Citrus leafminer (CLM), Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae), is an important pest of citrus and related Rutaceae and ornamental plants almost worldwide. Pesticides are considered an essential, effective, and efficient control tool for leafminer. This study was designed to assess the effectiveness of two novel pesticides, thiamethoxam (0.25 g L−1) and acetamiprid (0.25 ml L−1) against citrus leafminer larvae. Two laboratory bioassays, leaf-dip bioassay (LDB) and topical bioassay (TB) were used to evaluate the efficiency of tested pesticides. Results conducted that thiamethoxam was more potent in citrus leafminer larvae than acetamiprid with percent mortality of (75%) and (100%) through leaf dip bioassay and topical bioassay, respectively after 24 hours of application. On the other hand, acetamiprid was also effective to control CLM with a percent of mortality up to 58.3% and 91.6% after 24h of application by both bioassays LDB and TB, respectively. The median lethal time (LT50) values showed that the leaf-dip Bioassay of thiamethoxam pesticides was more successful than another method of application, and the other pesticide with value 2.605h.