New records of invasive aphids (Hemiptera: Aphididae) on garlic mustard in the USA

Abstract

Lipaphis alliariae Müller (Hemiptera: Aphididae) was identified from specimens collected in Lake County, Ohio, on the invasive garlic mustard, Alliaria petiolata (Bieb.) Cavara & Grande (Brassicaceae). The identification was performed on apterous viviparae using morphological and molecular data. Body color and shape of the cauda discriminated L. alliariae and L. pseudobrassicae Davis. Measurements of morphological characters of both species were similar, but they have distinct characters distinguishing them from L. erysimi Kaltenbach. Neighbor-joining analysis of cytochrome oxidase 1 (Cox1) barcoding indicated a close relationship of the aphids that feed on Brassicaceae, and the range of pair-wise distances for Cox1 barcoding of these species was 0.3–0.9%.