Molecular markers for characterization and identification of European corn borer, Ostrinia nubilalis (Hubner) (Lepidoptera: Crambidae) and screwworm, Cochliomyia hominivorax (Coquerel) (Diptera: Calliphoridae)

AFLP analysis in three European corn borer (ECB) populations from Europe and the United States using 12 primer pairs revealed high variability within populations and low genetic similarity (54%) between populations. Cluster analysis correctly grouped (>90% bootstrap support) the populations based on geographic origin and the E2+M6 primer pair differentiated populations from Europe and the United States. Screening 8 populations of ECB from the United States with the E2+M6 primer pair failed to resolve the pheromone strains. However, the univoltine ecotype could be differentiated from the bivoltine and multivoltine ecotypes. ECB samples showed high within population variability and variable similarity levels between populations. Clustering of samples from different geographical regions suggests that gene flow does occur between populations.; Analysis of four C. hominivorax populations using 80 RAPD primers generated 10 potential diagnostic bands with 5 primers that could be used for identifying general geographical origin of populations. Cluster analysis of the RAPD data also revealed the applicability of this technique for population discrimination. A 270 by diagnostic band was successfully cloned and sequenced to generate. STS (sequence tagged sites) markers. AFLP analysis using 10 primer pairs revealed very low (16%) similarity between C. macellaria and C. hominivorax. The within population similarity levels in C. macellaria (92%) and C. hominivorax (68%) suggests more population substructure and genetic variability in C. hominvorax. Additionally, diagnostic bands for inter-specific discrimination (22 bands in C. macellaria and 10 bands in C. hominivorax) and intra-specific identification (13 bands) were identified by AFLP fingerprinting. AFLP analysis in ten C. hominivorax strains revealed a higher level of genetic similarity within populations than between populations. All 10 strains grouped at the 58% similarity level. At the 85% similarity level, 7 clusters (mutant strains) were resolved, and at the 72% similarity level 10 clusters representing 10 strains were resolved. The founder effects and the number of generations each strain was in colony could explain higher similarity detected in the mutant strains than in the wild populations.