Effects of carbofuran and metsulfuron-methyl on the benthic macroinvertebrate community in flooded ricefields

Abstract

AIM: This study evaluated the effect of the insecticide carbofuran and the herbicide metsulfuron-methyl on the abundance and diversity of benthic macroinvertebrates in a paddy ricefield. METHODS: To achieve this goal, two pesticide treatments [the insecticide carbofuran (IC) and the herbicide metsulfuron-methyl (HM)] and a control (Co) treatment with no added pesticide were established in an experimental area of the Plant Science Department of the Federal University of Santa Maria. Soil samples were collected in triplicate from each treatment 30 days before and 1, 10, and 51 days after the pesticide application, for macrofauna identification. RESULTS: Among the 21 taxa identified, Trichoceridae was present only in Co, Hydroptilidae was recorded only in IC, and Corixidae in HM. In Co, the most abundant group was Annelida, while in IC and HM Diptera (Chironomidae) was dominant. Significant differences were observed between Co and IC, in the density of Odontoceridae (Control>IC) and Hydrophilidae (Control<IC), and between Co and HM in the density of Odontoceridae (Control>HM) and Hirudinea (Control<HM). CONCLUSION: In spite of the possible negative effects of the pesticides on the benthic community, the assemblages recovered rapidly.

Understanding the Degradation of Carbofuran in Agricultural Area: A Review of Fate, Metabolites, and Toxicity

“…A less significant degradation pathway of carbofuran is through the photolysis reaction. Carbofuran is not likely to accumulate in sunlight-exposed water and does not bioaccumulate (Baumart et al, 2011). The metabolic product of photolysis includes (Evert, 2002) 2,3-dihydro-2,2 dimethyl benzofuran-4,7-diol and 2,3-dihydro-3 keto-2,2 dimethyl benzofuran-7-yl carbamate (3-ketocarbofuran) (Mahalakshmi et al, 2007;Remucal, 2014).…”

Residues of Fungicides and Insecticides in Rice Field

“…Rice crops in majority are inserted in lowland areas, areas located close to watercourses and ground water. In this sense, studies analyzing residues of pesticides in irrigation water are also relevant, since the contamination of water sources may occur as a result of management practices and extravasation of irrigation water (Rodrigues et al, 2013), may reflect negatively on water quality, and thus present health risks to non‐target organisms, such as zooplankton community (Golombieski et al, 2008), benthic macroinvertebrates (Mize et al, 2008; Baumart et al, 2011), fish (Hussar et al, 2004; Nakagome et al, 2007; Toni et al, 2011) and also interfere in the quality of drinking water (Narita et al, 2014).…”