A comparison of three Encarsia species as controlling agentsfor Bemisia tabaci in greenhouses

Abstract: The study constitutes part of an effort to locate potentially efficient agents forbiological control against the whitefly Bemisia tabaci. Three parasitoid species, Encarsia inaron,E. lutea and E. sophia, which attack B. tabaci under natural conditions were studiedcomparatively in order to evaluate the most suitable species for use as a biological control agentagainst Bemisia tabaci in greenhouses. The tested parameters were: developmental durations,longevity and oviposition characteristics. All three species lived ca. 20 days each and the twoformer ones developed to adulthood within ca. 14 days and E. lutea, within 15. The differencesbetween oviposition rates were not significant (66 ± 36.27, 32.84 ± 26.19 and 42.73 ± 21.74average and standard deviation of the mean respectively for E. inaron, E. lutea and E. sophia,respectively). Encarsia inaron had the highest percentage of females that lived longest whereasE. lutea had a higher semelparity. Our findings failed to reveal the superiority of one species overthe others as candidates for the intended biological control. Additional parameters, including theircompetitive behavior and compatibility with other natural enemies in the greenhouse, should thusbe considered.