Abstract : Specific mate recognition system (SMRS) described by Paterson is an important factor in species characterization. In this context, study of Lepidoptera species complex is interesting. In Kenya, genus Busseola is represented by three species. B. fusca is an interesting case of a practically complete shift from wild compartment to cultivated area whereas B. phaia and B. segeta are likely to be an example of host fidelity. B. phaia and B. segeta share their range with B. fusca, but are separated from each other by the Rift valley and host-plants. B. phaia and B. segeta are very close related by taxonomy criteria. We studied these taxa through chemical ecology and phylogenetic approaches. Genetic diversity observed in B. fusca populations is not correlated with SMRS variability. In B. phaia and B. segeta, the study of SMRS led to the characterization of the reproductive isolation components. The phylogenetic analysis combined with chemical ecology contributed to make different assumptions on the species status of B. phaia and B. segeta.