Submitted to: Proceedings of the National Academy of Sciences
Publication Type: Peer reviewed journal
Publication Acceptance Date: 1/12/2006
Publication Date: 3/7/2006
Citation: Smith, M.A., Woodley, N.E., Janzen, D.H., Hallwachs, W., Hebert, D.N. 2006. DNA barcoding removes the generalists from an otherwise host-specific genus of tropical tachinid parasitoid flies. Proceedings of the National Academy of Sciences. 103:3657-3662. Interpretive Summary: Flies affect U. S. agriculture as pests causing millions of dollars in damage annually, or as beneficial predators and parasites. Tachinid flies, parasites of other insects, are the most important group of flies for biological control. This study detected 32 parasitic fly species using molecular DNA sequences or barcodes that were morphologically indistinguishable, and showed that most of the parasite species use a single host. This information has significant impact for biological control workers who must be certain of species identity before a control agent can be effectively used. This information will be of interest to scientists, biological control workers, and other action agencies concerned with insect pests.
Technical Abstract: Insect parasitoids are a major component of global biodiversity and play a key role in the population dynamics of their hosts. However, their identification is often difficult and they are suspected of having many cryptic species. Here we ask if the cytochrome oxidase 1 (CO1) DNA barcode can aid in species identification and discovery for the 20 morphospecies of Belvosia parasitoid flies (Diptera: Tachinidae) that have been reared from caterpillars in Area de Conservación Guanacaste (ACG), northwestern Costa Rica. Barcoding not only discriminates among all of the 17 host-specific morphospecies of ACG Belvosia, but it also raises the likely species count to 32 by finding that each of the three apparently generalist morphospecies are actually arrays of host-specific cryptic species. We discuss the implications of these results for conservation, host-parasite interactions and estimates of global species diversity.