Distribution, Host Range Expansion, and Genetic Diversity of Hedgehog Grain Aphid in the Central United States

Hedgehog grain aphid, Sipha maydis Passerini, is a key pest of many cereal crops and pasture grasses around the world. Because of potential to damage crops, wide range of host plants, and occurrence in varying climatic conditions, frequent assessments of distribution of hedgehog grain aphid are needed with documentation of hosts and assessment of genetic differentiation. Fields were Wyoming. Surveys did not detect hedgehog grain aphid in New Mexico, Oklahoma, Texas, and Wyoming and only found it on wild grasses in Colorado and Utah. DNA was isolated from hedgehog grain aphid samples collected between 2016 and 2022 from 11 grass hosts in Colorado, New Mexico, and Utah. The 18S rDNA and translation elongation factor 1-alpha gene fragments were amplified and sequenced from each sample and no genetic variation was detected. Based on field surveys and genetic analysis, hedgehog grain aphid seems established in limited clonal populations on various wild grasses. At present, hedgehog grain aphid is not a significant threat to small grain crops in the United States, but continued monitoring is necessary because of its broad host range and potential for economic damage, as observed in Argentina.