False codling moth, Thaumatotibia leucotreta (Meyrick, 1913) (Lepidoptera: Tortricidae), is an important pest on citrus in South Africa. Several new insecticides were screened for their potential negative impacts on T. leucotreta's reproduction through topical insecticide applications and detached fruit bioassays. Detached fruit bioassays showed that the registered standard concentration of Delegate^® 20 g/1001 and DPX-HGW86 35 ml/1001 caused females to oviposit significantly fewer eggs (P = 0.0016) than the controls. The same was found for the registered concentration of Coragen^®(P < 0.0001). Topical insecticide trials showed that only concentrations of Coragen^®, at the registered field rate and above had an effect on the moths’ reproductive output (P <0.0001). Alsystin^® and Meothrin™, which were used as industry standards, did not negatively affect the reproductive output of the moths during topical or detached fruit bioassay trials. This study helps to better understand the importance of the application mode, i.e. directly on moths or fruit and implies secondary benefits to some insecticide applications.