The effect of different prey densities and prey stages of Tetranychus urticae on
feeding capacity and fecundity of Phytoseiulus persimilis adult females was studied on leaf discs of
eggplant, Solanum melongena L. (Black Baladi cultivar) during ten days under laboratory consistent
conditions of 25 ± 2°C and 65 ± 2% R.H.. The following prey densities were tested: 5, 10, 15 and 20
for the tested stages of prey (eggs, larvae, males and females). It was found that all of the prey tested
stages were eaten by P. persimilis females. The total average of devoured prey individuals per
predator female during ten days was significantly (P ≤ 0.05) affected by stage and density of the
introduced prey. In all cases, number of preys consumed by predator was increased with increasing
prey density. P. persimilis consumed more eggs and larvae than males and females of the prey. Total
averages of consumed T. urticae eggs and larvae were 35.5, 23.7; 67, 40.1; 82.2, 54.0 and 118.8, 77.2
at prey densities of 5, 10, 15 and 20, respectively. The highest consumption was detected when the
predator fed on T. urticae stages at a density of 20/prey. Eggs laid by predator female were differed
significantly (P ≤ 0.05) according to stage and density of the introduced preys during the experimental
period. The greatest number of deposited eggs was observed when feeding on T. urticae eggs followed
by females at different prey densities. Total averages of P. persimilis eggs were 10.7, 19.4, 29.7 and
32.7 eggs (for prey eggs) as well as 9.2, 13.4, 22.5 and 25.9 eggs (for prey females), at prey densities
of 5, 10, 15 and 20, respectively. Differences in total number of deposited eggs of P. persimilis were
not significant (P ≤ 0.05) when the predator was provided with larvae, males and females at each of the
tested densities of T. urticae. A positive and high significant correlation was found between densities
of prey stages and each of feeding capacity and fecundity of the predator. Daily number of deposited
eggs was gradually increased to reach the highest value on the sixth day in most cases. Thereafter, the
deposited eggs were decreased to the end of experiment. The present study suggests the possibility of
utilization P. persimilis as an ideal biocontrol agent to reduce T. urticae populations on eggplants