Side Effects of Different Doses of Azadirachtin on Predatory Mite Metaseiulus Occidentalis (Nesbitt) (Acari: Phytoseiidae) Under Laboratory Conditions (original) (raw)
Related papers
2010
The preparation of effective neem-based bioinsecticides (Azadirachta indica A. Juss.) requires the extraction and concentration of its active ingredients, given that they are not found in large quantities in a natural form. Simple cold press, methanolic cold press (methanolic), Soxhlethexane (hexanic) and aqueous (aqueous) neem extracts were compared with respect to the concentration of azadirachtin (AZA) and its insecticidal effectiveness against Aphis gossypii Glover, as well as possible toxic effects on Ixora coccinea L. The experimental design was completely randomized. An analysis of variance was made with the data and the means were compared with the Tukey test (p£0.05). Analyses of extracts by HPLC showed significantly different concentrations (2478, 565, 422 and 150 ppm) of AZA in the methanolic, hexanic, oily and aqueous extracts. The bioassay to determine the insecticidal effect and the phytotoxicity of the extracts consisted of exposing 10 nymphs of A. gossypii to leaves of I. coccinea treated with each extract to doses of 0.01, 0.1 and 0.2 mg f AZA in 5 cm 2 , and a control with water, with three replicates. Mortality was measured at 24, 48 and 72 h. Only the oily extract produced lesions in 35 % of the treated leaf area with moderate damage and level 5 phytotoxicity in I. coccinea. Significant differences were found in the mortality of A. gossypii per type of extract, time and dose, as well as in the interactions dose time and dose type of extract. The extract with the highest insecticide potential was the methanolic (0.2 mg AZA), with 100 % mortality at 48 and 72 h (p£0.0001). The simultaneous application of methanol and cold press extracts more AZA from the seed of A. indica, promoting a higher insecticidal activity.
Chemosphere, 2007
Extracts of neem (Azadirachta indica A. Juss) are used in the developing world for many purposes including management of agricultural insect pests. The effects of different neem extracts (aqueous (NSKEaq), ethanol (NSKEeth) and hexane (NSKEhex)) on mortality, survival and weight of the brown planthopper, Nilaparvata lugens (Stål) (BPH) (Homoptera: Delphacidae) third and fourth nymphal instars were investigated. When fed rice plants treated with neem derivatives in bioassays, the survival of BPH nymphs is affected. Comparisons were made with the pure neem limonoid, azadirachtin (AZA) to ascertain its role as a compound responsible for these effects. AZA was most potent in all experiments and produced almost 100% nymphal mortality at 0.5 ppm and higher concentrations. When higher concentrations were applied, the effects appeared shortly after treatment and mortality was higher. Many insects died after remaining inactive for several days or during prolonged moulting. At lower concentrations, if moulting was achieved, disturbed growth and abnormalities were then likely to occur in the moulting process. Nymphs that were chronically exposed to neem extract showed a reduction in weight (45-60%). The results clearly indicate the simple NSKE (aqueous, ethanolic or both), containing low concentrations of AZA, can be used effectively to inhibit the growth and survival of BPH.
Safety evaluation of neem ( Azadirachta indica) derived pesticides
Journal of Ethnopharmacology, 2004
The neem tree, Azadirachta indica, provides many useful compounds that are used as pesticides and could be applied to protect stored seeds against insects. However in addition to possible beneficial health effects, such as blood sugar lowering properties, anti-parasitic, anti-inflammatory, anti-ulcer and hepatoprotective effects, also toxic effects are described. In this study we present a review of the toxicological data from human and animal studies with oral administration of different neem-based preparations. The non-aqueous extracts appear to be the most toxic neem-based products, with an estimated safe dose (ESD) of 0.002 and 12.5 g/kg bw/day. Less toxic are the unprocessed materials seed oil and the aqueous extracts (ESD 0.26 and 0.3 mg/kg bw/day, 2 l/kg bw/day respectively). Most of the pure compounds show a relatively low toxicity (ESD azadirachtin 15 mg/kg bw/day). For all preparations, reversible effect on reproduction of both male and female mammals seem to be the most important toxic effects upon sub-acute or chronic exposure. From the available data, safety assessments for the various neem-derived preparations were made and the outcomes are compared to the ingestion of residues on food treated with neem preparations as insecticides. This leads to the conclusion that, if applied with care, use of neem derived pesticides as an insecticide should not be discouraged.
2006
Among the economic important Liriomyza spp., Liriomyza sativae causes substantial damage to tomatoes for instance infestation strongly reduces the photosynthetic activities resulting in high yield losses. The studies were conducted to investigate the effects of biopesticides (NeemAzal ®-U and NeemAzal ®-T/S) and biorational pesticides (Spinosad and Abamectin) on L. sativae and its two parasitoids, Opius (Opiothorax) chromatomyiae and Neochrysocharis formosa both under laboratory and greenhouse conditions. All tested NeemAzal ®-U (17% Azadirachtin) concentrations applied as solutions to the substrate of potted tomatoes had very low effects on oviposition and egg hatch. However, strong systemic effects were observed in different larval stages attaining mortalities up to 100% when a high dosage of soil drenching solution (3.0 g NeemAzal ®-U/lw) was implemented. The early instar (L1) larvae were found to be most susceptible to all dosages tested. Significant efficacy of NeemAzal ®-U could be measured up to one week post-application. Leafminer prepupae moving to pupate in treated soil suffered from a very high mortality which resulted in only very few adults emerging even when the lowest NeemAzal ®-U concentration of 0.75 g/lw was used. The direct effects of soil treatment were elucidated with high mortality values subsequent to instant soil treatment of prepupae and pupae reared on untreated plants. NeemAzal ®-T/S (1% Azadirachtin) was applied on aerial plants parts with five increasing concentrations (1 ml, 3 ml, 5 ml, 7 ml and 10 ml/lw), and different ages of residues. Irrespective of the residual age of the topical application, no significant effects of NeemAzal ®-T/S was found on oviposition and egg hatch. However, NeemAzal ®-T/S strongly induced immature mortality at higher dosage rates. The L1 and L2 larvae were found to be most susceptible. The larval mortality reached up 100% and completely inhibited adult eclosion. Irrespective of NeemAzal ®-T/S concentrations its efficiency in terms of induced larval mortality or inhibition of adult eclosion decreased much faster in greenhouses than in an air conditioned environment. Nevertheless, the results suggest that NeemAzal ®-T/S applied topically has a high potential to control L. sativae in netted greenhouses in the humid tropics. In comparative study, NeemAzal ®-T/S and Success ® caused no effects on oviposition and egg hatch compared to untreated control (water treatment). Summary II Irrespective of tested dosages, Abamectin strongly reduced egg deposition and severely affected embryonic development. All three pesticides severely affected the survival of immature stages (i.e. L1, L2 and L3) of L. sativae, with mortality up to 100% for fresh (one day old) residues and adult eclosions were completely stopped. Success ® and Abamectin had a longer persistency (up to 14 days) both under laboratory and greenhouse conditions compared to NeemAzal ®-T/S, the activity of which decreased significantly with residual age under greenhouse conditions.
Egyptian Academic Journal of Biological Sciences, F. Toxicology & Pest Control, 2017
The journal of Toxicology and pest control is one of the series issued twice by the Egyptian Academic Journal of Biological Sciences, and is devoted to publication of original papers related to the interaction between insects and their environment. The goal of the journal is to advance the scientific understanding of mechanisms of toxicity. Emphasis will be placed on toxic effects observed at relevant exposures, which have direct impact on safety evaluation and risk assessment. The journal therefore welcomes papers on biology ranging from molecular and cell biology, biochemistry and physiology to ecology and environment, also systematics, microbiology, toxicology, hydrobiology, radiobiology and biotechnology. www.eajbs.eg.net Provided for non-commercial research and education use. Not for reproduction, distribution or commercial use.
Journal of AgriSearch
Farmers in general use various pesticides for management of mites so it is very important to make comparative study of both conventional and novel acaricides before recommendation to farmers. Six acaricides were screened by leaf dip method and their LC50 value and relative toxicity was worked out by taking the LC50 of Dicofol as standard check. The mortality count was recorded and corrected mortality was calculated. The experiment was carried out in Acarology Laboratory, Department of Entomology and Agricultural Zoology, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi to test the relative toxicity of seven pesticides Propargite 57EC, Clofentazine 50SC, Cyflumetofen 20EC, Fenpyroximate 5EC, Dicofol 18.5EC, Azadirachtin 0.03EC and water as control against mites in laboratory conditions The experiment was conducted with objective to test the efficacy of acarides in laboratory condition.
Neem: An Eco-Friendly Botanical Insecticide in Pest Management
Neem (Azadirachta indica A. Juss) is perhaps the most useful traditional medicinal plant in India. Each part of the neem tree has huge insecticidal property and is thus commercially exploitaed. During the last two decades, apart from the chemistry of the neem compounds, considerable progress has been achieved regarding the biological activity and insecticidal applications of neem. It is now considered as a valuable source of unique natural products for botanical insecticides against various pests. This review gives a bird's eye view mainly on the biological activities of some of the neem compounds isolated, insecticidal actions of the neem extracts, applications of neem has an eco friendly botanical insecticide in pest management along with their safety evaluation.
2021
Use of acaricides has become a common practice to control pests all over the world including Saudi Arabia. In spite of killing the targeted pests, such insecticides also effect growth of predatory mites. Present study has been conducted to evaluate the impact of two acaricides, abamectin and hexythiazox, on seven species of predatory mites. Standard solutions of abamectin (8.4% w/v) and hexythiazox (10% w/w) were purchased and prepared for direct spray. Acaricides were tested at three serial concentrations of recommended dose (RD), half of the recommended dose (HRD) and double the recommended dose (DRD). Trials were made on eggs, nymphs and adults of the seven species of predatory mites under laboratory conditions. Effect of the applied acaricides was determined one week after the application. The results of the study revealed that all doses of hexythiazox and abamectin are toxic to the nymphs and adults of all seven species of predatory mites but to the variable extent. Furthermore, it was observed that hexythiazox and abamectin reduced the percentage of egg hatching for all seven species of predatory mites. Hexythiazox was found to be more toxic than abamectin to all seven predatory mites. Higher mortality was recorded at DRD and RD, while minimum mortality was recorded at HRD. Acaricidal effect is less severe on hatching eggs than on immatures and adults of the predatory mites. Species vary in susceptibility to acaricides and in some populations resistance has been observed. Based upon this study, it is recommended that the frequent use of acaricides against phytophagous mites should be avoided and feasibility of biological control programs should be promoted to protect the environment, health of living individuals and the non-target organisms.
2009
Laboratory studies has beel conducted as part ofa prcject aimed at developn-rent ofa neetn-based insecticide for pest management purposes. Data are preselted for permethrin, a pyretluoicl insecticide, and neern (Azadit'achta irdica) products tested agaiust larvae of Diamondback Moth P1ttella xylostella and Helicoverpa arnigera which were collected from several locatlons in West .Iava, Indonesia The results of bioassay showed that the average LC56 values of Plutella rylostella strain of Pangalengan, Garut and Lembang had beel 60-100 fold higher to pennetluin as comparecl with that of tlie nonnal dosage recoulnended, Similariy, the LCso values obtainedfromHelicoverpa amigera collected from Lernbang, Pangalcngan, and Jatinangor straius shorved the sarne trend with LCso values which l1ad been 46-73 fbld as compared with that recomrnended dosage The thct tliat the LCso values of both pli.rtelta rylostella attd, Ilelicot,erpa arnigera were rnuch higher than the recomneuded rates tbr c...