Cold hardiness of Corythucha marmorata (Hemiptera: Tingidae) on the functional crop Helianthus tuberosus.

The invasive phytophagous lace bug, Corythucha marmorata, threatens the functional food crop Helianthus tuberosus, but its overwintering ecology on this plant is poorly understood. This study evaluated the cold hardiness of C. marmorata at various life stages, focusing on the differences between female and male adults. C. marmorata overwinter as adults on H. tuberosus, based on a four-year winter field investigation. The supercooling and equilibrium freezing points of C. marmorata decline with development. Female adults showed the greatest supercooling capacity. The lower lethal temperature (female - 15 °C, male - 16 °C) is above the supercooling point (- 26 °C). The low temperature exposure mortality of C. marmorata female and male adults exhibited different regularities. We conclude that C. marmorata belongs to chill susceptible insects. October to February is the most recommended period for C. marmorata control by harvesting H. tuberosus. Weed removal, such as Erigeron bonariensis, Erigeron canadensis, and Ambrosia trifida, is an early control measure. These results enhance our understanding of C. marmorata's cold tolerance and inform targeted pest management strategies for H. tuberosus crops.