Impact of 2,4-D and fipronil on the tropical midge Chironomus sancticaroli (Diptera: Chironomidae)

Author(s)

da Silva Pinto, Thandy Junio ^{[1, 2]} ; Moreira, Raquel Aparecida ^{[1, 2]} ; Menezes da Silva, Lais Conceicao ^{[1, 2]} ; Cardoso Yoshii, Maria Paula ^{[1, 2]} ; Goulart, Bianca Veloso ^[3] ; Fraga, Priscille Dreux ^{[1, 2]} ; Montagner, Cassiana Carolina ^[3] ; Daam, Michiel Adriaan ^[4] ; Gaeta Espindola, Evaldo Luiz ^{[1, 2]}

Affiliation

^[1] Univ Sao Paulo, Sao Carlos Sch Engn, PPG SEA, Ave Trabalhador Sao Carlense 400, BR-13560970 Sao Carlos - Brazil

^[2] Univ Sao Paulo, Sao Carlos Sch Engn, NEEA, CRHEA, SHS, Ave Trabalhador Sao Carlense 400, BR-13560970 Sao Carlos - Brazil

^[3] Univ Estadual Campinas, Inst Chem, Analyt Chem Dept, Campinas, SP - Brazil

^[4] Univ Nova Lisboa, Fac Sci & Technol, Dept Environm Sci & Engn, CENSE, P-2829516 Caparica - Portugal

• Document type: Journal article
• Source: ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY; v. 209, FEB 2021.
• Web of Science Citations: 0

Abstract

Increased use of pesticides in conventional agriculture implies potential risks to the environment. In aquatic ecosystems, benthic organisms may be exposed to pesticides via contaminated water and sediment, leading to several potential cascading effects on the food web. The aim of this study was to assess the functional implications of environmental realistic concentrations of the herbicide 2,4-D and the insecticide fipronil (alone and in combination) to the native tropical chironomid Chironomus sancticaroli. These two pesticides are widely applied to different crops and have frequently been detected (together) in surface water bodies in Brazil and elsewhere. Commercial products containing fipronil (Regent (R) 800WG) and 2,4-D (DMA (R) 806BR) were evaluated in 8-day toxicity tests for their effects on larval survival, growth (body length and biomass), head capsule width, development, and mentum deformities. Fipronil decreased the larval survival at the highest test concentration and the effective concentrations (EC) after eight days of exposure were: EC10 = 0.48 mu g L-1 (0.395-0.565), EC20 = 1.06 mu g L-1 (0.607-1.513), and EC50 = 3.70 mu g L-1 (1.664-5.736). All sublethal test concentrations of fipronil decreased the larval growth, causing reductions in biomass up to 72%. The two highest test concentrations of fipronil decreased the head capsule width and after exposure to 3.7 mu g fipronil L-1, only half of the larvae reached the fourth instar. The incidence of deformities was increased by fipronil in a concentration dependent manner with an increase ranging from 23% to 75%. The highest test concentration of 2.4-D (426 mu g L-1) decreased the head capsule width, but larval development was unaffected at all concentrations evaluated. In the mixture tests, antagonism was observed at lower fipronil concentrations and synergism at higher fipronil concentrations for growth. The incidence of deformities rose with increasing fipronil concentrations. The results showed that environmental realistic concentrations of fipronil may have serious ecological implications for C. sancticaroli populations and that a mixture with the herbicide 2,4-D can have synergistic effects, potentiating the risks to the aquatic ecosystem. (AU)

• FAPESP's process: 15/18790-3 - Environmental effects of the pasture-sugarcane conversion and pasture intensification
• Grantee: Luiz Antonio Martinelli
• Support Opportunities: Research Program on Global Climate Change - Thematic Grants
• FAPESP's process: 17/24126-4 - EFFECTS OF THE PESTICIDES FIPRONIL AND 2,4-D, ISOLATELY AND IN MIXTURE, ON NATIVE SPECIES OF THE NEOTROPICAL AQUATIC BIOTA
• Grantee: Raquel Aparecida Moreira
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 19/04198-6 - Impacts of sugarcane vinasse on neotropicals benthic aquatic macroinvertebrates
• Grantee: Priscille Dreux Fraga
• Support Opportunities: Scholarships in Brazil - Scientific Initiation