Effects of Temperature and Host Plant on Hedgehog Grain Aphid, Sipha maydis Demographics

SIMPLE SUMMARY: The hedgehog grain aphid (HGA) is a pest that affects cereal crops worldwide and was first observed in the United States in 2007. To understand how this aphid spreads and becomes damaging, it is essential to study how temperature and the host plant affect its development and reproduction. In this study, we found that temperatures between 20 °C and 25 °C are best for HGA survival and reproduction, while temperatures below 10 °C and above 35 °C do not allow for survival. This study revealed that HGA can survive on wheat, millet, and three cultivars of sorghum, including those resistant to the sorghum aphid. Together, these results help us predict HGA populations by identifying host plants in cereal crops and documenting how temperature affects these populations. ABSTRACT: The hedgehog grain aphid (HGA), Sipha maydis Passerini (Hemiptera: Aphididae), is a cereal pest in many regions of the world. It was first documented in the United States in 2007, and it has a range that appears to be expanding. Understanding the effects of temperature and the host plant on HGA development, survival, and reproduction is crucial for understanding its population dynamics, potential distribution, and management strategies. In this study, we investigated the effects of different temperatures and host plants on the demographic parameters of HGA and determined the supercooling point (SCP) for their first instars, apterous adults, and winged adults. Our findings revealed that temperatures between 20 °C and 25 °C were optimal for HGA development and reproduction, with parthenogenetic females producing approximately 60 offspring in their lifetimes. However, HGA development was hindered below 10 °C and above 35 °C. The SCP for HGA was similar (mean ± S.E.: −16.280 ± 0.532 °C) among nymphs, apterous adults, and winged adults. We compared the HGA demographics with the demographics of the sorghum aphid (SA), Melanaphis sorghi (Theobald, 1904), on wheat, millet, and three cultivars of sorghum under a constant temperature. The HGA completed its life cycle on all the tested host plants with a similar reproduction, demonstrating a lack of resistance to HGA by a sorghum that is resistant to SA. By expanding our knowledge of host plant- and temperature-dependent development, reproduction, and mortality in S. maydis, we can better predict and manage future HGA populations in small grain crops.