I

ANNO 2 Numero 1
Fabio Sgolastra [1], Piotr Medrzycki [2], Donato Tesoriero [2], Anna Gloria Sabatini [2], Claudio Porrini [1]

Relationship between bee mortality and agrochemical treatments in the
vineyard areas of the Emila-Romagna Region

[1] Dipartimento di Scienze e Tecnologie Agroambientali – Area Entomologia, Università di Bologna (Italy)
[2] CRA -Istituto Nazionale di Apicoltura, Bologna (Italy)

Contact: cporrini@entom.agrsci.unibo.it

Grapevine treatments against Scaphoideus titanus Ball, the vector of Grapevine yellows (Flavescence dorée), often cause high bee mortality. In 2002 and 2003 a monitoring study was conducted in some vineyard areas of the Emilia-Romagna Region, in the period June-August, at the same time the treatments against S. titanus are applied. Bee mortality was assessed systematically using dead bee collection traps (underbasket) and dead bees in the traps were counted weekly. When the number of dead bees exceeded the threshold value of 250 dead bees/station/week, both chemical and palynological laboratory analyses were conducted. In 2002 the monitoring was conducted only in three provinces and the assessments were not systematic.
The most frequently found active ingredient was fenitrothion (100% in 2002; 94.1% in 2003), followed in 2003 by chlorpyrifos-ethyl (17.6%) and dimethoate and methyl-parathion (11.8%). The mean number of dead bees and the level of fenitrothion in the dead bee samples were higher in 2002 then in 2003. Surveys on the pesticides used in winegrowing holdings conducted by the Regional Plant Protection Service showed that winegrowers have progressed from a large-scale use of micro-encapsulated pesticides in 2002, to a more diversified use of agrochemicals in 2003. Our laboratory results showed that micro-encapsulated insecticides, when ingested by bees, explicate their action more slowly then EC-formulated, but their bee-harming effects are similar to those of other formulations. All these observations suggest that micro-encapsulated products may be more hazardous than EC- or WG-formulated pesticides. Furthermore, in some cases the palynological analyses revealed the presence of grapevine pollen on dead bees, which suggest that chemical treatments were applied also before grapevine bloom had completely ended.
We applied the Index of Environmental Hazards (IEH) to determine the degree of chemical contamination in the different monitored areas.