The effect of both silica gel and nano silica gel were tested under laboratory, green house and field conditions. Results show that , the LC50s of the target insect pests Tuta absoluta under laboratory conditions give, 44, 58, 99, 121, 142, 153 and 155 ppm for Newly hatched larvae, 1st larval instars, 2nd larval instars, 3rd larval instars, 4th larval instars, Adult males and Adult females respectively after treated with silica gel. The LC50s of the target insect pests T. absoluta which give, 18, 22, 30, 33, 41,46 and 49 ppm for Newly hatched larvae, 1st larval instars, 2nd larval instars, 3rd larval instars, 4th larval instars, adult males and adult females respectively after treated with Nano silica gel . Under green house conditions the means number of infestations show, that, after 20 days of application the means number of infestations record 10.0±6.1, 3.1±4.2 after treated with silica gel and nano- silica gel as compared to 29.2±4.7 Individuals in the control. After 50 days of application the means number for the corresponding treatments give 20±3.1, 7.0±1.1 as compared to 68±5.5 individuals in the control . At the end of the experiments after120 days, silica gel and Nano silica gel application recorded that, the individuals number 59±2.9, 12.0±4.1 and 99±9.9 individuals in the control. Under field conditions after the harvest time , the crop of tomatoes weight recorded, 2731± 26.60, 3331± 39.80 Kg/ feddan as compared to 2224± 41.81 Kg/feddan in Fayoum governorate. In Tanta governorate, the weight of tomato recorded 1991± 16.40 , 3451± 16.70 as compared to2030± 56.60 kg/ feddan.