Grapevine red blotch virus (GRBV) is the causal agent of grapevine red blotch disease, which affects wine grapes and leads to reduced crop yield and quality. While some virus spread can be attributed to the propagation of infected plant material, a greenhouse assay recently demonstrated that the threecornered alfalfa hopper (Membracidae: Spissistilus festinus Say) can transmit GRBV between grapevines. While S. festinus is not considered an economic pest of wine grapes, this species is present in California vineyards and their feeding can cause petiole girdling. Recent surveys have noted a correlation between S. festinus populations and GRBV-positive vines in vineyard areas adjacent to riparian habitat. Here, S. festinus populations were monitored over a 2-yr period at multiple vineyard sites adjacent to riparian habitats. At each site, insects were sampled from ground covers and the vine canopy at the vineyard edge and interior, and vines in both locations were evaluated for petiole girdling. Results indicate that there was no difference in abundance of S. festinus at the vineyard edge and interior. Populations in the vine canopy were highest in the late spring and early summer, and this was followed by the appearance of petiole girdling, indicating a key period of potential GRBV transmission. Furthermore, activity in the vine canopy appears to be amplified when the quality of ground covers is reduced as the season progresses. That said, overall populations of S. festinus were relatively low and additional work is needed to characterize the timing and efficiency of transmission under field conditions.

中文翻译：

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河岸栖息地和地被植物对葡萄园三角紫花苜蓿（半翅目：膜科）种群的影响

葡萄红斑病病毒（GRBV）是葡萄红斑病的病原体，它影响酿酒葡萄并导致作物产量和品质下降。虽然一些病毒传播可归因于受感染植物材料的繁殖，但最近的一项温室试验表明，三角苜蓿漏斗（Membracidae：Spissistilus festinus Say）可以在葡萄藤之间传播 GRBV。虽然 S. festinus 不被认为是酿酒葡萄的经济害虫，但该物种存在于加利福尼亚的葡萄园中，它们的饲养会导致叶柄环剥。最近的调查已经注意到 S. festinus 种群与河岸栖息地附近葡萄园地区的 GRBV 阳性葡萄树之间存在相关性。在这里，S. festinus 种群在与河岸栖息地相邻的多个葡萄园地点进行了为期 2 年的监测。在每个站点，昆虫从葡萄园边缘和内部的地被植物和藤蔓树冠中取样，并评估了这两个位置的藤蔓的叶柄环剥。结果表明，葡萄园边缘和内部的 S. festinus 丰度没有差异。葡萄树冠层中的种群在春末夏初最高，其次是叶柄环剥的出现，表明是 GRBV 潜在传播的关键时期。此外，随着季节的进行，当地面覆盖物的质量下降时，葡萄树冠层的活动似乎会增强。也就是说，S. festinus 的总体数量相对较低，需要额外的工作来表征现场条件下传播的时间和效率。