Efficacy of new molecules against green leafhopper in rice (original) (raw)
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Pymetrozine : An effective insecticide for management of planthoppers in rice
2019
Eight insecticidal treatments including pymetrozine 50% WG at 100, 125, and 150 g a.i./ha, imidacloprid 200 SL @ 25 g a.i./ha, dinotefuran 20 SG @ 30 g a.i/ha, sulfoxaflor 24 SC @175 g a.i/ha, flonicamid 50 WG @ 75 g a.i./ha and buprofezin 25 SC @ 200 g a.i/ha were field evaluated against brown panthopper and white-backed planthopper in rice along with untreated control at Central Research Farm, Department of Entomology, Orissa University of Agriculture and Technology (OUAT), Bhubaneswar during Kharif, 2015. It was revealed that pymetrozine 50% WG 150 g a.i./ha proved to be the superior insecticide against brown planthoppers and white backed planthoppers exhibiting maximum per cent reduction over control followed by pymetrozine 50% WG 125 g a.i./ha. The least effective insecticide was imidacloprid 200 SL @ 25 g a.i./ha.
Effect of new insecticide molecules on predators of rice ecosystem
Field experiment was conducted to evaluate the toxicity of newer insecticide molecules viz., imidacloprid 17.8 SL, thiamethoxam 25 WG, acetamiprid 20 SP, sulfoxaflor 25 SC, dinotefuran 20 SG, pymetrozine 50 WG, buprofezin 25 SC, monocrotophos + dichlorvos 36 SL + 76 EC against spiders and mirid bugs of rice ecosystem in Agricultural College Farm, Bapatla during kharif 2015. Among all the insecticides pymetrozine 50 WG @ 0.5 g l-1 proved safer to the green mirid bugs with lowest percent mortality of 16.96 redcution over precount after two rounds of spray. The safest treatment to spiders is sulfoxaflor with 20.40 percent mortality of spiders over precount followed by pymetrozine 50 WG @ 0.5 g l-1 (23.89 percent).
Bio-efficacy of ethiprole 10.7 % + pymetrozine 40 % WG against brown planthopper in rice
Laboratory and field experiments were conducted at Annamalai University, Department of Entomology, Chidambaram during 2018-2020 to evaluate the bio-efficacy of ethiprole 10.7 % + pymetrozine 40 % WG against brown planthopper in rice. The results revealed that ethiprole 10.7 % + pymetrozine 40 % WG @ were effective in the management of brown planthopper. Ethiprole 10.7 % + pymetrozine 40 % WG was found to be safer on natural enemies viz., spiders and mirid bugs. The highest yield were obtained from ethiprole 10.7 % + pymetrozine 40 % WG @ treated plots in both seasons.
A field trail was conducted at Agricultural College Farm, Bapatla during kharif 2015 to evaluate the efficacy of imidacloprid 17.8 SL, thiamethoxam 25 WG, acetamiprid 20 SP, sulfoxaflor 25 SC, dinotefuran 20 SG, pymetrozine 50 WG, buprofezin 25 SC, monocrotophos + dichlorvos 36 SL + 76 EC against brown planthopper in rice ecosystem. The data on planthoppers inferred that pymetrozine 50 WG @ 0.5 g l -1 proved to be the most effective insecticide in reducing population by recording highest per cent population reduction (62.98%) over untreated control. The insecticide dinotefuran 20 SG @ 0.4 g l -1 (59.60 %) was on par with pymetrozine in suppressing the pest population and also these three chemicals recorded with the highest grain yields 5266 and 5228 kg ha -1 .
The nymphs and adults of white-backed planthoppers (Sogatella furcifera, Howard) remove plant sap resulting in yield loss. Indiscriminate use of insecticides, results in the development of resistance by insects and ill effects on the environment opening the new era of chemicals with novel modes of action with good bioefficacy, higher selectivity, low mammalian toxicity and safety to the environment. Therefore, the introduction of newer insecticide molecules with alternate modes of action will play a serious role in pest management programs. Hence, an experiment was conducted to evaluate the bioefficacy of ethiprole + pymetrozine against white-backed planthopper of rice (ADT-46) under laboratory and field conditions at Annamalai University, Chidambaram during 2018-20. Ethiprole + pymetrozine @ (T1-36.91 + 138), (T2-40.13 + 150) and (T3-45.47 + 170) g a.i ha-1 with standard checks T4-pymetrozine @ (150) g a.i ha-1 , T5-buprofezin @ (200) g a.i ha-1 and T6-ethiprole + imidacloprid @ (50 + 50) g a.i ha-1 were evaluated against white-backed planthopper. The standard checks were of positive control i.e., reference insecticides which is in common use The results revealed that T3 recorded the lowest population of white-backed planthopper/ hill at 15 day after spraying (1.13 hoppers/hill in August-December 2018 and 1.79 hoppers/hill in August-December 2019 respectively) giving better yield. The population of natural enemies was comparatively lower in all insecticidal treatments than in the control.
A field trail was conducted at Agricultural College Farm, Bapatla during kharif 2015 to evaluate the efficacy of imidacloprid 17.8 SL, thiamethoxam 25 WG, acetamiprid 20 SP, sulfoxaflor 25 SC, dinotefuran 20 SG, pymetrozine 50 WG, buprofezin 25 SC, monocrotophos + dichlorvos 36 SL + 76 EC against brown planthopper in rice ecosystem. The data on planthoppers inferred that pymetrozine 50 WG @ 0.5 g l-1 proved to be the most effective insecticide in reducing population by recording highest per cent population reduction (62.98%) over untreated control. The insecticide dinotefuran 20 SG @ 0.4 g l-1 (59.60 %) was on par with pymetrozine in suppressing the pest population and also these three chemicals recorded with the highest grain yields 5266 and 5228 kg ha-1.
Pymetrozine: A Pyridine Azomethine insecticide for management of rice brown planthopper in India
Field trail was conducted at Agricultural College Farm, Bapatla during, kharif 2015 to evaluate the bio- efficacy of eight new insecticide molecules against Brown planthopper, and their impact on natural enemies. The pooled data on planthoppers after two sprays revealed that pymetrozine 50 WG was the best insecticide in controlling planthopper population and recorded with 62.98 per cent reduction over control followed by dinotefuran 20 SG and sulfoxaflor 25 SC. The traditional neonicotinoid imidacloprid, acetamiprid and thiomethoxam was proved ineffective in reducing the planthopper population. Pymetrozine ranked first in safety to green miridbugs (1:0.76) and spiders (1:0.07) as per the pest defender ratios and significantly superior to all other treatments. The highest yield was recorded in the buprofezin 25 SC treated plot (5.4 t ha-1) and was on par with pymetrozine 50 WG (5.2 t ha-1).
Bio-efficacy of certain insecticidal molecules against lepidopteran pests of rice
International journal of chemical studies, 2020
Rice is one of the most important food crops grown worldwide. Though we use almost of the improved agronomic practices, we can not get optimum production and productivity. The reason behind its low productivity includes several factors. Among them insect pest infestation is prime and most important one. Among several insect pests, pests of lepidopteran order such as yellow stem borer and leaf folder are considered as most destructive and responsible for severe yield losses. As the larva are found inside the stem or within the leaf fold, cultural, mechanical, physical methods of pest management are not as effective as chemical control in reducing the pest population. So the present investigation was carried out in order to find out the efficacy of certain chemicals against lepidopteran pests infesting rice.
Evaluation of selected insecticides against brown planthopper and their impact on natural enemies
The present investigation on the effectiveness of different insecticides against the brown planthopper, Nilaparvata lugens (Stal.), on rice in field conditions demonstrated that pymetrozine 50% WG @ 150 g a.i./ha was found to be the most efficient chemical, recording the highest overall percent decline in BPH population, i.e., 76.88 percent and 79.86 percent after both the initial and second sprays, accordingly. Pymetrozine was succeeded by sulfoxaflor 24% SC @ 175 ml a.i./ha, which recorded 75.10 percent and 74.49 percent reduction. Pymetrozine 50% WG, with 2.21 BPH/hill after first spray and BPH/hill after second spray, had the lowest overall mean population of BPH, followed by sulfoxaflor 24% SC, with 2.38 BPH/hill after first spray and 2.28 BPH/hill after second spray. All the treatments reported safer to the population of spiders and coccinellids among them pymetrozine 50% WG recorded higher mean population of spiders 2.44 and coccinellids 1.08 per hill in comparison with untreated plot.
Safety Selected Insecticides to Predators and Egg Parasitoids of Planthoppers in Rice Ecosystem
The research safety selected insecticides to predators and egg parasitoids of planthoppers in rice ecosystem was carried out in the wet season of 2014 at Subang District. The several insecticides of mixture chlorantranilprole + thiamethoxam, pymetrozine, emamectin benzoate and deltamethrin were sprayed on rice plots at 20 and 35 days after transplanted (dat). Observation to planthoppers and predators by visual counting, while observation to egg parasitoids through parasitism by BPH eggs trap. The result showed that pimetrozine had reduced BPH population, followed by chlorantranilprole + thiamethoxam. In the other hand chlorantranilprole + thiamethoxam, pimetrozine and deltamethrin had reduced WBPH population. Insecticides of chlorantranilprole + thiamethoxam, pymetrozine, emamectin benzoate and deltamethrin highly safety against L. pseudoannulata, P. fuscipes, and Coccinella sp., but those insecticides moderately safety to O. nigrofasciata and spiders (without L. pseudoannulata). Insecticides of chlorantranilprole + thiamethoxam, emamectin benzoate and deltamethrin moderately safety against C. lividipennis, but pymetrozine moderately unsafety to this predator. Chlorantranilprole + thiamethoxam were moderately unsafety to parasitism of eggs parasitoids Anagrus sp., but was moderately safety to parasitism of eggs parasitoids Oligosita sp.. Pymetrozine and emamectin benzoate were moderately safety to Anagrus sp., but moderately unsafety to Oligosita sp.