Evaluation of bio-efficacy and compatibility of emamectin benzoate with neem based biopesticide against fruit borers of brinjal and okra

Bio-efficacy and physical compatibility of biorational insecticides, viz. emamectin benzoate and Neem Baan® was investigated against brinjal shoot and fruit borer, Leucinodes orbonalis Guenne and okra shoot and fruit borer, Earias vittella Fab. under field conditions during kharif 2010 and 2011. Both biorationals were found compatible with each other by using jar test and emulsion stability. The results revealed that in both brinjal and okra there was no phytotoxicity observed due to emamectin benzoate with Neem Baan® combination. The lowest per cent fruit infestation was observed in the treatment of emamectin benzoate combined with Neem Baan® @ 7 ml per litre of water, i e 7.36% and 5.39% on number basis and 8.13% and 5.77% on weight basis in brinjal during kharif 2010 and 2011 respectively. Also the highest marketable fruit yield in weight basis was also obtained in the treatment (12.35 tonnes/ ha and 16.89 tonnes/ha) during kharif 2010 and 2011. Similarly, in okra also it recorded lowest fruit infestation (5.92% and 5.59%) and highest marketable yield (1.62 tonnes/ha and 2.19 tonnes/ha) in 2010 and 2011 on weight basis. Further, it was observed that the plant parameters like shoot length and number of flowers recorded significantly higher in the treatment of emamectin benzoate combined with Neem Baan® than untreated control (T8) in both the years. The results indicated that the combination of neem formulation with emamectin benzoate was effective in managing L. orbonalis and E. vitella

Relative susceptibility of the Bikaner and Delhi populations of mustard aphid, Lipaphis erysimi (Kalt.) (Homoptera: Aphididae), and its predator, Coccinella septempunctata L. (Coleoptera: Coccinellidae), to different insecticides

A study was undertaken to assess the effectiveness of five insecticides against the Delhi and Bikaner populations of mustard aphid, Lipaphis erysimi (Kalt.), using the leaf dip method, and against Coccinella septempunctata L. in semi-field conditions. Acetamiprid and thiamethoxam were found to be more toxic than other insecticides. After 24 h, the LC50 values for the Bikaner population against different insecticides were 7.0, 6.0, 4.0, 3.0 and 2.0 ppm for carbosulfan, bifenthrin, imidacloprid, acetamiprid and thiamethoxam, respectively. Similarly, the descending order of toxicity for the Delhi population was acetamiprid (7.0 ppm), thiamethoxam (9.0 ppm), imidacloprid (15.0 ppm), carbosulfan (32.0 ppm) and bifenthrin (36.0 ppm). The relative toxicity values suggest that in both populations, thiamethoxam and acetamiprid show the highest toxicity. Carbosulfan and bifenthrin were highly toxic to coccinellid grubs and resulted in 100% mortality in semi-field conditions, whereas the neonicotinoids acetamiprid and thiamethoxam showed less mortality. It showed the tolerance of coccinellidae against neonicotinoids under semi-field conditions.Une étude a été menée pour connaître l’efficacité de cinq insecticides sur des populations du puceron de la moutarde, Lipaphis erysimi (Kalt.), de Delhi et de Bikaner en utilisant le procédé de résidu de feuille, ainsi que sur Coccinella septumpunctata L. en condition semi-naturelle. L’acétamipride et le thiaméthoxame se sont révélés plus toxiques que les autres insecticides. Après 24 h, les valeurs de LC50 pour la population de Bikaner en réaction aux différents insecticides étaient de 7,0, 6,0, 4,0, 3,0 et 2,0 ppm pour le carbosulfan, la bifenthrine, l’imidaclopride, l’acétamipride et le thiaméthoxame, respectivement. De même, l’ordre décroissant de toxicité pour la population de Delhi était l’acétamipride (7,0 ppm), le thiaméthoxame (9,0 ppm), l’imidaclopride (15,0 ppm), le carbosulfan (32,0 ppm) et la bifenthrine (36,0 ppm). Les valeurs de toxicité relatives ont démontré que dans les deux populations, le thiaméthoxame et l’acétamipride avaient la plus haute toxicité. Le carbosulfan et la bifenthrine étaient fortement toxiques aux larves de coccinelles et ont provoqué la mortalité de 100 % de la population en condition semi-naturelle, tandis que les néonicotinoïdes, l’acétamipride et le thiaméthoxame ont engendré moins de mortalité. Cela démontre la tolérance des coccinelles aux néonicotinoïdes en condition semi-naturelle

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Lethal and Sublethal Effects of Insecticides Used on Citrus, on the Ectoparasitoid Tamarixia radiata

Huanglongbing (HLB) is a disease associated with the bacteria "Candidatus Liberibacter spp." and has been devastating citrus orchards around the world. Its management involves control of the insect vector, the Asian citrus psyllid Diaphorina citri Kuwayama. However, the indiscriminate use of chemicals has caused pest outbreaks and eliminated the natural enemies of the vector, such as the parasitoid Tamarixia radiata (Waterston), the main agent for biological control of D. citri. This study assessed the lethal and sublethal effects of insecticides recommended for integrated production of citrus on the parasitoid T. radiata. When adult parasitoids were exposed to residues of 25 insecticides, 20% of them, i.e., gamma-cyhalothrin, etofenprox, azadirachtin, tebufenozide and pyriproxyfen, were considered as harmless (Class 1), 12% as slightly harmful (Class 2), 12% as moderately harmful (Class 3) and 56% as harmful (Class 4), according to the classification proposed by the IOBC/WPRS. Afterward, 14 insecticides (5 harmless and 9 harmful) were sprayed on the parasitoid pupae. Of the 14 insecticides tested, only the organophosphates dimethoate and chlorpyrifos affected the parasitoid emergence. The effects of insecticides on the parasitism capacity of adults exposed to residues of azadirachtin, etofenprox, gamma-cyhalothrin, pyriproxyfen and tebufenozide (harmless) were also evaluated. Tebufenozide and gamma-cyhalothrin affected the parasitism of the F0 generation, but did not affect the emergence of the F1 and F2 generations. Therefore, for an effective IPM program, selective insecticides or harmful pesticides to adult parasitoids could be used in the field, provided that the adults do not occur naturally and the chemical applications do not coincide with parasitoid releases