Abstract

COMPARATIVE RELATIONSHIP BETWEEN DEVELOPMENT TIME AND FECUNDITY AS A FUNDAMENTAL TOOL IN LIFE TABLES PARAMETERS OF PREVAILING STRAINS OF SPINY BOLLWORM EARIAS INSULANA (BOISD) IN FOUR GOVERNORATES (DELTA, EGYPT)

El-Bassouiny H. M.*, Mervat A. Kandil and Ashraf F. Ahmed

ABSTRACT

The present work conducted to study the relationship between the duration developing stages and fecundity necessary for estimated Life Table of the collected Earias insulana (Boisd.) from okra fields in four Governorates: Alexandria, Sharkia, Monefaia and Qaliobia to examine the mortality changes in the Social Security population over time in Governorates of Delta, Egypt . Results elucidated the existence of variation in sex ratio and developmental times of the spiny bollworm stages in the four Governorates. Sex ratio parameters were 5.9, 5.3, 4.6 and 4.2, the generation times was highly affected it was shortened up to 25.2 days in Monefaia strain and increased gradually till 27.0, 27.8 and 30.7days in Sharkia, Qaliobia and Alexandria strains, in respcet. In case of the collected strains from fields at Alexandria, Sharkia, Monefaia and Qaliobia, adults’ female longevities lasted 17.6. 16.3, 15.3 and 14.1 days/ females, the total average numbers of deposited eggs were 221.0, 207.0, 187.0 and 199.0 eggs/ female, with a daily average numbers of deposited eggs per four females strain comprised 18.57, 19.52, 18.5 and 21.39 eggs, respectively. Also, the resulted data showed that Sharkia had the highest percentage of egg hatchability (91%), followed by Alexandria (89%), Monefaia (80%) and Qaliobia (76%). life table was a basic tool for eradication of the surviving pest strains of the different investigated governorates. Eah of Sharkia and Alexandria, governorates strains were considered the best-tested strains in the most estimated life table parameters of E. insulana. The (RO) value of E. insulana was approximately nearly equal in Alexandria and Sharqia strains’ and amounted to 36.672 and 36.230 female daughter/female, and decreased in Qaliobia and Monefaia strains up to 33.856 and 29.541 female daughter/ female.

Keywords: Earias insulana, relationship, fecundity, developmental times, Life table, Sex ratio, hatchability.