Identification of the Bactrocera dorsalis Complex (Diptera: Tephritidae) by PCR-RFLP AnalysisIII. Discrimination between B. philippinensis and B. occipitalis

摘要

Applicability of the polymerase chain reaction fragment length polymorphism (PCR-RFLP) for discrimination between two Philippine species of fruit flies, Bactrocera philippinensis and B. occipitalis, was examined. To determine restriction enzymes thatcan be used in PCR-RFLP analysis, a 0.48 kb-long portion of the PCR amplified 16S rRNA gene of the mitochondrial DNA was sequenced. Comparison of the sequences suggested that the two species can be differentiated by electrophoresis patterns of the DNA fragment treated by the restriction enzyme HinfI. In order to confirm the usefulness of the banding patterns for the species discrimination, relationships between banding patterns and previously proposed morphological diagnostic characters, such as lengthsof male aedeagus, female aculeus, and CuA1 vein, were examined using a total of 130 individuals collected in the field and at quarantine inspection sitxes. In the case of male adults, PCR-RFLP patterns agreed very well with the result of species discrimination based on the aedeagus length. PCR-RFLP analyses also clearly divided female adults into two different groups of individuals. Such a grouping roughly agreed with that based on the aculeus/CuA1 value. However, because there were several individualsthat showed intermediate values between the two groups, we could not confirm the accuracy of the species discrimination of female adults based on PCR-RFLP analyses. To do this, further analyses using mtDNA, nuclear DNA, and other morphological markers are needed.