Differential Gene Expression (DGE) analysis identifies genes whose expression levels change significantly between different biological conditions. In our study, we aim to compare gene expression in T. myopaeformis prior to and after infection of susceptible and resistant sugar beet genotypes; resistant log2 fold-change in gene expression, we identified T. myopaeformis genes that are upregulated or downregulated in response to how the pest responds to its infection of susceptible and resistant sugar beet genotypes, highlighting the insect’s ability to cope with the sugar beet’s defense mechanisms in resistant varieties and the vulnerability in susceptible ones.