Morphometric study using wing image analysis for identification of the Bactrocera dorsalis complex (Diptera: Tephritidae)

Abstract

Eight species of the Bactrocera dorsalis complex ( Diptera: Tephritidae ) used in this study included B. dorsalis,B. arecae, B. carambolae, B. payena, B. propinqua, B. pyrifoliae, B. verbascifoliae, and three new species complexes are Species E, Species K and Species P. Bactrocera tau was used as an out-group. A total of 424 wings of the adults emerged from pupae collected from natural populations in Thailand were prepared for measurements. Morphometric analysis was made from measuring wing vein characters. The wing image is captured in digital format and go through digital image processing to calculate Euclidean distance of each wing vein. Discriminant and cluster analyses were used for dichotomy of classification processes. All 424 wing specimens were classified to species in terms of the percentage of "grouped" cases which yielded about 89.6% accurate identification compared with the formal description of these species. After clustering, the percentage of "grouped" cases yielded about 100.0%, 98.9%, 98.1%, 95.2 and 84.6% accurate identification between the B. dorsalis complex and B. tau; B. arecae and Species E; B. dorsalis and B. verbascifoliae; B. propinqua and B. pyrifoliae; and Species K and Species P, respectively. This method of numerical taxonomy may be useful for practical identification of other groups of agricultural pests.