<p>Bagging banana fruits can be develop as a control to protect the fruits from Nacoleia octasema. The objective of this research was to determine the effect and relation of the banana fruit bagging time on N. octasema. This research was conducted in Tlogo Orchard, Delik Village, Tuntang District, Salatiga, Central Java from September-November 2018. This research used purposive sampling with 3 banana cultivars and 4 treatment. The observation variable of this research was the incidence of attacks. The results showed that there was an effect on the banana fruit bagging time against the incidence of pest attacks. The average incidence attack showed that the unbagged banana fruits had the biggest attacks. In addition, there was a positive relationship between the banana fruit bagging time and cultivars on the incidence of attacks. The older a banana bagged, the greater incidence of pest attacks. Kepok had the biggest incidence of attacks compared to the other cultivars.</p>