Effects of neonicotinoid insecticide formulations and their components on Daphnia magna – the role of active ingredients and co-formulants

ABSTRACT

Formulating agents used in pesticide products have been regarded as inactive/inert components; however, several studies confirmed additive, synergistic or antagonistic effects between the active ingredients (AIs) and additives, or the individual toxicity of the formulating agents. The worldwide used neonicotinoid insecticides and their components can reach surface waters, due to their physico-chemical properties (e.g. water solubility) or improper application in chemical plant protection technology, and can adversely affect non-target aquatic organisms. Formulated pesticides were analysed for alkane sulphonate surfactants by using liquid chromatography coupled with tandem mass spectrometry. In acute immobilisation tests on Daphnia magna, differences were found among the toxicity of the investigated neonicotinoid AIs and formulations. The toxicity of a formulated insecticide (Apache 50 WG®– AI: clothianidin) was found to be 46.5 times more toxic than explained by its AI, probably due to toxic effect of the formulating agents on D. magna. In contrast, two preparations (Calypso 480SC® – AI: thiacloprid, Actara 240 SC®– AI: thiamethoxam) were 2–3 times less toxic than their AIs. Results indicate possible synergistic/antagonistic interaction with the AIs.

KEYWORDS:

• Neonicotinoid
• adjuvant
• surfactant
• liquid chromatography–mass spectrometry
• Daphnia magna
• toxicity

Acknowledgement

The authors thank to Csilla Magor and Judit Juracsek for their technical support.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Hungarian Scientific Research Fund [OTKA K109865 and OTKA K112978].