Abstract: This paper deals with the bionomics of Micromelopha troglodyta.The pest has 2 generations a year and overwinters in pupa in the fallen leaves.In the food lack condition,the last instar larvae is compelled to pupate in advance,themass of the pupa ismuch lighter than that of normal pupa.If themass of the pupa is below 90mg,it can not emerge.Themathematicalmodel between the probability of the female and the pupamass is Yi =-6.22+3.256 log Xi.Themathematicalmodel between amount of the female eggs and the pupamass is Yi′=-1 886.3+1 014.4 log Xi.Applying thesemathematicalmodels,we can forecast the population dynamics ofm.troglodyta.