Entomopathogenic nematodes for biological control of codling moth

Entomopathogenic nematodes are often found naturally infecting codling moth larvae. The effect of an autumn treatment with S. feltiae on the fruit damage in the following summer was evaluated by treating 4 different apple orchards in October 2004 and 2005 at application rates of 3.75; 2 and 1.5 billion nematodes in 4000 l / ha. In three of the treated orchards, one treated with 3.75x109 nematodes/ha the other two treated with 2e9 nematode/ha, reduction in fruit damage was around 50%. In the most heavily infested orchard, which was treated with 1.5x109 nematode/ha only 33 % reduction in fruit damage was achieved. Compared to previous studies, this was the first assessing the effect on the fruit damage in the summer following the treatment rather than assessing the mortality of sentinel larvae fixed to the treated tree trunks