Alternatives to conventional insecticides to control berry moths and mealybugs in vineyards

According to the Directive 2009/128/EC synthetic pesticides should be gradually replaced by non-chemical measures and IPM implemented. Organophosphates and pyrethroids are still used in European vineyards despite their unfavorable ecotoxicological profile. At the same time, knowledge on the effects on non-target organisms of modern insecticides (e.g., IGRs, neonicotinoids, inhibitors of acetyl-CoA carboxylase) is limited. Alternatives to conventional pesticides in controlling some important pests of grapes (e.g. berry moths and mealybugs) were evaluated in Italy. A number of microbial and botanical insecticides (i.e. Bacillus thuringiensis, azadirachtin, Beauveria bassiana, pyrethrins and spinosad) were tested against the European grapevine moth Lobesia botrana. Trials were carried out against the second larval generation in two vineyards located in Tuscany and Veneto regions, from 2011 to 2013. In another trial the impact of two predators (Cryptolaemus montrouzieri and Nephus includens) on Planococcus ficus populations was assessed in an experimental vineyard. A completely randomized design was adopted to compare experimental treatments with an untreated control, sometimes with a reference synthetic insecticide. Regarding the control of L. botrana, trials stressed the high performance of spinosad whereas B. thuringiensis gave satisfactory results in Veneto only. The remaining insecticides were less effective. Side-effects of natural insecticides were evaluated. Leafhoppers (mainly Empoasca vitis and Zygina rhamni) were commonly recorded in the vineyard located in Veneto. They were sometimes more abundant in spinosad and pyrethrins treated plots. On the other hand, spinosad and pyrethrins reduced significantly predatory mite populations compared to other treatments. Regarding the control of P. ficus, the release of C. montrouzieri gave the best results. The effect of coccinellid releases was significantly higher than that of synthetic pesticides (spirotetramat). Implications for IPM are suggested.