Responses of macroinvertebrate communities to pesticide application in irrigated rice fields

Abstract

The ability to recover to original states after disturbances makes macroinvertebrates useful tools for assessing the impacts of pesticides. Many studies showed that direct exposure to pesticides decreases macroinvertebrate richness and alters their composition. The main objective of this study was to assess recovery patterns in macroinvertebrate communities after pesticide application in irrigated rice fields. We analyzed short-term temporal dynamics of macroinvertebrate communities after application of the herbicides bispyribac-sodium and clomazone and the insecticide chlorantraniliprole, over the rice-growing season in southern Brazil. We selected three conventional rice fields and the recovery of macroinvertebrate communities was also compared with three adjacent natural ponds. The study was developed from November 2011 to February 2012 (rice-growing season). Five macroinvertebrate collections were carried out 3, 7, 14, 38, and 60 days after pesticide application (November 25). Rice fields showed lower richness and abundance than ponds in the period immediately after pesticide application, and recovery rates in the richness of macroinvertebrate communities were more conspicuous as pesticide residuals dissipated from the fields. Macroinvertebrate community structure in rice fields also became more similar to natural ponds as pesticide traces were scarcer. However, macroinvertebrate abundance patterns were not related to pesticide concentrations in the fields. Our results supported the general hypothesis on the negative effects of pesticide application on macroinvertebrate community in irrigated rice fields, although other environmental features (e.g., length of the flooded period) also contributed to explain temporal dynamics in the macroinvertebrate communities from irrigated rice fields.

Species richness and diversity of aquatic insects inhabiting rice fields in Bogor, West Java, Indonesia

“…The abundance of aquatic macroinvertebrates generally increases with water permanence, as more species can complete their life cycles. Therefore, the length of the flooded period has special importance in structuring rice field macroinvertebrates (Stenert et al 2018).…”

Effects of Agrochemicals on Freshwater Macroinvertebrates: Challenges and Perspectives from Southeastern Brazil

“…Gagliardi and Pettigrove () observed the incidence of morphological deformity, mainly in the mentum, in Chironomidae larvae collected near areas of tobacco cultivation in Australia. Stenert et al () showed a negative relationship between the richness of macroinvertebrates and the use of herbicides and pesticides in areas of irrigated rice crops in the Rio Grande do Sul, Brazil, where the richness reduced immediately after the application of pesticides in rice fields. The loss of genetic diversity has also been reported as a result of the exposure of aquatic macroinvertebrates to fungicides.…”

Combined impact of pesticides and other environmental stressors on animal diversity in irrigation ponds

“…Japan has approximately 200,000 irrigation ponds, most of which were constructed during the 17th to 19th centuries [18]. Despite their small size and the high risk of pesticide contamination and other stressors [19][20][21][22], the irrigation ponds can potentially sustain high taxonomic richness and make significant contributions to regional biodiversity [23][24][25][26]. Further, many endangered species inhabit the irrigation ponds [27]; the ponds function as refuges for various aquatic plants and wetland animals, because 61.1% of wetlands had already been lost by 2000 in Japan [18].…”