SOME BIOLOGICAL AND ECOLOGICAL ASPECTS OF EUZOPHERA OSSEATELLA ON CERTAIN SOLANACEAE PLANTS IN EGYPT

Abstract

Some biological and ecological aspects were studied on the eggplant stem borer, Euzophera osseatella Treit. (Lepidoptera: Pyralidae) under laboratory and controlled conditions. 1. Biological aspects of E. osseatella: 1.1. Life table parameters: The egg, larval and pupal stages of E. osseatella lasted 5.8, 33.2 and 12.9 days, respectively at 27±1℃ and 65±5 % R.H. The mortality percentage in the corresponding stages reached 14, 37 and 13%. The sex ratio in E. osseatella was in favour of females (1:1.1). The preoviposition, oviposition and postoviposition periods averaged 1.8, 3.1 and 1.2 days, respectively. The daily and total numbers of eggs/female of E. osseatella were 46.6 and 147.2, respectively. The male and female lived 4.4 and 6.2 days, respectively. The mean generation time (T) of E. osseatella averaged 54.22 days. The net reproductive rate (Ro), the intrinsic rate of increase (rm) and the finite rate of increase (exp.rm/ λ) were 28.09, 0.062 and 1.063, respectively. The generation doubling time (Dt) of E. osseatella reached 14.01 days. The fecundity curve (Mx) showed three peaks of 14.14, 20.14 and 12.32 female progeny/female/day at the female age (X) of 50.5, 61.5 and 63.5 days, respectively. The survival curve (Lx) of the insect revealed that most death of females occurred after an extended oviposition period to compensate failure of most immature stages to reach maturity (64%). The life table is an important tool for understanding the population dynamics of the insect pest. It serves as a framework for organizing dates of the mortality and natality. It calculates simply brief statistics such as the life expectancy of beneficial insects, which can be used in biological control programs. It is very useful for knowing the time and reasons of the highest mortality within the pest population. It enables us to apply