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Alfred Elbert - One of the best experts on this subject based on the ideXlab platform.
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european monitoring of resistance to insecticides in myzus persicae and aphis gossypii hemiptera aphididae with special reference to imidacloprid
Bulletin of Entomological Research, 2003Co-Authors: Ralf Nauen, Alfred ElbertAbstract:The susceptibility to several insecticides of 16 and 8 strains of Myzus persicae Sulzer and Aphis gossypii Glover, respectively, received from different European countries in 2001 was investigated. Most of the strains were derived from places known for their aphid resistance problems to conventional insecticides before imidacloprid was introduced. In many regions and agronomic cropping systems imidacloprid has been an essential part of aphid control strategies for a decade, and therefore the susceptibility of aphid populations to imidacloprid using FAO-dip tests and diagnostic concentrations in a leaf-dip bioassay was checked. Additional insecticides tested were cyfluthrin (chemical class: pyrethroid), pirimicarb (carbamate), methamidophos and Oxydemeton-Methyl (organophosphates). Diagnostic concentrations (LC 99 -values of reference strains) for each insecticide were established by dose response analysis using a new leaf-disc dip bioassay format in 6-well tissue culture plates. Virtually no resistance to imidacloprid in any of the field-derived populations of M. persicae and A. gossypii was detected. In contrast, strong resistance was found to pirimicarb and Oxydemeton-Methyl, and to a lesser extent also to cyfluthrin. Two strains of A. gossypii exhibited reduced susceptibility to imidacloprid when tested directly after collection. However, after maintaining them for six weeks in the laboratory, the aphids were as susceptible as the reference strain. The diagnostic concentration of methamidophos did not reveal any resistance in M. persicae , but did so in four strains of A. gossypii .
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Aphicidal activity of imidacloprid against a tobacco feeding strain of Myzus persicae (Homoptera: Aphididae) from Japan closely related to Myzus nicotianae and highly resistant to carbamates and organophosphates
Bulletin of Entomological Research, 1996Co-Authors: Ralf Nauen, Jürgen Strobel, Klaus Tietjen, Yuichi Otsu, Christoph Erdelen, Alfred ElbertAbstract:We investigated the resistance potential of a red-coloured Japanese strain (JR) of a tobacco feeding form of Myzus persicae (Sulzer) of the M. persicae species complex closely related to the tobacco aphid Myzus nicotianae Blackman. Bioassays were performed with a range of insecticides, imidacloprid, nicotine and cartap, thought to act on nicotinic acetylcholine receptors in vivo , as well as with two conventional insecticides, pirimicarb and Oxydemeton-Methyl, acting on acetylchol-inesterase (AChE). Compared to a susceptible strain, JR showed high resistance to pirimicarb and Oxydemeton-Methyl, but was far less resistant to nicotine, cartap and imidacloprid. Imidacloprid was, among the insecticides tested, the most active compound in contact and ingestion bioassays. Compared to the susceptible strain, JR showed four-to seven-fold resistance to imidacloprid depending on the type of bioassay. Resistance factors for other insecticides tested in an oral ingestion bioassay were: cartap five-fold, nicotine nine-fold, Oxydemeton-Methyl 107-fold and pirimicarb > 385-fold. JR showed high carboxylesterase activity. Polyacrylamide gel electrophoresis indicated esterase FE4 as the major carboxylesterase. As for most M. persicae strains and some Greek strains of M. nicotianae , JR was monomorphic for glutamate oxalacetate transaminase. Studies with pirimicarb showed a marked insensitivity of AChE to inhibition by this chemical, whilst such insensitivity could not be detected with the organophosphate insecticide Oxydemeton-Methyl. Receptor binding assays with [ 3 H]-imidacloprid in aphid homogenates revealed I 50 -values of 0.4 to 0.8 nM and no statistical difference between the JR and susceptible strain.
Ralf Nauen - One of the best experts on this subject based on the ideXlab platform.
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european monitoring of resistance to insecticides in myzus persicae and aphis gossypii hemiptera aphididae with special reference to imidacloprid
Bulletin of Entomological Research, 2003Co-Authors: Ralf Nauen, Alfred ElbertAbstract:The susceptibility to several insecticides of 16 and 8 strains of Myzus persicae Sulzer and Aphis gossypii Glover, respectively, received from different European countries in 2001 was investigated. Most of the strains were derived from places known for their aphid resistance problems to conventional insecticides before imidacloprid was introduced. In many regions and agronomic cropping systems imidacloprid has been an essential part of aphid control strategies for a decade, and therefore the susceptibility of aphid populations to imidacloprid using FAO-dip tests and diagnostic concentrations in a leaf-dip bioassay was checked. Additional insecticides tested were cyfluthrin (chemical class: pyrethroid), pirimicarb (carbamate), methamidophos and Oxydemeton-Methyl (organophosphates). Diagnostic concentrations (LC 99 -values of reference strains) for each insecticide were established by dose response analysis using a new leaf-disc dip bioassay format in 6-well tissue culture plates. Virtually no resistance to imidacloprid in any of the field-derived populations of M. persicae and A. gossypii was detected. In contrast, strong resistance was found to pirimicarb and Oxydemeton-Methyl, and to a lesser extent also to cyfluthrin. Two strains of A. gossypii exhibited reduced susceptibility to imidacloprid when tested directly after collection. However, after maintaining them for six weeks in the laboratory, the aphids were as susceptible as the reference strain. The diagnostic concentration of methamidophos did not reveal any resistance in M. persicae , but did so in four strains of A. gossypii .
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Aphicidal activity of imidacloprid against a tobacco feeding strain of Myzus persicae (Homoptera: Aphididae) from Japan closely related to Myzus nicotianae and highly resistant to carbamates and organophosphates
Bulletin of Entomological Research, 1996Co-Authors: Ralf Nauen, Jürgen Strobel, Klaus Tietjen, Yuichi Otsu, Christoph Erdelen, Alfred ElbertAbstract:We investigated the resistance potential of a red-coloured Japanese strain (JR) of a tobacco feeding form of Myzus persicae (Sulzer) of the M. persicae species complex closely related to the tobacco aphid Myzus nicotianae Blackman. Bioassays were performed with a range of insecticides, imidacloprid, nicotine and cartap, thought to act on nicotinic acetylcholine receptors in vivo , as well as with two conventional insecticides, pirimicarb and Oxydemeton-Methyl, acting on acetylchol-inesterase (AChE). Compared to a susceptible strain, JR showed high resistance to pirimicarb and Oxydemeton-Methyl, but was far less resistant to nicotine, cartap and imidacloprid. Imidacloprid was, among the insecticides tested, the most active compound in contact and ingestion bioassays. Compared to the susceptible strain, JR showed four-to seven-fold resistance to imidacloprid depending on the type of bioassay. Resistance factors for other insecticides tested in an oral ingestion bioassay were: cartap five-fold, nicotine nine-fold, Oxydemeton-Methyl 107-fold and pirimicarb > 385-fold. JR showed high carboxylesterase activity. Polyacrylamide gel electrophoresis indicated esterase FE4 as the major carboxylesterase. As for most M. persicae strains and some Greek strains of M. nicotianae , JR was monomorphic for glutamate oxalacetate transaminase. Studies with pirimicarb showed a marked insensitivity of AChE to inhibition by this chemical, whilst such insensitivity could not be detected with the organophosphate insecticide Oxydemeton-Methyl. Receptor binding assays with [ 3 H]-imidacloprid in aphid homogenates revealed I 50 -values of 0.4 to 0.8 nM and no statistical difference between the JR and susceptible strain.
M S Dhooria - One of the best experts on this subject based on the ideXlab platform.
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Screening of rose (Rosa species) varieties against two-spotted spider mite (Tetranychus urticae) (Acari: Tetranychidae) and its control*
Indian Journal of Agricultural Sciences, 2006Co-Authors: Paramjit Kaur, M S Dhooria, Manmeet Brar BhullarAbstract:An experiment was conducted during 2004 to study susceptibility of 7 rose (Rosa spp.) varieties viz 'Eiffle Tower') 'Gold Tops', 'Kiss ofFire', 'Queen Elizabeth', 'Rakatgandha', 'Sea Pearl' and 'Super Star', to the two-spotted spider mite (Tetranychus urticae Koch) through oviposition response, feeding preference and damage caused by mite on them. Variety 'Sea Pearl' was the least preferred by mite and 'Gold Tops' the most. Five pesticides, viz dicofol, ethion, oxydemeton methyl, propargite, and wettable sulphur, were tested for their effectiveness against eggs of the two-spotted spider mite under laboratory conditions at 27 ± l°e. Dicofol (0.025%) and propargite (0.05%) were found the most effective pesticides as ovicides.
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Relative efficacy of different pesticides against red spider mite, Tetranychus cinnabarinus (Boisd.) (Acari: Tetranychidae)
Journal of research, 2004Co-Authors: Kamal Deep, M S DhooriaAbstract:The relative efficacy of eight pesticides namely diafenthiuron, dicofol, dimethoate, ethion, monocrotophos, oxydemeton methyl, propargite and sulphur studied against different developmental stages of red spider mite, Tetranychus cinnabarinus (Boisd.) through bioassays indicated that diafenthiuron, propargite, dicofol, monocrotophos, ethion and oxydemeton methyl were found respectively 1402.38, 361.35, 198.32, 20.31, 5.21 and 2.13 times more toxic than dimethoate against eggs. Sulphur did not show any ovicidal action. These pesticides and sulphur were more toxic than dimethoate against both the larval and nymphal stages of the mite. Regarding adulticidal action-diafenthiuron, propargite, dicofol, monocrotophos, ethion, oxydemeton methyl and sulphur were found respectively 516.43, 162.58, 60.45, 28.75, 6.76, 1.87 and 1.45 times more toxic than dimethoate. Diafenthiuron proved to be the most effective pesticide against different stages of the mite followed by propargite and dicofol. However, oxydemeton methyl and dimethoate were the least effective. Rest of the pesticides were moderate in their response.
H. R. Rohilla - One of the best experts on this subject based on the ideXlab platform.
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Toxicity of nitroguanidines/neonicotinoids and conventional insecticides against leafhopper Amrasca biguttula biguttula on okra under screen-house
Indian journal of entomology, 2003Co-Authors: S S Ravikumar, B S Chhillar, H. R. RohillaAbstract:Studies on the toxicity of two neonicotinoids i.e. thiamethoxam and imidacloprid and few commonly used insecticides viz., Oxydemeton-Methyl, dimethoate, fenvalerate, monocrotophos and malathion were undertaker} against the third instar nymphs of Amrasca biguttula biguttula (Ishida) (Hisar strain) on okra under screen-house condition. The respective LCso values (%) were 0.000314, 0.000813, 0.005927, 0.006273, 0.008110, 0.025100 and 0.02690 per cent, respectively. Thiamethoxam was 85.95 times more toxic than malathion, the least toxic one.
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toxicity of nitroguanidines neonicotinoids and conventional insecticides against leafhopper amrasca biguttula biguttula on okra under screen house
Indian journal of entomology, 2003Co-Authors: S S Ravikumar, B S Chhillar, H. R. RohillaAbstract:Studies on the toxicity of two neonicotinoids i.e. thiamethoxam and imidacloprid and few commonly used insecticides viz., Oxydemeton-Methyl, dimethoate, fenvalerate, monocrotophos and malathion were undertaker} against the third instar nymphs of Amrasca biguttula biguttula (Ishida) (Hisar strain) on okra under screen-house condition. The respective LCso values (%) were 0.000314, 0.000813, 0.005927, 0.006273, 0.008110, 0.025100 and 0.02690 per cent, respectively. Thiamethoxam was 85.95 times more toxic than malathion, the least toxic one.
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Occurrence of insecticide resistance in leafhopper, Amrasca biguttula biguttula (Ishida) on Okra
Journal of entomological research, 2001Co-Authors: V. K. Kalra, H. R. Rohilla, R.s. Jaglan, Ram Singh, Ritu Saini, Roma Chauhan, S.s. SharmaAbstract:Insecticides are proving ineffective against the adults of Amrasca biguttula biguttula on okra at Hisar. Toxicity of various insecticides viz., malathion, oxydemeton methyl, phosphamidon, dimethoate, thiamethoxam, endosulfan and monocrotophos was studied against this leafhopper and the LC50 values (%) were 1.097, 0.126, 0.112, 0.178, 0.000447, 0.063 and 0.063, respectively. Thiamethoxam was the most toxic i.e. 2454 times more toxic than malathion which was least toxic. Imidacloprid gave more than 80 per cent mortality of this pest at 4 times lower the normal concentration (0.000225%) while fenvalerate could not bring about even 20 per cent mortality at 30 times the normal concentration (0.15%) indicating development of resistance in leafhopper to the commonly recommended insecticides.
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Effect of simulated rains on persistent toxicity of Oxydemeton-Methyl to mustard aphid (Lipaphis erysimi) on mustard (Brassica juncea) crop
Indian Journal of Agricultural Sciences, 2000Co-Authors: G. S. Yadav, R. Chauhan, H. R. RohillaAbstract:Effect of simulated rains of 0,2,4, 6, 10 and 15 mm done by knapsack sprayer at 0, 2, 4, 8, 12, 24, 48 and 72 hr after oxydemeton.methyl 0.025% spray on its persistent toxicity to Lipaphis elysimi (Kalt.) infesting 'RH 30' mustard, Brassica juncea (L.) Czem and Coss crop was studied during 1992-93 and 1993-94. Ten apterous adult aphids were released on potted mustard plant leafat 0, 1,3,5,7,10 and 15 days after insecticidal spray followed by simulated rain and later enclosed in a cage. Aphid mortality was recorded 24 hr after each release. The aphid mortality decreased with increasing rain level. The persistent toxicity of Oxydemeton-Methyl in rain control (no rain but insecticidal spray) was 900 as against 698, 624, 632,599 and 414 in sets receiving 2, 4, 6,10 and IS nun rain respectively during 1992-93. During 199394 persistent toxicities were 805 in rain control and 610, 619, 593,590 and 424 in differentrainIevels. Rain occurring upto 12 hr after Oxydemeton-Methyl spray brought much reduction in persistent toxicity as compared to those occurring 24, 48 and 72 ht after the spray. If rain of 15 mm occurs 48 hr after Oxydemeton-Methyl spray than there is no need of its reapplication.
S. Lingappa - One of the best experts on this subject based on the ideXlab platform.
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Selective Toxicity of some Insecticides against Tobacco Aphid, Myzus nicotianae Blackman and its Predator, Cheilomenes sexmaculata (Fabricius)
Journal of Biological Control, 2000Co-Authors: C. S. Patil, S. LingappaAbstract:Studies were conducted to assess toxicity of promising insecticides against tobacco aphid, M. nicotianae and its predator, C. Sexmaculata during 1995 at the Agricultural Research Station, Nipani (Karnataka). The selectivity ratio of M. nicotianae and C. sexmaculata grubs and adults was lowest for acepbate followed by imidacloprid and oxydemeton methyl. However, endosulfan registered highest selectivity ratio and it could be used for aphid control along with the coccinellids in an integrated approach.
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Sensitivity of tobacco aphid in relation to pesticide usage
Journal of the Maharashtra Agricultural Universities, 2000Co-Authors: C. S. Patil, S. LingappaAbstract:The sensitivity of Myzus nicotianae to dimethoate and oxydemeton methyl was high in the population collected from the low pesticide usage vts-a-vis heavy pesticide usage area. While such a variation was invisible with respect to endosulfan.
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Persistent Toxicity of Insecticides against Cheilomenes sexmaculata (Fabricius), a Predator of Tobacco Aphid, Myzus nicotianae Blackman
Journal of Biological Control, 1999Co-Authors: C. S. Patil, S. LingappaAbstract:Persistent toxicity of insecticides to Cheilomenes sexmaculata (Fabricius) was studied during 1994-95. Acephate, imidacloprid and carbosulfan exhibited considerable indirect toxic effect on the population of C. sexmaculata . However, oxydemeton methyl was relatively safe to C. sexmaculata .
