The African sugarcane stalk borer, Eldana saccharina, is reported to show high levels of genetic differentiation in its indigenous range. This evoked the hypothesis that one of its biological control agents, Sturmiopsis parasitica, might have undergone genetic differentiation in response to the differentiation in its host. To confirm this hypothesis, mitochondrial DNA sequences in cytochrome oxidase I were sequenced. Phylogenetic analysis of the sequences using maximum parsimony clustered the specimens into two groups (northern and southern). Approximately 500 bp were obtained from 15 specimens of S. parasitica. Sequence analysis revealed the presence of genetic divergence between S. parasitica specimens ranging from 0% (within the Benin specimens) to 5.3% (between the northern and southern groups). The genetic divergence observed suggests the presence of intraspecific polymorphism in S. parasitica.