Natural Enemies, Mediated by Landscape and Weather Conditions, Shape Response of the Sorghum Agroecosystem of North America to the Invasive Aphid Melanaphis sorghi

The sorghum ( Sorghum bicolor [L.]) agroecosystem of North America provided an opportunity to evaluate response invading insect herbivore, Melanaphis sorghi (Theobald) (sorghum aphid) (previously published as sacchari Zehntner) (Hemiptera: Aphididae) onto a widely planted crop that experiences range agro-landscape and weather conditions. Initial risk assessments after M. 's invasion in the mid-2010s forecasts expansion annual migration, which were based on aphid life history, extent cultivation susceptibility , (aphid-plant-weather [APW] scenario). A more comprehensive assessment proposed here brings top-down forces -natural enemy interactions forefront mediated by conditions (aphid-enemy/landscape-weather [AE/LW] hypothesis regional differences aphids natural enemies sensitivity was tested using empirical data insect, landscape, across 5 years four regions (two U.S. Great Plains [South GP GP], one farther south (South), southeast E]). Natural widespread with two parasitoids coccinellid species common regions, but variation abundance detected. AE/LW scenario accounted for activity highest South region, functioned well conditions, accompanied average low (~23 per leaf). Positive correlations enemy- also occurred region where (~20 leaf), selected appeared be landscape composition. E (~136 aphids/leaf) influenced weather. suited, essential assessing scale, sets stage further modeling generate estimates degree influence under varying considered scenario. Broadly, these findings are relevant understanding resilience recommending supportive management inputs invasions context varied environmental