Journal article
Investigations on side effects of various neem products on Daphnia magna Straus (Crust.: Cladocera)



Publication Details
Authors:
Saucke, H.; Schmutterer, H.
Publication year:
1992
Journal:
Anzeiger für Schädlingskunde Pflanzenschutz Umweltschutz
Pages range:
121-126
Volume number:
65

Abstract
The possible side-effects of the neem products NeemAzal-S (Azal), Azt-Extract (AZT), Margosan-O | (Margosan) and aque- ous neem seed kernel extract (NSKE) on Daphnia magna, the water flea, were investigated under laboratory conditions. A 48h immobilisation test was conducted using 6-24h old juveniles of D. magna. The 48 h-ECs0 in rag/1 and the corres- ponding azadirachtin concentrations in ppm were for Azal 12.3 mg/l (0.04 ppm), for AZT-extract 29.3 mg/l (0.34 ppm), for Margosan-O 103mg/l (0.19ppm) and for NSKE 1128mg/1 (3.38 ppm). 48 h exposure of young water fleas to the EC10 and subsequent rearing for 3 weeks in uncontaminated water caused no reduction of the growth rate. Semi-static tests using juveniles and adults of an age of 21 days led to increased mortality but surviving juvenile water fleas developed with slightly reduced growth rates and reached maturity. Surviving adults produced viable, morphologically normal progeny in reduced number. There were no difficulties during moults. In the described tests the formulated products were more effective than NSKE in the order Azal > AZT > Margosan > NSKE. The missing correla- tion between the observed effects and the content of the main insecticidal ingredient azadirachtin in the neem products leads to the conclusion that the major factors for toxicity of the formulated products are emulsifiers and/or other products. The possible impact of neem products on aquatic microcrustaceans when used for pest control measures or as fertilizers in rice fields is discussed


Authors/Editors

Last updated on 2014-06-03 at 10:36