Study of the effects of glyphosate application on Collembola populations under controlled conditions

Abstract

Glyphosate is the most widely used herbicide worldwide. However, the effects of this molecule on non-target populations are still a subject of study. The objective of this research was to determine the effect of the application of different glyphosate doses on variation in collembolan (springtail) populations. To accomplish this goal, samples of organic substrate that contained different collembolan populations were collected. Samples were taken to the laboratory and acclimatized for 48 hours. Glyphosate C14 was then applied to the samples in doses equivalent to 0 L ha-1, 2 L ha-1, and 4 L ha-1 under a completely randomized experimental design with three treatments and five replicates. Population counts were performed by implementing the flotation method at 0, 4, 7 and 11 days after application (DAA). We found that individuals were distributed in the families Isotomidae and Entomobryidae and divided into species of the genus Proisotoma (Börner), Lepidocyrtus (Bourlet) and Seira (Lubbock). A decrease in the number of arthropods between 40% and 60% was reported for the treatments with herbicide application at 4 and 7 DAA, showing a drop in the size of the community in those treatments in which the herbicide was applied compared to the control. However, no differences were observed between herbicide doses. Additionally, the presence of glyphosate C14 was demonstrated in dead individuals. This confirms a possible effect of the herbicide on some biological systems that led to a decrease in the size of the population.