Wing Morphometry Helps Diagnose Cryptic Species and Resurrect Mindarus pinicolus (Hemiptera: Aphididae)

Wing venation, two-dimensional and with easily recognized reference points at vein junctions, presents an opportunity for the development of automated insect identification. Using a suite of continuous characters, I investigated the use of wing morphometry for computerized insect identification of cryptic species of the aphid genus Mindarus. A priori groups were determined using cytochrome oxidase 1 DNA barcodes. Discriminant function analysis of 24 wing measurements consistently grouped individuals of unknown taxonomic affinity with the correct a priori groups. The results suggest that diagnostic signal is present in wing morphometry, but the signal is considerably stronger with the addition of morphometry from other aphid appendages, namely, 10 leg and antennal segments. Almost all Mindarus collected in eastern North America have been determined as the balsam twig aphid, Mindarus abietinus Koch (Hemiptera: Aphididae), but molecular diagnostics reveals that the Palearctic species is not present in the Western Hemisphere. Schizoneura pinicola Thomas has been considered a North American synonym of M. abietinus. Morphometric discriminant function analysis suggests that the Abies-feeding eastern North American population is M. pinicolus. The species is here reinstated with a new combination and redescribed.