PW12 Pesticide II
Exhibit Hall
8:00 AM - Wednesday
(PW199) Pesticide effects on development, growth and weight of Chironomus riparius larvae in rice fields.
Faria, M1, Nogueira, AJA1, Soares, AMVM1, 1 Department of Biology, University of Aveiro, Portugal, Portugal
ABSTRACT- Drift from pesticide spray application can result in contamination of non target environments such as surface waters. However the impact of these compounds on river macroinvertebrates is difficult to assess due to the fast degradation of these compounds. To determine the pesticide water contamination effects on ecological parameters of Chironomus riparius larvae, in situ bioassays were performed in rice fields. Development, growth and weight of C. riparius larvae bioassays were carried out in channels in rice fields during the period of pesticide (molinate, endosulfan and propanil) spray. Bioassays were also run in laboratory conditions, in parallel to the in situ bioassays, with water from rice fields, to assess whether in situ and laboratory bioassays showed comparable results. Artificial sediment was used in all bioassays (lab and in situ). Body length growth was inhibited by the highest concentration of endosulfan, but development and weight of larvae were not affected by this insecticide. The herbicides molinate and propanil, did not affect development and growth of C. riparius larvae. Significant differences in body length growth between reference and contaminated water with endosulfan were found in laboratory and field tests.
Key words: Rice fields, Pesticides, Chironomus riparius