Population dynamics of Saissetia oleae. Ι. Assessments of ροpulation and mortality

Abstract

The population dynamics of Saissetia oleae (Oliv.) (Homoptera-Coccidae) was studied in Corfu during five successive yearly generations (1981)(1982)(1983)(1984)(1985)(1986). Successive estimates of the population of S. oleae were obtained within each of the five yearly generations and survivorship curves were constructed showing the progressive reduction of the living population within each generation and population changes from generation to generation. The calculated mortality rates indicate that the population of S. oleae .suffers heavy mortality. The major mortality factors were high temperatures during summer, the action of predators, particularly during spring. and mortality of crawlers during summer. Overall survival rate was very low and corresponded to total generation mortality that ranged from 99.693% to 99.987%. It is assumed that variation in the action of mortality factors cause considerable fluctuations of the S. oleae population.

Population dynamics of Saissetia oleae. II. Life-tables and key-factor analysis

“…Study sites and sampling procedure The study sites and sampling techniques were described in the previous paper (Stratopoulou and Kapatos 1990). Briefly, the study was conducted at 7 experimental sites, each of 70-150 olive trees, distributed all over the island.…”