Acetamiprid Treatment Research Articles

Toxicity of Pesticides Applied in European Vineyards on Anagyrus vladimiri and Trichogramma evanescens, Parasitoids of Planococcus ficus and Lobesia botrana.

Risk assessments of chemical pesticides toward natural enemies are crucial for ensuring sustainable grapevine-integrated pest management. In this context, laboratory experiments were conducted to evaluate the toxicity of four insecticides (lambda-cyhalothrin, flupyradifurone, acetamiprid, and cyantraniliprole) and one fungicide (spiroxamine) commonly applied in German (European) vineyards on the pupae and adults of both Anagyrus vladimiri, a parasitoid of the vine mealybug Planococcus ficus, and Trichogramma evanescens, a parasitoid of the European grapevine moth, Lobesia botrana. The tested pesticides did not significantly affect the development of the pupal stage inside mealybug mummies or the emergence of the parasitoid A. vladimiri. The pesticides flupyradifurone, acetamiprid, and spiroxamine resulted in the highest mortality percentages for all emerged A. vladimiri parasitoids at 8 and 10 days after treatment compared with either in lambda-cyhalothrin or cyantraniliprole. However, all pesticides, except the diamide insecticide cyantraniliprole, significantly affected the development of the pupal stage and the emergence of the parasitoid T. evanescens. The percentages of T. evanescens emergence following the application of the fungicide spiroxamine or either lambda-cyhalothrin or flupyradifurone were significantly higher than those observed in the acetamiprid treatment. Regarding direct contact toxicity, the highest percentages (100%) of A. vladimiri adult parasitoid mortality were obtained in the flupyradifurone, acetamiprid, and spiroxamine treatments, while the lowest mortality percentages were observed in lambda-cyhalothrin, cyantraniliprole, and untreated control treatments. According to the IOBC classes of toxicity, flupyradifurone, acetamiprid, and spiroxamine were classified as harmful, while both lambda-cyhalothrin and cyantraniliprole were classified as slightly harmful to A. vladimiri adults. As such, all pesticides had a significant impact on the survival of exposed T. evanescens adults. The highest percentages of adult T. evanescens mortality were obtained in the flupyradifurone, acetamiprid, and spiroxamine treatments, with the fungicide spiroxamine resulting in significantly higher mortality percentages than either flupyradifurone or acetamiprid, while the lowest mortality percentages were found in the lambda-cyhalothrin and cyantraniliprole treatments. Therefore, applying the insecticides acetamiprid and/or flupyradifurone and the fungicide spiroxamine should be avoided when A. vladimiri and/or T. evanescens are naturally present or released in grapes. The insights gained from these two easy-to-rear parasitoid species allow analogous conclusions to be drawn for closely related species in vineyards belonging to either family Encyrtidae or Trichogrammatidae, which are not easy to rear. Interestingly, using the safer insecticides lambda-cyhalothrin and/or cyantraniliprole could be compatible with both parasitoid species, which could be sustainably exploited in either conservation or augmentative biological control in vineyards.

An integrated approach to evaluate acetamiprid-induced oxidative damage to tRNA in human cells based on oxidized nucleotide and tRNA profiling

Acetamiprid is poisonous to mammals due to severe acetamiprid-induced oxidative stress that could cause mitochondrial dysfunctions, lipid and protein oxidation, inflammation, apoptosis, and DNA damage. Evidence has accumulated for the role of oxidative stress in changing structures and functions of transfer RNAs (tRNAs) by inducing tRNA cleavage, reprogramming tRNA modifications and impairing aminoacyl-tRNA synthetase editing sites. However, the impact of acetamiprid-induced oxidative stress on tRNA is still unknown. Here, we investigated the effects of acetamiprid on cell viability, reactive oxygen species (ROS) levels, DNA damage, cellular oxidized nucleotide concentrations, and oxidative damage to tRNA in HepG2 cells and LO2 cells. Acetamiprid can cause the significant increment of ROS and DNA oxidative damage. In this study, an integrated approach was established to simultaneously study the network of oxidized nucleotides and explore the tRNA oxidative damage after acetamiprid exposure. A simple and high-throughput liquid chromatography with tandem mass spectrometry (LC-MS/MS) method coupled with (trimethylsilyl)diazomethane (TMSD) derivatization was successfully developed to quantify 12 cellular oxidized nucleotides that cannot be detected using traditional detection methods because of the huge interferences from naturally abundant nucleotides. Meanwhile, the accumulation rate and the locating sites of 8-oxo-2, 7-dihydro-guanine (8-oxo-G) in tRNA were inspected using the established N-(tert-Butyldimethylsilyl)-N-methyl-trifluoroacetamide (MTBSTFA) labeling-based tRNA profiling method. After acetamiprid treatment, the increment of oxidized nucleoside triphosphates is smaller than that of their corresponding mono- and diphosphates, as well as the dephosphorylated nucleosides, on account of the existence of sanitization enzymes. Several tRNA fragments, CUC[m1A]Gp, CACGp, [Cm]C[m2G]p, and DDGp, are significantly downregulated in acetamiprid-treated HepG2 cells, while only [Cm]C[m2G]p in acetamiprid-treated LO2 cells. According to the profiling results, the significantly changed fragment CUC[m1A]Gp might be caused by the oxidation of guanine (G) to form 8-oxo-G at position 15 in human tRNAphe([Gm]AA), providing more information about the effect of oxidized nucleobases on tRNA’s functions.

Effects of Acetamiprid at Low and Median Lethal Concentrations on the Development and Reproduction of the Soybean Aphid Aphis glycines.

Simple SummaryWe conducted a study on the effects of LC50 and LC30 acetamiprid on the growth and development of the soybean aphid Aphis glycines Matsumura (Hemiptera: Aphididae). We found that exposure to acetamiprid at LC50 significantly extended the mean generation time, adult pre-ovipositional period, and total pre-reproduction period compared to the control, whereas exposure to acetamiprid at LC30 significantly shortened these periods. Acetamiprid at LC50 treatment significantly decreased the growth rate compared with the LC30 treatment. In addition, this study also found that low lethal concentration of acetamiprid could advance the occurrence of a reproductive peak, which could help us understand the major occurrence period of soybean aphids under acetamiprid stress. The present study provides reference data that could facilitate the exploration of the effects of acetamiprid on A. glycines in the field.The soybean aphid Aphis glycines Matsumura (Hemiptera: Aphididae) is a major pest of soybean and poses a serious threat to soybean production. Studies on the effect of acetamiprid on the life table parameters of A. glycines, provide important information for the effective management of this pest. We found that exposure to acetamiprid at LC50 significantly extended the mean generation time, adult pre-reproductive period, and total pre-reproduction period compared with the control, whereas exposure to acetamiprid at LC30 significantly shortened these periods. Exposure to acetamiprid at both LC30 and LC50 significantly decreased the fecundity of the female adult, net reproductive rate, intrinsic rate of increase, and finite rate of increase compared with the control. The probability of attaining the adult stage was 0.51, 0.38, and 0.86 for a newly born nymph from the LC30 acetamiprid treatment group, LC50 acetamiprid treatment group, and control group, respectively. Acetamiprid at both LC50 and LC30 exerted stress effects on A. glycines, with the LC50 treatment significantly decreased the growth rate compared with the LC30 treatment. The present study provides reference data that could facilitate the exploration of the effects of acetamiprid on A. glycines in the field.

Determination of the Maximum Appearance Period of Capnodis tendebrionis in Al-Sweida-Syria Governorate and Testing the Efficacy of Some Pesticides on the Pest Adults

Bufaur, M., S. Al-Gkhami, R. Bohamdan, W. Ghanem and M. Dawara. 2021. Determination of the Maximum Appearance Period of Capnodis tendebrionisin Al-Sweida-Syria Governorate and Testing the Efficacy of Some Pesticides on the Pest Adults. Arab Journal of Plant Protection, 39(4): 268-272. https://doi.org/10.22268/AJPP-39.4.268272 A weekly adults collection of Capnodis tendebrionis L. (Buprestidae; Coleoptera) was conducted for two seasons (2018, 2019) to determine the maximum insect adults appearance period. Early adult appearance was recorded in the first year in warm-dry months as compared to the second year in cold-wet months. Maximum insect adults appearance was recorded at the end of April during the first season and at the end of May in the second season. A field experiment was carried out to test the efficacy of some pesticides on controlling pest adults: Deltamethrin, 100g/l, Chlorpyriphos-ethyl 48% and Acetamiprid 20% as a foliar spray, and Deltamethrin 0.25% as dusting powder around the stem, in addition to the control. Results obtained showed that Chlorpyriphos-ethyl and the two Deltamethrin treatments were the best on adults and with significant differences compared with Acetamiprid treatment following the first and the second week after spraying in 2018, and the Deltamethrin as dusting powder and Chlorpyriphos-ethyl treatments were the best and with significant differences compared to other treatments were observed. Using Deltamethrin as dusting powder around the stem was highly efficient during three weeks after spraying as compared with other treatments in the two years. Keywords: Capnodis tendebrionis L., Maximum adult appearance period, Deltamethrin, Chlorpyriphos- ethyl and Acetamiprid

Imbalance of intestinal microbial homeostasis caused by acetamiprid is detrimental to resistance to pathogenic bacteria in Bombyx mori

The neonicotinoid insecticide acetamiprid is widely applied for pest control in agriculture production, and its exposure often results in adverse effects on a non-target insect, Bombyx mori. However, only few studies have investigated the effects of exposure to sublethal doses of neonicotinoid insecticides on gut microbiota and susceptibility to pathogenic bacteria. In this study, we aimed to explore the possible mechanisms underlying the acetamiprid-induced compositional changes in gut microbiota of silkworm and reduced host resistance against detrimental microbes. This study indicated that sublethal dose of acetamiprid activated the dual oxidase-reactive oxygen species (Duox-ROS) system and induced ROS accumulation, leading to dysregulation of intestinal immune signaling pathways. The evenness and structure of bacterial community were altered. Moreover, after 96 h of exposure to sublethal dose of acetamiprid, several bacteria, such as Pseudomonas sp (Biotype A, DOP-1a, XW34) and Staphylococcus sp (RCB1054, RCB314, X302), invaded the silkworm hemolymph. The survival rate and bodyweight of the acetamiprid treated silkworm larvae inoculated with Enterobacter cloacae (E. cloacae) were significantly lower than the acetamiprid treatment group, suggesting that acetamiprid reduced silkworm resistance against pathogens. These findings indicated that acetamiprid disturbed gut microbial homeostasis of Bombyx mori, resulting in changes in gut microbial community and susceptibility to detrimental microbes.

A comparative study on the effects of selected pesticides on hemato-biochemistry and tissue histology of freshwater fish Cirrhinus mrigala (Hamilton, 1822).

The aim of the present study was to investigate the comparative effects of pesticides Chlorfenapyr, Dimethoate and Acetamiprid on the health of Cirrhinus mrigala under long term exposure. Eighty C. mrigala were divided in four equal groups; one control and three treated groups. The blood was collected from both control and treated groups at intervals of 10th, 20th and 30th days for hemato-biochemistry and histopathological alterations. The result indicates significant difference (P < 0.05) in RBCs, Hb, PCV and MCHC whereas elevation in WBCs and Platelets counts were recorded. In 10th day sampling, MCV value of Dimethoate and Acetamiprid treatment had no difference in comparison with the control group, however it is significantly increased (P < 0.05) in rest of sampling. The MCH value of exposed fish showed significant increased (P < 0.05) after 20th and 30th days for Chlorfenapyr and after 30th days for Acetamiprid exposure while insignificantly increased for rest of sampling. It was also found that these pesticides significantly decrease (p < 0.05) the T3 and T4 levels while increase in the TSH, cortical, ALP, AST, ALT and LDH levels in the serum of the treated fishes in contrast to control group. Similarly, histopathological analysis of gills and liver showed significant alterations in all the treated groups. Toxicity trends of these pesticides was ranked as Chlorfenapyr > Acetamiprid > Dimethoate. It is concluded that indiscriminate use of such pesticides poses a noxious threat to non-target organisms, harm the ecosystems and jeopardizes human health.

The neonicotinoids acetamiprid and imidacloprid impair neurogenesis and alter the microglial profile in the hippocampal dentate gyrus of mouse neonates.

Acetamiprid (ACE) and imidacloprid (IMI) are widely used neonicotinoid pesticides. They bind selectively to insect nicotinic acetylcholine receptors (nAChRs) and are considered non-hazardous to mammals. Few studies have assessed the activation of vertebrate nAChRs and the neurodevelopmental toxicity following in utero or neonatal exposure to neonicotinoids; therefore, we evaluated the effects of ACE or IMI exposure on neurogenesis and microglial profiles in the developing hippocampal dentate gyrus (DG) of mouse neonates. Mice were exposed to ACE, IMI (both 5mg/kg/day) or nicotine (0.5mg/kg/day) from postnatal day (P)12 to P26 by oral gavage. On P27, brains were removed, and neurogenesis and microglial activation in the hippocampal DG were examined via immunohistochemistry. A reduction in neurogenesis in the hippocampal DG of neonates following ACE, IMI and nicotine treatment was found. Additionally, neonicotinoid-exposed newborns showed an increase in the number of amoeboid-type and activated M1-type microglia. These results suggest that exposure to ACE and IMI impairs neurogenesis and alters microglial profiles in the developing hippocampal DG following oral dosing in an early postnatal period. A better understanding of the potential effects of these pesticides on human infant health is an important goal of our research.

Attenuating effects of Mangifera indica leaves ethanolic extract against acetamiprid induced reproductive toxicity in male guinea pigs.

Acetamiprid (ACP) belonging to the neonicotinoid family used against wide array of pests in agriculture and domestic purposes. In this study, we evaluated the attenuating effects of ethanolic extract of Mangifera indica leaves (EEMI) in averting reproductive toxicity caused by ACP in male guinea pigs. Thirty male guinea pigs were randomly assigned to five treatment groups (n = 6). Group 1 (T0) received distilled water orally; group 2 (T0-) was given 80 mg kg-1 of ACP and groups 3, 4 and 5 were treated, respectively, with EEMI at doses of 50, 100 and 200 mg kg-1 plus ACP. After 90 days, the reaction time, sexual organ weights, sperm count, motility and anomalies, spermatozoa with entire plasma membrane, testicular histology, serum testosterone concentration, testicular malondialdehyde (MDA) level, reduced glutathione (GSH) concentration, testicular superoxide dismutase (SOD) and catalase (CAT) activities were assessed. Co-administration of EEMI significantly reduced the reaction time, sperm anomalies and testicular MDA, SOD and CAT levels compared to the T0- group. Co-treatment of EEMI significantly alleviated sperm count and motility, percentage of spermatozoa with the normal plasma membrane, serum testosterone concentration, accessory sex gland weights, and testicular GSH concentrations. The ACP treatment induced cell membrane degradation in the testis and this effect was prevented with the addition of EEMI. In conclusion, ACP negatively affected the animal reproductive function and induced oxidative stress. The addition of EEMI alleviated the toxic effects of ACP on the reproductive function of male guinea pigs.

Assessment of acetamiprid-induced genotoxic effects in bone marrow cells of Swiss albino male mice

Acetamiprid (ACE), a neonicotinoid insecticide, is widely used in agriculture either alone or in combination with other insecticides. A combined approach employing micronucleus test (MNT) and chromosomal aberrations (CA) assay was utilized to assess the genotoxic effects of ACE in bone marrow of Swiss albino male mice. Acetamiprid was administered i.p. daily at 4.6 and 2.3 mg/kg/day along with 3% gum acacia as negative control for 60 and 90 days and cyclophosphamide (50 mg/kg b.wt.) as positive control. ACE treatment resulted in a dose-dependent increase in the frequencies of micronuclei per cell and chromosomal aberrations in bone marrow cells. The increased micronuclei formation in total erythrocyte cells (immature PCEs and mature NCEs) was observed only at higher dose level (4.6 mg/kg b.wt.) administered for 90 days. The test also indicated the cytotoxic effect of higher dose level of pesticide by PCE/NCE ratio. The number of chromosomal aberrations were increased in the pesticide treated group compared to the negative control group, although significant increase was observed only in the group exposed to higher dose level of pesticide for both 60 and 90 days. Thus, daily exposure of ACE at a dose level of 4.6 mg/kg body weight for 60 and 90 days caused genotoxic and cytotoxic effects on the somatic cells of Swiss albino male mice.

Neuroprotective effects of curcumin against acetamiprid-induced neurotoxicity and oxidative stress in the developing male rat cerebellum: biochemical, histological, and behavioral changes

Curcumin is a molecule found in turmeric root that has anti-inflammatory, antioxidant, and anti-tumor properties and has been widely used as both an herbal drug and a food additive to treat or prevent neurodegenerative diseases. This study aimed to investigate the effect of curcumin on neurobehavioral and neuropathological alterations induced by acetamiprid on male rats. Three groups of ten male Wistar rats each were used for the study: the first was a control group (CTR) that did not consume acetamiprid (ACE); the second was an experimental group (ACE) that consumed 40mg/kg body weight/day of acetamiprid; and the third group (CUR) received curcumin (100mg/kg) and acetamiprid (40mg/kg) in combination. Neurobehavioral evaluations including inclined plane performance and forepaw grip time were studied. Treatment with CUR significantly prevented ACE-treated rats from impairments in the performance of neurobehavioral tests, indicating the presence of deficits on sensorimotor and neuromuscular responses. In addition, Curcumin administration protects rats against acetamiprid-induced cerebellum toxicity such as increase in AChE and BChE activities, decrease on cells viability, oxidative stress, and an increase of intracellular calcium. Taken together, these results demonstrate for the first time that ACE treatment substantially impairs the survival of primary neuronal cells through the induction of necrosis concomitantly with the generation of an oxidative stress. Additionally, curcumin reduced histopathological changes caused by ACE.

Acetamiprid Accumulates in Different Amounts in Murine Brain Regions.

Neonicotinoids such as acetamiprid (ACE) belong to a new and widely used single class of pesticides. Neonicotinoids mimic the chemical structure of nicotine and share agonist activity with the nicotine acetylcholine receptor (nAchR). Neonicotinoids are widely considered to be safe in humans; however, they have recently been implicated in a number of human health disorders. A wide range of musculoskeletal and neuromuscular disorders associated with high doses of neonicotinoids administered to animals have also been reported. Consequently, we used a mouse model to investigate the response of the central nervous system to ACE treatment. Our results show that exposure to ACE-containing water for three or seven days (decuple and centuple of no observable adverse effect level (NOAEL)/day) caused a decrease in body weight in 10-week old A/JJmsSlc (A/J) mice. However, the treatments did not affect brain histology or expression of CD34. ACE concentrations were significantly higher in the midbrain of ACE-treated mice than that of the normal and vehicle groups. Expression levels of α7, α4, and β2 nAChRs were found to be low in the olfactory bulb and midbrain of normal mice. Furthermore, in the experimental group (centuple ACE-containing water for seven days), β2 nAChR expression decreased in many brain regions. Information regarding the amount of accumulated ACE and expression levels of the acetylcholine receptor in each region of the brain is important for understanding any clinical symptoms that may be associated with ACE exposure.

Incorporation of Biorational Insecticides with Neonicotinoids to Combat Resurgence ofTetranychus urticae(Prostigmata: Tetranychidae) on Rose

Rose plants were treated with 2 neonicotinoids (imidacloprid and acetamiprid), 3 biorationals (spinosad, emamectin benzoate, and Beauveria bassiana [Bals.-Criv.] Vuill. [Hypocreales: Cordycipitaceae]), and combinations of neonicotinoids and biorationals to control two-spotted spider mites (Tetranychus urticae Koch; Prostigmata: Tetranychidae) on rose. Toxicity bioassays revealed that imidacloprid drench, imidacloprid foliar applications, and acetamiprid treatments significantly increased spider mite numbers, whereas treatments with spinosad or with emamectin either alone or in combinations with imidacloprid and acetamiprid resulted in significantly fewer spider mites compared with the untreated control. Beauveria bassiana was least effective in controlling the spider mite population. The fecundity experiment indicated that the imidacloprid drench and foliar treatments significantly increased the number of mite eggs produced during observation days up to 9 d after treatment (DAT) for the drench treatment and up to 7 DAT for the foliar treatments. Acetamiprid did not induce any significant changes in spider mite egg production. Spinosad, emamectin, and B. bassiana alone or in combinations induced significant reductions in egg numbers compared with the control at almost all observation days. Both preference and non-preference tests indicated that the drench and the foliar applications with imidacloprid resulted in significantly more spider mites on treated leaf discs at 5 and 7 DAT than on untreated leaves. In conclusion, spinosad and emamectin in combinations with the neonicotinoids can be incorporated into the integrated pest management of the two-spotted spider mite on roses.

Influence of short-time imidacloprid and acetamiprid application on soil microbial metabolic activity and enzymatic activity.

The influence of two neonicotinoids, i.e., imidacloprid (IMI) and acetamiprid (ACE), on soil microbial activities was investigated in a short period of time using a combination of the microcalorimetric approach and enzyme tests. Thermodynamic parameters such as Q T (J g(-1) soil), ∆H met (kJ mol(-1)), J Q/S (J g(-1) h(-1)), k (h(-1)), and soil enzymatic activities, dehydrogenase, phosphomonoesterase, arginine deaminase, and urease, were used to evaluate whole metabolic activity changes and acute toxicity following IMI and ACE treatment. Various profiles of thermogenic curves reflect different soil microbial activities. The microbial growth rate constant k, total heat evolution Q T (expect for IMI), and inhibitory ratio I show linear relationship with the doses of IMI and ACE. Q T for IMI increases at 0.0-20 μg g(-1) and then decreases at 20-80 μg g(-1), possibly attributing to the presence of tolerant microorganisms. The 50 % inhibitory ratios (IC50) of IMI and ACE are 95.7 and 77.2 μg g(-1), respectively. ACE displays slightly higher toxicity than IMI. Plots of k and Q T against microbial biomass-C indicate that the k and Q T are growth yield-dependent. IMI and ACE show 29.6; 40.4 and 23.0; and 23.3, 21.7, and 30.5 % inhibition of dehydrogenase, phosphomonoesterase, and urease activity, respectively. By contrast, the arginine deaminase activity is enhanced by 15.2 and 13.2 % with IMI and ACE, respectively. The parametric indices selected give a quantitative dose-response relationship of both insecticides and indicate that ACE is more toxic than IMI due to their difference in molecular structures.

Sublethal effect of avermectin and acetamiprid on the mortality of different life stages of Brontispa longissima (Gestro) (Coleoptera: Hispidae) and its larvae parasitoid Asecodes hispinarum Bouček (Hymenoptera: Eulophidae)

The beneficial parasitoid Asecodes hispinarum Bouček plays an important role in integrated pest management (IPM) of the coconut leaf beetle, Brontispa longissima (Gestro), in China. A. hispinarum females parasitize 3rd to 4th instars B. longissima larvae. Hatched parasitoid larvae develop within the host, and parasitoid adults emerge through holes that they chew through the cuticle of the host. Although chemicals serve as the main short term control agents, the compatibility of biological and chemical control has never been investigated for this system. This study examined the responses of immature and adult B. longissima and its larval parasitoid A. hispinarum to avermectin and acetamiprid. Avermectin caused complete mortality of 2nd to 4th instar larvae, and of adults of B. longissima at 10, 15 and 2 d after treatment, respectively. However, 26.7% of the 2nd instar larvae, 55.3% of the 4th instar larvae, and 74%, of adult B. longissima were still alive 40 d after acetamiprid application. Following avermectin exposure, 17.5%, 9.2% and 23% of mummified B. longissima larvae contained viable adult parasitoids for the parasitoid egg, larva and pupa treatments, respectively, and the numbers of dead parasitoids per mummy were 3.3, 7.2 and 13.3 for the egg, larva and adult treatments, respectively. However, for acetamiprid treatment, 70–75.9% of mummified B. longissima larvae contained viable adult parasitoids in all three stage treatments, and the number of dead parasitoids per mummy was 2.8, 2 and 3.4 in egg, larva and adult treatments, respectively. This study showed that a sublethal dose of avermectin is more toxic than acetamiprid to B. longissima and A. hispinarum. Therefore, direct contact of the parasitoid with avermectin should be avoided when this insecticide is used to control B. longissima.

Relative Repellency and Lethality of the Neonicotinoids Thiamethoxam and Acetamiprid and an Acetamiprid/Bifenthrin Combination to &lt;I&gt;Reticulitermes flavipes&lt;/I&gt; Termites

Field-collected Reticulitermes flavipes (Kollar) termites were placed in bioassay tubes containing soil treated with one of three termiticides: thiamethoxam, acetamiprid, or a combination of acetamiprid + bifenthrin. In the bioassay tubes, treated soil was placed in a layer centered within untreated sand between two 1.5-cm agar plugs. All termiticides were tested at concentrations of 0.1, 1, 10, and 100 ppm with narrow (1 mm), medium (5 mm), and broad (50 mm) thicknesses of treated soil. Soil penetration and termite mortality were measured after 7 d, and repellency was assessed. Thiamethoxam treatments allowed the greatest soil penetration, whereas acetamiprid + bifenthrin treatments were the most inhibitory to soil penetration. Thiamethoxam treatments also caused consistently greater termite mortality than acetamiprid treatments. These data indicated that acetamiprid prevented soil penetration by termites more than thiamethoxam, although both were less repellent compared with bifenthrin alone, which causes little termite mortality at the tested doses. When there was direct contact of treated soil with the agar plugs in broad treatments, the combination of acetamiprid + bifenthrin was more toxic to R. flavipes termites than either acetamiprid or thiamethoxam alone. The combination acetamiprid + bifenthrin termiticide may be effective in keeping termites away from the treated soil, because of the combined effects of acetamiprid and bifenthrin.

Nitrate reductase, arginine deaminase, urease and dehydrogenase activities in natural soil (ridges with forest) and in cotton soil after acetamiprid treatments

Soil enzymes are indicators of microbial activities in soil and are often considered as an indicator of soil health and fertility. They are very sensitive to the agricultural practices, pH of the soil, nutrients, inhibitors and weather conditions. To understand the effect of an insecticide, acetamiprid (IUPAC Name: (E)- N1-[(6-chloro-3-pyridyl) methyl]- N2-cyano- N1-methyl acetamidine) on different soil enzyme activities, the experiments were conducted for three consecutive years (2003–2005) at control and cotton experimental fields of Indian Agricultural Research Institute (IARI) and natural area (ridges with forest) in Delhi. The combined results for all three years were presented here to understand the impact of acetamiprid on soil enzyme activities. Acetamiprid was applied three times in one crop season after 41, 48 and 73 days of sowing, to control the pest. Soil of treated fields was analyzed for insecticide residues immediately after first insecticide treatment and thereafter at definite period. The residues of acetamiprid in experimental soil was varied from 0.30 ± 0.13 to 22.67 ± 0.2 μg g −1 d.wt. soil, during the crop period of 2003. The insecticide residues for 2004 ranged between 0.59 ± 0.38 and 13.42 ± 0.71 μg g −1 d.wt. soil and for 2005 it ranged between 0.48 ± 0.22 and 19.81 ± 0.33 μg g −1 d.wt. soil. An average half life of acetamiprid in our treated field was 11.2 ± 1.7 days for all three years. Similarly, the soil from natural area and control were also tested for insecticide residues. No detectable insecticide residues had been found. Soil from three localities i.e. natural, control and experimental fields were tested for different enzyme activities. Nitrate reductase, arginine deaminase, urease and dehydrogenase activities were high in natural soil in comparison to control soil and insecticide treated soil in all three experimental years. At the same time, nitrate reductase activity was all time low in acetamiprid treated soil. Acetamiprid had inhibitory effects on nitrate reductase, arginine deaminase and urease activities. After first treatment (43 days after crop sowing), nitrate reductase (41%), arginine deaminase (22%) and urease (35%) activities were declined. Dehydrogenase activity increased to 22% after first insecticide application. Enzyme activities were recovered at the end of each crop season. Therefore, it can be attributed that agricultural practices, weather conditions and use of acetamiprid might be responsible for the different level of enzyme activities in soil.

Role of neonicotinyl insecticides in Washington apple integrated pest management. Part II. Nontarget effects on integrated mite control

The effect of neonicotinyl insecticides on integrated mite control in Washington apple was examined from 0 In a series of 20 field trials (54 treatments) designed primarily to look at efficacy against the codling moth, Cydia pomonella, nearly half of the treatments using four or more applications of acetamiprid had peak mite densities exceeding the economic threshold of 5 mites per leaf. Overall, acetamiprid treatments had 4.6-fold higher mite densities than the standard organophosphate insecticide treatment. Of the treatments with high mite populations, Panonychus ulmi, the European red mite, and Tetranychus urticae, the twospotted spider mite, were the dominant species in roughly equal numbers of cases. Only 11.1% of the thiacloprid treatments exceeded 5 mites per leaf; these experimental treatments included eight applications, whereas the current label restricts the number of applications at the rate for C. pomonella to two applications. One out of six clothianidin treatments caused a significantly higher mite density than the standard treatment; however, this material appeared to suppress predatory mites. Neonicotinyl insecticides did not eliminate predatory mites, but they inhibited their ability to respond normally to increasing prey populations. In field trials designed specifically to examine mite population densities where neonicotinyl insecticides were used, significantly higher levels of tetranychid mites occurred in one or more acetamiprid treatments (one, two or four applications) in five out of six trials. In the sixth trial (in a commercial orchard), only two acetamiprid applications were made, and mite populations were low in all treatments. While elevated mite densities were more likely to occur with four applications, in one case it occurred following a single application. The predominant tetranychid mite species (either P. ulmi or T. urticae) varied from trial to trial; however, there was no apparent bias regarding stimulation of the two species. Horticultural mineral oil was used with acetamiprid in some trials in an attempt to mitigate mite outbreaks. However, the addition of oil did not counteract the tendency of acetamiprid to increase tetranychid mite populations, and in one trial, had a negative effect on predatory mite densities. Seasonal tetranychid mite density was positively related to the total grams AI (or number of applications) of acetamiprid, thus reducing the number of applications per season should lower the probability of mite outbreaks.AI active ingredient CMD cumulative mite days

Role of neonicotinyl insecticides in Washington apple integrated pest management. Part II. Nontarget effects on integrated mite control

The effect of neonicotinyl insecticides on integrated mite control in Washington apple was examined from 0 In a series of 20 field trials (54 treatments) designed primarily to look at efficacy against the codling moth, Cydia pomonella, nearly half of the treatments using four or more applications of acetamiprid had peak mite densities exceeding the economic threshold of 5 mites per leaf. Overall, acetamiprid treatments had 4.6-fold higher mite densities than the standard organophosphate insecticide treatment. Of the treatments with high mite populations, Panonychus ulmi, the European red mite, and Tetranychus urticae, the twospotted spider mite, were the dominant species in roughly equal numbers of cases. Only 11.1% of the thiacloprid treatments exceeded 5 mites per leaf; these experimental treatments included eight applications, whereas the current label restricts the number of applications at the rate for C. pomonella to two applications. One out of six clothianidin treatments caused a significantly higher mite density than the standard treatment; however, this material appeared to suppress predatory mites. Neonicotinyl insecticides did not eliminate predatory mites, but they inhibited their ability to respond normally to increasing prey populations. In field trials designed specifically to examine mite population densities where neonicotinyl insecticides were used, significantly higher levels of tetranychid mites occurred in one or more acetamiprid treatments (one, two or four applications) in five out of six trials. In the sixth trial (in a commercial orchard), only two acetamiprid applications were made, and mite populations were low in all treatments. While elevated mite densities were more likely to occur with four applications, in one case it occurred following a single application. The predominant tetranychid mite species (either P. ulmi or T. urticae) varied from trial to trial; however, there was no apparent bias regarding stimulation of the two species. Horticultural mineral oil was used with acetamiprid in some trials in an attempt to mitigate mite outbreaks. However, the addition of oil did not counteract the tendency of acetamiprid to increase tetranychid mite populations, and in one trial, had a negative effect on predatory mite densities. Seasonal tetranychid mite density was positively related to the total grams AI (or number of applications) of acetamiprid, thus reducing the number of applications per season should lower the probability of mite outbreaks.

Laboratory bioassays and field evaluation of insecticides for the control of Anthonomus rubi, Lygus rugulipennis and Chaetosiphon fragaefolii, and effects on beneficial species, in UK strawberry production

Abamectin, Beauveria bassiana, buprofezin, pymetrozine, tebufenpyrad, acetamiprid and the coded product 60145 were tested in laboratory bioassays to determine their effects on the strawberry pests Anthonomus rubi, Lygus rugulipennis and Chaetosiphon fragaefolii and on the predatory species Phytoseiulus persimilis and Chrysoperla carnea. Abamectin, acetamiprid, tebufenpyrad and 60145 were the most effective insecticides against the pests. These four compounds all had some effect on P. persimilis, but acetamiprid was the least toxic (63% mortality after 48 h). Abamectin, tebufenpyrad and 60145 had no detectable effect on C. carnea larvae, whereas acetamiprid caused 38% mortality after 72 h. In field experiments where acetamiprid, 60145 and abamectin were tested against C. fragaefolii, acetamiprid was very effective at reducing numbers of the aphid. Naturally occurring beneficial anthocorid species were reduced in number but not eliminated in the acetamiprid treatment. In field tests acetamiprid, abamectin and thiacloprid were less effective against L. rugulipennis than the industry standard chlorpyrifos. Reductions were small but statistically significant in the acetamiprid and thiacloprid treatments. Fruit damage was also reduced in these treatments. There was no detectable effect of these insecticides on naturally occurring beneficial species.

Compatibility of entomopathogenic fungi with neonicotinoid insecticides

The in vitro fungitoxic effect of the neonicotinoid insecticides acetamiprid (Saurus 200 SP), imidacloprid (Confidor 700 WDGr) and thiamethoxam (Actara 250 WG) in three concentrations (AR= average field recommendation; 0.7 AR and 1.3 AR) to the entomopathogenic fungi Beauveria bassiana, Metarhizium anisopliae and Paecilomyces sp. was studied. The effect of the insecticides on conidia germination, vegetative growth and conidiogenesis was compared. The insecticides had no effect on conidia germination, except under the highest concentration (1.3 AR) of acetamiprid, in which significant inhibition of M. anisopliae occurred. Vegetative growth of B. bassiana and M. anisopliae was significantly inhibited only by the three concentrations of acetamiprid treatment. Thiamethoxam treatment, in the AR and 1.3 AR concentrations, was significantly lower for B. bassiana vegetative growth. Paecilomyces sp. vegetative growth was higher than the control in the following treatments: 0.7 AR and AR of acetamiprid; all concentrations of imidacloprid; and in the two smallest concentrations, 0.7 AR and AR, of thiamethoxam. Conidia production was significantly smaller for Paecilomyces sp. and M. anisopliae, in the highest concentration (1.3 AR) of acetamiprid treatment and, for Paecilomyces sp., in the highest concentration (1.3 AR) of imidacloprid. Thiamethoxam significantly inhibited M. anisopliae conidia production, only in the smallest concentration (0.7 AR).Significant increase in the conidia production of Paecilomyces sp. fungus was observed in the following treatments: two concentrations, 0.7 AR and AR of acetamiprid; and in the two highest concentrations, AR and 1.3 AR, of thiamethoxam treatments. The use of insecticides, in the recommended formulations and other concentrations tested, in most cases, had no negative effect on conidia germination, conidia production and vegetative growth of B. bassiana, M. anisopliae and Paecilomyces sp. Consequently, these products, in the formulations and concentrations tested, may be used in IPM programs in which the entomopathogens are important pest regulators.