The red sunflower seed weevil, Smicronyx fulvus LeConte (Coleoptera: Curculionidae), is a primary seed‐feeding pest of cultivated sunflowers, Helianthus annuus L., in North America. Host plant resistance is one tool available to complement insecticide‐based management of S. fulvus. Artificial infestations of 30 adult weevils per head were used to determine whether variation for susceptibility to S. fulvus exists in previously released inbred lines, and how a new weevil‐resistant line, HA 488, compares with other putative sources of resistance. Correcting for the number of seeds per head, 13 older inbred lines showed variation in per cent seed damage from 20% to 38%, with two lines (HA 412 HO, HA 821) being more damaged than most of the tested lines. Among four putative resistance sources, HA 488 was significantly less damaged (5%) than two previously identified open‐pollinated varieties (PI 170424, PI 253417, with 13%–14% seed damage), while the source of the resistance in HA 488, PI 431542, was statistically intermediate (12%). The resistance available in HA 488 is a marked improvement, potentially reducing damage per weevil by two thirds or more, but additional work on genetic markers for resistance, economic thresholds and basic weevil biology (e.g. degree‐day models for adult emergence) is needed to support implementation of integrated pest management for this key sunflower pest.

中文翻译：

---

向日葵近交系对Smicronyx fulvus LeConte（鞘翅目：Curculionidae）的敏感性

红色的向日葵种子象鼻虫Smicronyx fulvus LeConte（鞘翅目：Curculionidae）是北美种植向日葵的主要食草害虫，Helianthus annuus L.。寄主植物抗性是补充基于杀虫剂的黄腐葡萄球菌防治的一种工具。每头30只成年象鼻虫的人工侵染被用来确定是否对黄花链球菌易感性发生变化以前发布的自交系中是否存在这种抗性，以及新的象鼻抗性品系HA 488与其他假定的抗性来源相比如何。校正了每头种子的数量后，有13个较早的近交系显示出20％到38％的种子损害百分率变化，其中两个系（HA 412 HO，HA 821）的损坏程度高于大多数测试系。在四个推定的抗性来源中，HA 488的损害程度（5％）明显低于先前确定的两个开放授粉品种（PI 170424，PI 253417，种子损害为13％–14％），而HA 488的抗性来源PI 431542在统计上处于中间水平（12％）。HA 488中的抗药性有了显着改善，可能使每只象鼻虫的伤害降低三分之二或更多，但有关抗药性遗传标记的其他工作