Forensic entomology is a science that enlightens post-mortem interval, body relocations, type and dose of narcotics that cause death via biological features of insects. The entomological fauna of the crime scene should be known in order to do all these studies. Different methods are applied on the purpose of collecting insects in fauna studies. The most known method is the basic meat bait trap method. The blowflies, enter basic meat bait trap for feeding and laying eggs, can escape consequently the count of samples may be insufficient. It is examined in our study that the effects of chemical meat bait traps, which are prepared with thiamethoxam and basic meat bait traps on insects. Traps were hung at the trees 1,5m above the ground at 10m distances in the garden of Ankara University Forensic Sciences Institute at 8 a.m. on the first Monday of each month for eight months. Totally we collected 1894 species during the study period. Of all these species, 1787 (94,35%) were obtained from chemical meat bait traps and 107 (5,65%) were obtained from basic meat bait traps. The number of species collected from basic meat bait traps was considerably higher. The results of this study will help researchers to save time. In addition, it should be kept in mind that thiamethoxam is a poisonous substance. Laboratory accidents did not occur during our study.   Keywords: Basic meat bait trap, Chemical meat bait trap, Diptera, Fauna, Thiamethoxam