<b>Populational fluctuation and generation prediction of <em>Grapholita molesta</em> (Busck, 1916) (Lepidoptera: Tortricidae) in peach, <em>Prunus persic</em>a (Linnaeus) Batsch</b> - DOI: 10.4025/actasciagron.v28i3.963

Abstract

The oriental fruit moth, Grapholita molesta (Busck, 1916), is spread around the world and is considered an important pest on peach, Prunus persica (Linnaeus) Batsch. This work was carried out at a commercial peach orchard located in Taiúva, State of São Paulo, Brazil, from 1997 to 2003, aiming to obtain the population fluctuation of adults of G. molesta and to relate it to meteorological factors. This study also aimed to determine an appropriate time as a biofix to predict the occurrence of generations of G. molesta using a degree-day model. Adults of the oriental fruit moth and insect predators were sampled by plastic bottle traps with peach juice and yellow sticky traps, respectively. The influence of abiotic and biotic factors was evaluated by simple correlation analysis. The highest population peaks of G. molesta were observed in May, July and October. The correlations suggest that low environmental humidity might have been a factor of mortality to G. molesta. A negative impact on natural enemies caused by high number of insecticide applications may have been responsible for the high pest density from 1998 to 1999. The date that peach trees developed vegetative and flower buds appeared to be suitable to initiate the degree-day accumulation to predict generations of G. molesta. These results should help the implementation of programs based on predicting population peaks of adults aiming insecticide application. Before field implementation, final validation of the degree-day model is required in multiple locations.