase larval, reduziram a viabilidade de pupas e afetaram negativamente a fecundidade do inseto.

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.

Bioactivity of synergized neem (Azadirachta indica) and potentated insecticides on buffo regularis as a nontarget organism

Bioactivity of synergized neem (Azadirachta indica) and potentated insecticides on buffo regularis as a nontarget organism

Comunicação científica eficiência de inseticidas à base de nim no controle de Grapholita molesta (Busck, 1916) (Lepidoptera: Tortricidae)

O objetivo foi avaliar a eficiência de inseticidas à base de nim no controle da mariposa-oriental G. molesta em laboratório. A dieta artificial foi cortada em cubos e imersa nas caldas dos respectivos tratamentos; em seguida, lagartas recém-eclodidas foram transferidas para tubos de vidro, contendo os cubos de dieta tratados. Os produtos testados foram: NeemAzal-T/S®, Dalneem emulsionável®, Organic Neem® e Natuneem Agrícola® na concentração de 0,5% do produto comercial (p.c.) em comparação com o inseticida químico fenitrotion (Sumithion 500 CE®) a 0,15% p.c. e uma testemunha (água). Os inseticidas NeemAzal-T/S® e Dalneem emulsionável® apresentaram a mortalidade de 100% das lagartas, sendo eficientes no controle do inseto em condições de laboratório. Organic Neem® e Natuneem Agrícola® demonstraram menor atividade inseticida, ocasionando mortalidade de 73,5% e 22,5%, respectivamente; no entanto, afetaram significativamente a viabilidade larval.

Effectiveness of Neem (Azadirachta indica) insecticides against Brassica pod midge (Dasineura brassicae Winn.)

The efficiency of the botanical insecticide (BI) NeemAzal T/S (containing 1% Azadirachtin A), on the basis of azadirachtin applied in a dose of 20 g a.i. ha−1 against Brassica pod midge (Dasineura brassicae), has been monitored for 4 years. The biological efficiency of BI was compared with the efficiency of some synthetic insecticides. It was ascertained that BI was very efficient in decreasing the number of damaged oilseed rape pods (ranging from 56.5 to 85.9% compared to untreated plants) and its efficiency was comparable with synthetic insecticides based on Chloronicotinyl (Thiacloprid) and Neonicotinoid (Acetamiprid). BI’s efficiency was, in some years, even significantly higher compared to pyrethroid (λ-cyhalothrin). The high biological efficiency of azadirachtin that we ascertained was significantly reflected in increasing potential crop yields. The yield increase of azadirachtin ranged between 9.3 and 19.4% compared to the control sample. Azadirachtin showed the highest yield for the whole time of experimentation, and in some years the yield increase was significantly higher compared to some synthetic agents.

Efecto de insecticidas a base de neem ( Azadirachta indica A. Juss) en parasitoides

Azadirachta indica A. Juss (Meliaceae) is an indian tree, commonly called the neem tree. It has many useful compounds that act as insecticide. Neem insecticides have in their composi-tion azadirachtin, a tetranortriterpenoid plant limonoid which can be isolated from the seeds of the neem tree(Mordue &amp; Blackwell, 1993). Azadirachtin is also termed Azadirachtin A (Rembold, 1989).

Effects of a neem-based insecticide on different immature life stages of the leafminerLiriomyza sativae on tomato

The effects of the commercially available neem insecticide NeemAzal-T/S® (neem) (1% azadirachtin) onLiriomyza sativae (Diptera: Agromyzidae) were studied on tomato in Bangkok, Thailand. Neem emulsions were sprayed on the aerial plant parts at five concentrations (from 0.001% to 0.010% a.i.); different aged residues (0, 1, 3, 5, and 7 days) were tested, in both controlled environment rooms and in greenhouses. Irrespective of the residual age of the application, no significant effects on oviposition or egg hatch were detected. However, neem drastically increased larval mortality at the higher concentrations tested. The L1 and L2 larvae were most susceptible. Irrespective of concentration, larval mortality or inhibition of adult eclosion decreased much faster in greenhouses than in controlled environments with artificial light. Nevertheless, our results suggest that neem has potential to controlL. sativae in netted greenhouses.

EFFECTS OF AZADIRACHTIN ON THE SUNN PEST, EURYGASTER INTEGRICEPS PUT. (HETEROPTERA, SCUTELLERIDAE) IN THE LABORATORY

To investigate the effect of azadirachtin on different stages of the sunn pest, Eurygaster integriceps Put. (Het., Scutelleridae) in the laboratory, a commercial neem insecticide (NeemAzal T/S) was applied at dose of 0.5 % by dipping insects. No effect was observed for 1. instar nymphs at 1 day after application, although adults had slightly effect (20 %). Adults and nymphs were infl uenced 7 days after the treatment and mortality rates for adults and nymphs were recorded 44.0 and 51.9 %, respectively. The hatching of treated eggs was reduced than control. These results indicate that NeemAzal T/S may be used in integrated sunn pest management, but should be evaluated for fi eld efficacy.

Effects of a Commercial Neem Insecticide ((Neem AzalTM-T/S) on Early and Late Developmental Stages of the Beet Armyworm, Spodoptera exiqua (Hubner) (Lepidoptera: Noctuidae)

Effects of a Commercial Neem Insecticide ((Neem AzalTM-T/S) on Early and Late Developmental Stages of the Beet Armyworm, Spodoptera exiqua (Hubner) (Lepidoptera: Noctuidae)

Aquatic mesocosm assessments of a neem (azadirachtin) insecticide at environmentally realistic concentrations—2: zooplankton community responses and recovery

A neem-based insecticide, Neemix 4.5, was applied to forest pond enclosures at environmentally realistic concentrations (i.e., below the worst-case expected environmental concentration of 35μgL−1). Crustacean zooplankton communities were examined by multivariate ordination (nonmetric multidimensional scaling) and time-course analyses of population trends among indicator taxa over two field seasons to determine application effects on community structure and recovery patterns. Significant effects on zooplankton community structure were detected at all main test concentrations (n=5) of 28, 17, and 10μgL−1 azadirachtin. There was also evidence of adverse effects on zooplankton communities at an auxiliary test concentration (n=2) of 5μgL−1 azadirachtin. Community-level effects resulted primarily from reductions in adult copepods with short-term, reciprocal increases in cladocerans. Copepod nauplii were not significantly affected. Response patterns suggested that the reductions in adult copepods resulted from growth-regulating effects of the active ingredient azadirachtin, or other neem compounds, and not from formulation ingredients. There was no evidence of recovery among adult copepods within the season of application. At the beginning of the second sampling season, there were apparent carryover effects similar to the community responses in the previous year. By the end of the second season, there was evidence indicating recovery of community structure at the two lower test concentrations of 10 and 17μgL−1, but not at 28μgL−1. The selective toxicity to adult copepods is problematic in that this group has a relatively long life cycle (1 year), contributes a major component of zooplankton biomass and respiration, and occupies critical functional guilds within zooplankton food web structures. Mitigation measures such as reductions in application rates and efforts to avoid deposition of sprayed materials on water bodies will be required to reduce the risk of harmful effects on zooplankton communities of forest ponds and other shallow, standing-water bodies.

Effects of two different neem products on different stages of Nezara viridula (L.) (Heteroptera, Pentatomidae)

In this study, the effects of two different commercial neem insecticides (NeemAzal T/S and Neem Oil) were determined on different stages of Nezara viridula (L.) (Heteroptera: Pentatomidae) under laboratory conditions. Neem Azal and Neem Oil were applied at concentrations of 0.5 % and 2 %, respectively. Mortality was recorded after 3, 7 and 14 days for nymphs and adults; 7 and 14 days for old (4-day-old) eggs; and 14 days for newly laid (one-day-old) eggs. Both products have no significant effect on adults and newly laid eggs. However Neem Oil was found to be more effective than NeemAzal T/S on nymphs and on old laid eggs after 7 and 14 days. It can be concluded that both neem products have potential for insecticidal efficacy (approximately 60 %) against nymphs of N. viridula. at concentrations recommended by manufacturers for registered pests.