Prey consumption and fecundity of Phytoseiulus persimilis athias-henriot fed on different stages and densities of Tetranychus urticae koch (acari : phytoseiidae : tetranychidae)‎ under laboratory conditions

Abstract EN

The effect of different prey densities and prey stages of Tetranychus urticae onfeeding capacity and fecundity of Phytoseiulus persimilis adult females was studied on leaf discs ofeggplant, Solanum melongena L.

(Black Baladi cultivar) during ten days under laboratory consistentconditions of 25 ± 2°C and 65 ± 2% R.

H.

.

The following prey densities were tested: 5, 10, 15 and 20for the tested stages of prey (eggs, larvae, males and females).

It was found that all of the prey testedstages were eaten by P.

persimilis females.

The total average of devoured prey individuals perpredator female during ten days was significantly (P ≤ 0.05) affected by stage and density of theintroduced prey.

In all cases, number of preys consumed by predator was increased with increasingprey density.

P.

persimilis consumed more eggs and larvae than males and females of the prey.

Totalaverages of consumed T.

urticae eggs and larvae were 35.5, 23.7; 67, 40.1; 82.2, 54.0 and 118.8, 77.2at prey densities of 5, 10, 15 and 20, respectively.

The highest consumption was detected when thepredator fed on T.

urticae stages at a density of 20/prey.

Eggs laid by predator female were differedsignificantly (P ≤ 0.05) according to stage and density of the introduced preys during the experimentalperiod.

The greatest number of deposited eggs was observed when feeding on T.

urticae eggs followedby females at different prey densities.

Total averages of P.

persimilis eggs were 10.7, 19.4, 29.7 and32.7 eggs (for prey eggs) as well as 9.2, 13.4, 22.5 and 25.9 eggs (for prey females), at prey densitiesof 5, 10, 15 and 20, respectively.

Differences in total number of deposited eggs of P.

persimilis werenot significant (P ≤ 0.05) when the predator was provided with larvae, males and females at each of thetested densities of T.

urticae.

A positive and high significant correlation was found between densitiesof prey stages and each of feeding capacity and fecundity of the predator.

Daily number of depositedeggs was gradually increased to reach the highest value on the sixth day in most cases.

Thereafter, thedeposited eggs were decreased to the end of experiment.

The present study suggests the possibility ofutilization P.

persimilis as an ideal biocontrol agent to reduce T.

urticae populations on eggplants