Submitted to: Journal of Agriculture of the University of Puerto Rico
Publication Type: Peer reviewed journal
Publication Acceptance Date: 6/10/2004
Publication Date: 4/1/2005
Citation: Pantoja, A., Ciomperlik, M., Wiscovitch, L., Gabriel, N., Vazquez, P., Robles, W. 2005. Evaluation of the establishment and distribution of exotic biological control agents of silverleaf whitefly in Puerto Rico. Journal of Agriculture of the University of Puerto Rico. Interpretive Summary: Silverleaf whitefly Bemisia argentifolii is a key pest insect of vegetables, field crops, and ornamental crops. Growers had limited success combating silverleaf whitefly through intensive use of broad-spectrum insecticides, additionally chemical control is not a viable option for most Caribbean farmers because of low prices combined with the high costs of products and spray equipment, not to mention lack of expertise in handling toxic insecticides. Biological control of this pest will function where broad-spectrum insecticides are absent and habitat diversity provides a continuous source to maintain natural enemy populations. In efforts to combat whitefly losses, a biological control program was cooperatively implemented by PPQ and the University of Puerto Rico to control silverleaf whitefly. The biological control program included both classical and augmentative approaches. Reconciliation of data records, indicating the initial release and the recovery site, reveals that exotic parasitoids can be recovered three years after the initial liberation. The data indicates that the exotic parasitoids have become established and are regulating whitefly populations. The savings associated with the reduction of insecticide use by augmenting natural enemies is estimated to exceed $1,200 /acre. The establishment of the exotic parasitoids, has benefited small farmers who produce tomatoes for the local market. These studies lead to a better understanding of B. tabaci parasitoids and their role in biological control programs.
Technical Abstract: Abstract The establishment and distribution of exotic biological control agents of the silverleaf whitefly in Puerto Rico was evaluated. Five hundred and twenty nine parasitoids were recovered from ninety-nine sites. Encarcia spp. represents over ninety percent of the total samples profiled, whereas Eretmocerus spp. represents only nine percent. The species of Eretmocerus haytii, from Pakistan, represents 56% of the total of that genus, followed by Er. mundus from Spain. An Encarcia species from Pakistan was the most abundant, representing twenty five percent of the total number of specimens from that group and twenty-tree percent of the total number of specimens recovered during the study. Unfortunately this is still an unidentified species. Five unidentified, and probably undescribed, species from Puerto Rico were detected during the study. Two of the local species represents about twenty percent of the total number of specimens profiled.