Existence of solutions for an age-structured insect population model with a larval stage

摘要

In this paper we particularly draw attention to the existence of solutionswhich describe the maturation rates of an age-structured insect population model. Suchmodels commonly divide the population into immature and mature individuals. Immature individuals are defined as individuals of age less than some threshold age t, whileadults are individuals of age exceeding t. The model is represented by the nonlinearneutral differential equation with variable coefficients. The conditions, which guarantee that the population size tends to a nonnegative constant or nonconstant function arealso established.