Researches were carried out for the determination of some insecticides toxicity used actually on large scale in the agricultural practice, towards the pollinating bees from the alfalfa cultivation, under the condition from the South-Western part of Romania. The previous researches in our country were performed by Cârnu, Ciurdărescu, Paulian et al., Bura et all. The researches were made under field conditions, in the alfaalfa   from the experimental field of the Didactic Station Timişoara, during 2007-2008. There were used insulators with an area of 1 m 2 . Sprayings with insecticides were performed; 50 bees were introduced in each insulator and the mortality was supervised after 4, 8, 24 and 48 hours. The following insecticides were used: Fastac 10 EC (alfa-cypermethrin) - 0.15 l/ha, Sinoratox 35 CE (dimethoate) 1.5 l/ha, Decis 2.5 EC (deltamethrin)- 0.3 l/ha. Each variant was performed in three replications and compared with the untreated control variant. A moderate toxicity presented Fastac 10 EC. The researches on the toxicity of some insecticides to alfalfa pollinators have not been subject to such investigations in the South-Western part of Romania. The results achieved represent original contributions to the knowledge regarding the pollinating insects and their protection for obtaining an increased alfalfa qualitative and quantitative seed yield.

toxicity; insecticides; bees alfaalfa

Presentation: oral