CONTENT OF PESTICIDE RESIDUES IN THE FLOWERS OF THE ACACIA AND LINDEN TREES FROM THE MOLDAVIAN CODRI AREA.

The purpose of this research was to assess the conformity of the forest melliferous flora with organic apiculture, regarding concentrations of systemic pesticides, to predict the production of bio apicultural products. Flowers of the forest trees of white acacia (Robinia pseudoacacia) and large-leaf linden (Tilia platyphillos), which are the main sources of nectar and pollen for honey bees, were studied for the presence of 17 more commonly spread pesticides: pyrethroid insecticides (Cypermethrin, Deltamethrin, Pyrethrin, Tau-fluvalinate), neonicotinoid insecticides (Imidacloprid, Clothianidin, Thiamethoxam), organophosphorus insecticides (Fenamifos), triazole fungicides (Difenoconazole, Fenhexamid, Mepanipyrim, Cyprodinil), acaricides (Fipronil) and herbicides (Amidosulfuron, Amitrol, Glyphosate, Sulfosulfurol). Of the 17 investigated pesticides, in the white acacia flowers, 14 pesticide residues were found: Cypermethrin, Deltamethrin, Pyrethrin, Clothianidin, Fenamifos, Difenoconazole, Fenhexamid, Mepanipyrim, Cyprodinil, Fipronil, Amidosulfuron, Amitrol, Glyphosate and Sulfosulfurol. Average concentrations of pesticides residues in acacia flowers ranged from 0.003 mg/kg for Mepanipyrim and Fipronil, to 8.75 mg/kg for Difenoconazole and 0.25 mg/kg to Glyphosate. In the large-leaf linden flowers, out of the 17 investigated pesticides, the residues of 13 pesticides were registered, including 3 pyrethroid insecticides, 1 neonicotinoid insecticide, 1 organophosphorus insecticide, 3 triazole fungicides, 1 acaricide and 4 herbicides. Average concentrations of pesticide residues in the linden flowers ranged from 0.001 mg/kg for Fipronil up to 16.0 mg/kg for Difenoconazole and 1.25 mg/kg for Glyphosate. The obtained data attest that in the flowers of forest trees are detected low concentrations of residues of pyrethroid insecticides (Cypermethrin, Deltamethrin, Pyrethrin) from 0,003 up to 0,100 mg/kg, of neonicotinoid insecticide (Clothianidin) from 0,400 up to 0,425 mg/kg, of organophosphorus insecticide (Fenamifos) in an amount of 0.042 mg/ kg, triazole fungicides (Fenhexamid, Mepanipyrim, Cyprodinil) from 0,017 to 0,092 mg/kg, triazole fungicide Difenoconazole from 8,75 to 16,0 mg/kg, acaricide Fipronil from 0,001 up to 0,003 mg/kg, herbicides (Amidosulfuron, Amitrol, Sulfosulfurol) from 0,005 up to 0,013 mg/kg and herbicide Glyphosate from 0,25 up to 1,25 mg/kg. The detected concentrations of pesticide residues in the tree flowers (white acacia and large-leaf linden) was from 1.3 to 33.3 times lower than the maximum admisibil limits, according to national and EU standards. Therefore, the recorded pesticide residues in the flowers of forestry trees, are not harmful for the health of bees and fauna of studied ecosystem. In conclusion we can say that the flora of studied by us forest sector, are not polluted with pesticides, so organic beekeeping can be practiced here, with the production of organic apiculture products. [ABSTRACT FROM AUTHOR]