Journal of Basic and Applied Zoology (Feb 2019)
Impact of some new generation insecticides on soil arthropods in rice maize cropping system
Abstract
Abstract Background Soil is the backbone of agriculture, and soil arthropods and earthworms are one of the key factors for maintaining soil physical characters. Densities of these populations are also an indicator of soil fertility. Several insecticides are now applied in field to manage different borer insects and get deposited in soil. They may exert impact on the inhabitants of soil. Methods Seven different insecticides chemistry were evaluated to find out the impact (if any) on soil arthropods and earthworms in field condition. Simultaneously, richness of soil arthropods was enumerated using pitfall trap. Result The arthropod diversity present in the experimental site has 92.58% richness of class insecta population; of which the order hymenoptera accounts for 57.34%. Other than class insecta, representatives of class arachnida, diplopoda, chilopoda, annelida, and crustacea are also recorded. Rynaxypyr, cartap hydrochloride, fipronil, and chlorpyrifos showed no significant detrimental effect on the collembola population present in soil. Then, 27.65% and 13.47% reduction of collembola population was noted in the case of carbofuran- and phorate-treated plot. Several minute soil arthropods recorded during experiment includes minute ants, beetles, and soil oribatid mites pseudoscorpions. No appreciable toxic effect was noticed by the insecticides on the basis of mean population count over control. Carbofuran recorded the highest population of earthcasts (15.59% more over untreated check), while imidacloprid, chlorpyrifos, and phorate showed negative impact. Imidacloprid showed maximum toxicity toward the redworm. Further, 33.14% reduction of population was recorded by imidacloprid and chlorpyrifos which also showed toxicity toward Eisenia fetida L, while rynaxypyr and fipronil recorded more population over control. Cartap hydrochloride, carbofuran, and phorate did not pronounce toxic impact on redworm. Conclusion Collembola population was less sensitive toward rynaxypyr, cartap hydrochloride, fipronil, and chlorpyrifos. Imidacloprid, chlorpyrifos, and phorate showed negative impact on earthworm.
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