Background: Cacopsylla melanoneura (Förster) is a vector of Candidatus Phytoplasma mali, the causal agent of one of the most serious diseases in European apple orchards, apple proliferation (AP). The aim of this study was to evaluate the toxicity of five insecticides from different chemical groups (carbamates, chitin inhibitors, insect growth regulators, organophosphates and pyrethroids) towards overwintered adults and young stages of C. melanoneura under semi-field conditions.
Results: The organophosphate chlorpyrifos and the pyrethroid etofenprox caused higher mortality of overwintered adults than diflubenzuron, fenoxycarb and abamectin, with mortality values exceeding 90%. All the pesticides tested reduced the number of progeny per female and, except for abamectin, were highly effective against young stages, with a long-lasting effect.
Conclusion: An integrated management of the vector is currently required to prevent the spread of AP. The reference insecticides, chlorpyrifos and etofenprox, have a strong toxicity and persistence against all stages of the vector. In apple orchard IPM programmes, the chitin inhibitors and the insect growth regulators could be part of an alternative and more sustainable strategy for the control of C. melanoneura owing to their effectiveness against immature stages.