INTRASPECIFIC DIVERSITY OF THE CASSAVA GREEN MITE MONONYCELLUS-PROGRESIVUS (ACARI, TETRANYCHIDAE) USING COMPARISONS OF MITOCHONDRIAL AND NUCLEAR RIBOSOMAL DNA-SEQUENCES AND CROSS-BREEDING

Intraspecific diversity in Cassava Green Mite Mononychellus progresivu s Doreste was examined using individuals collected in Benin and the Co ngo and in Columbia and Brazil. Comparisons were based on mitochondria l and ribosomal DNA sequences and the results of several cross-breedin g experiments. Sequence variation was examined in a total of 1139 base pairs (bp) constituting the ITS2 ribosomal DNA (805 bp) and a fragmen t of the Cytochrome Oxidase I (COI) gene (334 bp). Sequence divergence is low, ranging from 0% to 2.1% for COI and from 0% to 0.4% for ITS2. Inter-strain comparisons have shown that the two African populations appear to be identical. They were similar to the Colombian population while the Brazilian population was clearly different. The data support the hypothesis of a single introduction of the species in the two Afr ican populations. Crossing experiments have shown partial hybrid steri lity, suggesting a genetic incompatibility consistent with differences detected by sequence data. The results show the usefulness of molecul ar markers as a tool for determining taxonomic status and dispersion p aths in spider mites.