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Focussed searches were made across New Zealand between 2013 and 2016, for endemic aphids from the Schizaphis (Rhopalosiphina) genus, which is currently represented by two putative, undescribed species from the endemic host plants Aciphylla and Dracophyllum. Cytochrome c oxidase I (COI) gene sequences (48 in total) from the Schizaphis were analysed together with those from a broader collection of New Zealand endemic aphids that has been assembled since the year 2000. The bulk of the Schizaphis belonged to two clusters corresponding to the host plant genera. Two aphids from central North Island Dracophyllum represented a much diverged lineage without clear affiliations to other New Zealand Schizaphis. Inter-population variation in the New Zealand Schizaphis was high compared with that seen in international studies of Aphidinae and among populations of other endemic New Zealand Aphidina. Within Schizaphis from Dracophyllum, geography played an apparent role in genetic structuring, with populations from Taranaki (North Island) and especially Mt Lyford (South Island) being divergent from those on the South Island main divide. Two distinct lineages of Schizaphis, which co-occurred at some sites, were found on Aciphylla. Our sequence comparisons, including GMYC analyses, indicated up to five New Zealand Schizaphis lineages, and two newly discovered endemic Aphis species from the host plants Clematis and Hebe. [ABSTRACT FROM AUTHOR]

The cytochrome c oxidase subunit I (COI) gene of the mitochondrial DNA was sequenced in eight holocyclic monoecious aphids (Hemiptera: Aphididae) that occur on wheat, Triticum aestivum L.; barley, Hordeum vulgare L.; oat, Arena sativa L.: and sorghum, Sorghum bicolor (L.) Moench in the United States. The first 640 bp of the 5' end were considered as a DNA barcoding technique for species identification. DNA barcoding successfully differentiated Schizaphis graminum (Rondani), Diruaphis noxia (Kurdjumov), Diruaphis tritici (Gillette), Diruaphis frequens (Walker), Diruaphis mexicana (McVicar Baker), Sipha tiara (Forbes), Sipha elegans del Guercio, and Sitobion avenae (F.). In addition to the above-mentioned monoecious species, the common cereal aphids Rhopalosiphum padi (L.) and Rhopalosiphum maidis (Fitch) were included and successfully differentiated. DNA barcoding is a reliable alternative to traditional morphology in the identification of cereal aphids and their various life stages and morphs, including eggs. The application of DNA barcoding to aphid eggs found on grasses will be able to confirm whether D. noxia is now reproducing sexually in the United States after 20 yr of sexual reproduction. [ABSTRACT FROM AUTHOR]