Successful application of the baculovirus product Madex for control of Cydia pomonella (L.) in Bulgaria

The codling moth (CM), Cydia pomonella (L.), causes heavy damage in Bulgarian apple orchards. Conventionally treated orchards, were monitored in this study. In spite of numerous chemical treatments, these orchards showed increasing flight densities of CM moths, growing populations of hibernating larvae and rising fruit damage rates. Thus, the control of CM by conventional spraying programmes became ineffective, apparently due to the development of resistance to insecticides. Products based on the Cydia pomonella granulosis virus (CpGV), such as Madex®, may provide alternative control tools that can be applied with other approaches, for a sustainable control strategy. The trials were carried out in Central-South and South-East Bulgaria, in 2006-2010. Four treatments of Madex® against the first generation, and six treatments against the second generation kept the fruit damage and population density of CM at a low level. Based on the obtained results, different control strategies have been suggested, depending on the initial CM pressure in a particular orchard. Madex® may be a promising alternative to traditional programmes of CM control. Its dose, however, should be adjusted to the initial CM population density. Also, at a high or moderate CM population density Madex® applications should be combined with MD to avoid resistance of CM to granulovirus. At the peak of CM hatching, additional chemical treatments may be sometimes necessary. Such treatments include using insecticides which are still effective against CM.