Abstract

This study was conducted to reveal the toxicity of sulfoxaflor and the four modern fungicides (ametoctradin +dimethomorph, isopyrazam, mandipropamid and propamocarb-HCl+fluopicolide) on various developmental stages of a non-target predatory mite, Amblyseius swirskii Athias-Henriot (Acari: Phytoseiidae). The maximum recommended concentrations of the pesticides were applied to eggs, larvae and adult females of the predator in order to obtain detail knowledge of their toxicity at worst-case scenario under laboratory conditions. Results indicated that mortality rates vary between the life stages and the larva was the most sensitive. The highest egg mortality was found for isopyrazam (20.44%) followed by propamocarb+fluopicolide (17.55%) and ametoctradin+dimethomorph (15.77%) at 72 h after the treatments. Sulfoxaflor, ametoctradin+dimethomorph and propamocarb+fluopicolide were proven to be harmful to the larvae as they caused significantly higher mortality than the control, and their mortality reached 80.00, 77.50 and 60.00% at 168 h after treatment, respectively. In the case of adult females, respective mortality rates of propamocarb+fluopicolide, sulfoxaflor, ametoctradin+dimethomorph and isopyrazam were found 30.00%, 25.83%, 21.66% and 16.66% after 120 h after treatment, respectively. In addition, mandipropamid and sulfoxaflor caused a drastic decrease in fecundity of the predator. Accordingly, isopyrazam may be compatible with A. swirskii in intergraded pest management programs where it is released as biological control agent. Due to their high toxicity to at least one developmental stage of the predator, further experiments are needed in order to clarify the toxicity of the other pesticides under field or semi-field conditions.