Schutze M K, Jessup A, Clarke A R
Discipline of Biogeosciences, Queensland University of Technology, Brisbane 4000, Queensland, Australia.
Bull Entomol Res. 2012 Feb;102(1):103-11. doi: 10.1017/S0007485311000423. Epub 2011 Aug 26.
Four morphologically cryptic species of the Bactrocera dorsalis fruit fly complex (B. dorsalis s.s., B. papayae, B. carambolae and B. philippinensis) are serious agricultural pests. As they are difficult to diagnose using traditional taxonomic techniques, we examined the potential for geometric morphometric analysis of wing size and shape to discriminate between them. Fifteen wing landmarks generated size and shape data for 245 specimens for subsequent comparisons among three geographically distinct samples of each species. Intraspecific wing size was significantly different within samples of B. carambolae and B. dorsalis s.s. but not within samples of B. papayae or B. philippinensis. Although B. papayae had the smallest wings (average centroid size=6.002 mm±0.061 SE) and B. dorsalis s.s. the largest (6.349 mm±0.066 SE), interspecific wing size comparisons were generally non-informative and incapable of discriminating species. Contrary to the wing size data, canonical variate analysis based on wing shape data discriminated all species with a relatively high degree of accuracy; individuals were correctly reassigned to their respective species on average 93.27% of the time. A single sample group of B. carambolae from locality 'TN Malaysia' was the only sample to be considerably different from its conspecific groups with regards to both wing size and wing shape. This sample was subsequently deemed to have been originally misidentified and likely represents an undescribed species. We demonstrate that geometric morphometric techniques analysing wing shape represent a promising approach for discriminating between morphologically cryptic taxa of the B. dorsalis species complex.
桔小实蝇复合种（桔小实蝇指名亚种、番木瓜实蝇、杨桃实蝇和菲律宾实蝇）中的四个形态学上难以区分的物种是严重的农业害虫。由于使用传统分类技术难以对它们进行诊断，我们研究了通过对翅的大小和形状进行几何形态测量分析来区分它们的可能性。15个翅地标点生成了245个标本的大小和形状数据，以便随后对每个物种的三个地理上不同的样本进行比较。在杨桃实蝇和桔小实蝇指名亚种的样本中，种内翅大小存在显著差异，但在番木瓜实蝇或菲律宾实蝇的样本中则没有。尽管番木瓜实蝇的翅最小（平均质心大小 = 6.002毫米±0.061标准误），桔小实蝇指名亚种的翅最大（6.349毫米±0.066标准误），但种间翅大小比较通常没有信息量，无法区分物种。与翅大小数据相反，基于翅形状数据的典型变量分析能够以相对较高的准确度区分所有物种；个体被正确重新归类到各自物种的平均时间为93.27%。来自“马来西亚丁加奴”地区的一组杨桃实蝇样本是唯一在翅大小和翅形状方面与其同种群体有显著差异的样本。该样本随后被认为最初被误识别，可能代表一个未描述的物种。我们证明，分析翅形状的几何形态测量技术是区分桔小实蝇复合种中形态学上难以区分的分类单元的一种有前景的方法。
