Krauter Peter C, Heinz Kevin M, Arthurs Steven
Department of Entomology, Texas A&M University, 370 Olsen Blvd., College Station, TX 77843-2475.
J Insect Sci. 2017 Jul 1;17(4). doi: 10.1093/jisesa/iex056.
In North America, the sweetpotato whitefly, Bemisia tabaci Genn., is an important pest of greenhouse poinsettia. Growers have limited options to control this pest during propagation of cuttings, which are rooted under mist for several weeks. Early establishment of this pest increases the difficulty of managing the whitefly and retaining high aesthetic standard during the remaining crop production phase. We evaluated two neonicotinoids with translaminar activity, thiamethoxam (Flagship 25WG), and acetamiprid (TriStar 70 WSP), for control of B. tabaci pre-infested on unrooted cuttings propagated under mist. In an experimental greenhouse, both materials significantly reduced whitefly populations, providing an average reduction of 87.8% and 61.5% total recovered whitefly stages respectively, compared with controls. In another test, dipping cuttings in thiamethoxam (immersion treatment) did not improve control significantly, when compared with foliar sprays applied at label rate. In a commercial greenhouse operation, immersion treatments of thiamethoxam on pre-infested poinsettia cuttings maintained whiteflies at ≤ 0.02/plant, compared with up to 0.33/plant in untreated cuttings. Our data suggest that treating unrooted cuttings before or at the start of propagation can be part of an overall strategy for growers to manage whiteflies in poinsettia production.
在北美，烟粉虱（Bemisia tabaci Genn.）是温室一品红的一种重要害虫。在嫩枝扦插繁殖期间，种植者控制这种害虫的选择有限，嫩枝需在喷雾条件下生根数周。这种害虫的早期出现增加了在剩余作物生产阶段管理粉虱并保持高美学标准的难度。我们评估了两种具有跨层活性的新烟碱类药剂，噻虫嗪（锐胜25WG）和啶虫脒（顶峰70 WSP），用于控制在喷雾条件下繁殖的未生根嫩枝上预先侵染的烟粉虱。在一个试验温室中，与对照相比，两种药剂均显著减少了粉虱种群数量，分别使总回收粉虱虫态平均减少了87.8%和61.5%。在另一项试验中，与按标签剂量进行叶面喷雾相比，将嫩枝浸泡在噻虫嗪中（浸泡处理）并没有显著提高防治效果。在一个商业温室操作中，对预先侵染的一品红嫩枝进行噻虫嗪浸泡处理后，粉虱数量维持在≤0.02头/株，而未处理的嫩枝上粉虱数量高达0.33头/株。我们的数据表明，在繁殖前或繁殖开始时处理未生根嫩枝可以成为种植者在一品红生产中管理粉虱的总体策略的一部分。
