The population dynamics of Fiorinia fioriniae (Targioni) (Homoptera: Diaspididae) and factors affecting its seasonal abundance in Egypt.

Fiorinia fioriniae (Targioni) was observed attacking Callistemon lanceolatus at the Experimental Farm of the Agricultural Research Station and Ruscus hypoglossum at Antoniades park in Alexandria Governorate; Egypt. The infestation rate on Ruscus hypoglossum, reached its maximum (98.0%) during autumn months, while the minimum rate 68.3%, was recorded during summer months. The fluctuating population density of F. fioriniae showed three distinct peaks. The first peak of 731.0 individuals/10 branches was recorded in October 1998, the second (734.1) in December 1998, and the third, (506.9) in April 1999. The highest number of counted insects (1991.1/plant) was observed during the autumn season, followed by winter (1467.9), spring (978.2) seasons and the least number (271.6/plant) was recorded in summer. On the contrary, the highest rate of infestation by the immature stages was recorded during the winter season, followed by spring, summer and autumn seasons (42.8, 29, 24.6 and 21.9%) of the total counted insects, respectively. The scale insect has been parasitized with the aphelinid species Encarsia citrina (Aphelinidae) with a maximum rate of 28.1 of the total count during August. The statistical analysis was performed for determining the relationship between the prevailing weather factors of daily mean temperature, daily relative humidity, wind speed and day-light in one hand and the population activity of F. fioriniae on R. hypoglossum plants on the other hand.