Gulf Coast Research and Education Center, University of Florida, Wimauma, FL 33598, USA.
Gulf Coast Research and Education Center-Plant City Campus, University of Florida, Plant City, FL 33563, USA.
J Econ Entomol. 2024 Apr 12;117(2):585-594. doi: 10.1093/jee/toae007.
Scirtothrips dorsalis Hood (Thysanoptera: Thripidae) is an invasive, early-season pest of strawberry in Florida, causing feeding injury to young foliage that results in stunted plant growth and yield loss. Spinetoram, an effective insecticide for thrips pests with up to 3 applications per season permitted in strawberry, is often applied repeatedly during the early-season (Oct-Nov) to manage S. dorsalis, leaving few or no applications for flower thrips pests later in the season (Dec-Mar). Therefore, new strategies are needed to manage S. dorsalis with less insecticide, with the hypothesis that the first insecticide application can be delayed because young strawberry plants can compensate for minor feeding injury without compromising strawberry yield. Experiments conducted in strawberry field plots in Balm, FL, during 2018 and 2019 showed that delaying a spinetoram application for 14 days after infesting a plant with zero, 5, 10, or 20 S. dorsalis adults did not reduce the plant vigor and yield compared to spinetoram application after 4 days. Furthermore, young plants recovered from injury (10-30% bronzing injury on leaf veins and petioles) due to 1 or 2 S. dorsalis adults or larvae per trifoliate. A strategy of delaying the first spinetoram application when plants have 4-5 trifoliates should help reduce the number of insecticide applications needed for S. dorsalis management and reserve spinetoram applications for later in the season. Lower input costs in Florida strawberry without compromising yields due to thrips damage will improve the economics and sustainability of production systems.
稻黄蓟马（Scirtothrips dorsalis Hood）是佛罗里达州草莓的一种侵袭性、早期季节害虫，它会对幼叶造成取食伤害，导致植株生长受阻和产量损失。在草莓种植中，螺虫乙酯是一种防治蓟马害虫的有效杀虫剂，每季最多允许使用 3 次。然而，为了管理稻黄蓟马，通常会在早期季节（10 月至 11 月）反复多次使用螺虫乙酯，导致在季节后期（12 月至 3 月）几乎没有或没有应用于花蓟马害虫的药剂。因此，需要采用新的策略来减少杀虫剂用量来管理稻黄蓟马，其假设是可以延迟第一次施药，因为幼龄草莓植株可以在不影响草莓产量的情况下，对轻微的取食伤害进行补偿。在佛罗里达州巴尔姆的草莓田间小区进行的 2018 年和 2019 年的实验表明，与在感染后 4 天施药相比，在感染后 14 天再施药螺虫乙酯，对零、5、10 或 20 头稻黄蓟马成虫感染的植株活力和产量没有降低。此外，由于每三叶有 1 或 2 头稻黄蓟马成虫或幼虫造成的 10-30%叶片主脉和叶柄变褐的轻微损伤，幼龄植株能够恢复。当植株有 4-5 片复叶时，延迟第一次施药螺虫乙酯的策略应该有助于减少稻黄蓟马管理所需的杀虫剂施用量，并将螺虫乙酯的应用保留到季节后期。在不损害因蓟马危害而导致产量下降的情况下，降低佛罗里达州草莓的投入成本，将提高生产系统的经济效益和可持续性。
