University of Minnesota, Department of Entomology, 1980 Folwell Ave, 219 Hodson Hall, Saint Paul, MN 55108, USA.
University of Minnesota, Department of Forest Resources, 2005 Upper Buford Cir., 115 Green Hall, Saint Paul, MN 55108, USA.
J Econ Entomol. 2023 Apr 24;116(2):496-504. doi: 10.1093/jee/toad023.
Nuts from hybrid hazels (Corylus americana Walter × Corylus avellana L.) are a burgeoning, novel industry for the Great Lakes region of the United States. As such, scant information exists about the pest complex, although stem-boring beetles in the genus Agrilus Curtis (Coleoptera: Buprestidae) have been noted by growers as potential pests. Here, we report results of a comprehensive survey of 186 plants in a hybrid hazel planting consisting of nine cultivars in southeastern Minnesota affected by stem borers. Sixteen percent of the hybrid hazel plants exhibited between 25 and 100% buprestid associated dieback. Morphological and molecular identification of the adult and larval buprestids colonizing hybrid hazel plants revealed that the hazel stem borer, Agrilus pseudocoryli Fisher, was the only species present. Adult A. pseudocoryli were observed on plants between 8 June and 13 July 2021. Plants with higher damage ratings from the hazel stem borer were more likely to exhibit signs of eastern filbert blight (Anisogramma anomala Peck), a fungal pathogen virulent to C. avellana. Some hazel cultivars were more susceptible to damage from stem borers than others. Taken together, our findings suggest that the hazel stem borer has the potential to impact hybrid hazelnut yield. We speculate that a regional drought may have promoted increased populations of the hazel stem borer, as native Agrilus species are often secondary pests that become problematic when environmental stresses decrease host resistance. More research is needed to elucidate interactions between hazels, buprestid pests, and environmental conditions to predict impacts on crop yields.
杂交榛子（Corylus americana Walter × Corylus avellana L.）的坚果在美国五大湖地区是一个新兴的、新颖的产业。因此，尽管种植者注意到钻蛀茎干的叶甲属（Agrilus Curtis）甲虫（鞘翅目：扁甲科）可能是潜在的害虫，但有关该害虫复合体的信息很少。在这里，我们报告了对明尼苏达州东南部一个杂交榛种植园的 186 株植物进行的一项综合调查结果，该种植园由 9 个品种组成，受到茎蛀虫的影响。16%的杂交榛植物表现出 25%至 100%的叶甲属相关衰退。对定植在杂交榛上的叶甲属成虫和幼虫的形态学和分子鉴定表明，榛茎蜂（Agrilus pseudocoryli Fisher）是唯一存在的物种。在 2021 年 6 月 8 日至 7 月 13 日期间观察到成虫在植物上活动。榛茎蜂造成的损害程度较高的植物更有可能出现东方榛枯萎病（Anisogramma anomala Peck）的迹象，这是一种对 C. avellana 具有致命性的真菌病原体。一些榛子品种比其他品种更容易受到茎蛀虫的损害。总的来说，我们的发现表明，榛茎蜂有可能影响杂交榛果的产量。我们推测，区域性干旱可能促进了榛茎蜂种群的增加，因为本地 Agrilus 物种通常是次要害虫，当环境压力降低宿主抗性时，它们就会成为问题。需要更多的研究来阐明榛子、叶甲科害虫和环境条件之间的相互作用，以预测对作物产量的影响。
