A simple method of estimating accumulated thermal units was adopted; utilizing daily mean temperature. The threshold rates of devel­opment of citrus leaf miner stages viz. egg, larva, pre-pupa, pupa and adult on 4 constant temperatures (15. 20, 25 and 30C) were estimat­ed. The bio feature parameters decreased with the increase in the corre­sponding temperature. The total life span duration varied greatly be­tween 127.1, 53.7, 24.7 and 22.2 days at 15, 20, 25 and 30C, respectively. The target instars reared in both laboratory temperature (26.3-±-2C) and green house temperature (24.1±3°C) showed that the total life span was 25.8 and 27.1 days, respectively. The estimated zero figures of development for eggs, larvae, pre pupae, pupae and adults were 7.5, 12.6, 10.7, 12.7, and 11.90, respectively with general mean 11.1°C. The accumulated thermal units needed for completing one gener­ation was 398.29 DD units.