ARS | Publication request: Mortality factors affecting Bemisia tabaci populations on cotton in the Cukurova plain, Turkey.

Submitted to: Journal of Applied Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 13, 2008
Publication Date: April 20, 2009
Citation: Karut, K., Naranjo, S.E. 2009. Mortality factors affecting Bemisia tabaci populations on cotton in the Cukurova plain, Turkey.. Journal of Applied Entomology. 133 pp 367-374

Interpretive Summary: The sweetpotato whitefly is a worldwide pest of many agricultural and horticultural crops. In cotton is can reduce yield through feeding on plant sap and contaminate cotton lint my honeydew excretion. Improved management systems for this pest in cotton will require a better understanding of the factors impacting its population dynamics. Cohort-based partial life tables were constructed to determine the source and rates of mortality factors affecting sweetpotato whitefly on cotton in the Çukurova plain of Adana, Turkey. Mortality factors were recorded as due to predation, parasitism, missing and unknown for five developmental stages. Across 20 generations, the highest median rate of marginal mortality pooled over all stages was due to predation; however, the key factor was determined to be parasitism. The greatest amount of immature mortality occurred during the fourth nymphal stadium and mortality during this stage was also most predictive of variation in total mortality. Pooled over all developmental stages, the highest rates of irreplaceable mortality were associated with parasitism (median: 0.092), followed by the predation (0.085), missing (0.034) and unknown (0.020). Results suggest that conservation of natural enemies, particularly parasitoids, may provide for more sustainable management of whitefly on cotton in the Çukurova plain of Turkey.

Technical Abstract: Cohort-based partial life tables were constructed to determine the source and rates of mortality factors affecting Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae) on cotton in the Çukurova plain of Adana, located in eastern Mediterranean region of Turkey. Mortality factors were recorded as due to predation, parasitism, missing and unknown for five developmental stages. Across 20 generations, the highest median rate of marginal mortality pooled over all stages was attributed to predation; however, the key factor was determined to be parasitism based on graphical and regression-based comparison of individual factor k-values to total generational mortality. The greatest amount of immature mortality occurred during the fourth nymphal stadium and mortality during this stage was also most predictive of variation in total mortality. Pooled over all developmental stages, the highest rates of irreplaceable mortality were associated with parasitism (median: 0.092), followed by the predation (0.085), missing (0.034) and unknown (0.020). Results suggest that conservation of natural enemies, particularly parasitoids, may provide for more sustainable management of B. tabaci on cotton in the Çukurova plain of Turkey.